K a =
|
|
|
- Norma Hines
- 6 years ago
- Views:
Transcription
1 Q1.The acid dissociation constant, K a, for ethanoic acid is given by the expression K a = The value of K a for ethanoic acid is mol dm 3 at 25 C. A buffer solution is prepared using ethanoic acid and sodium ethanoate. In the buffer solution, the concentration of ethanoic acid is mol dm 3 and the concentration of sodium ethanoate is mol dm 3. Calculate the ph of this buffer solution. Give your answer to 2 decimal places. In a different buffer solution, the concentration of ethanoic acid is mol dm 3 and the concentration of sodium ethanoate is mol dm 3. A sample of hydrochloric acid containing mol of HCl is added to 1000 cm 3 of this buffer solution. Calculate the ph of the buffer solution after the hydrochloric acid has been added. You should ignore any change in total volume. Give your answer to 2 decimal places. Page 2
2 (5) (Total 8 marks) Q2.A solution of chlorine in water is acidic. Swimming pool managers maintain pool water at a constant ph by using a buffer. They do so by adding sodium hydrogencarbonate and sodium carbonate. Hydrogen carbonate ions (HCO 3 ) act as a weak acid in aqueous solution. Write an equation for this equilibrium. (1) Use the equation in part to explain how a solution containing sodium hydrogencarbonate and sodium carbonate can act as a buffer when small amounts of acid or small amounts of alkali are added. Page 3
3 (Total 4 marks) Q3.When 1.00 mol dm 3 solutions of salicylic acid and sodium hydroxide are mixed a buffer solution can be formed. Salicylic acid is a monoprotic acid that can be represented by the formula HA. Select a mixture from the table below that would produce a buffer solution. Give a reason for your choice. Mixture Volume of 1.00 mol dm 3 salicylic acid solution / cm 3 Volume of 1.00 mol dm 3 sodium hydroxide solution / cm 3 X Y Z Mixture... Reason... (2) Another mixture, formed by adding 50 cm 3 of 1.00 mol dm 3 salicylic acid solution to 25 cm 3 of 1.00 mol dm 3 sodium hydroxide solution, can be used to determine the pk a of salicylic acid. State one measurement that must be made for this mixture and explain how this measurement can be used to determine the pk a of salicylic acid. Measurement... Explanation... (Total 5 marks) Page 4
4 Q4.This question is about alkalis and carboxylic acids. In this question, all data are quoted at 25 C. Carboxylic acids are weak acids. State the meaning of the term weak as applied to carboxylic acids. (1) Write an equation for the reaction of propanoic acid with sodium carbonate. (1) (c) Calculate the ph of a mol dm 3 solution of calcium hydroxide. The ionic product of water K w = mol 2 dm 6. Give your answer to 2 decimal places. (Extra space)... (d) The value of the acid dissociation constant K a for benzenecarboxylic acid (C 6H 5COOH) is mol dm 3. (i) Write an expression for the acid dissociation constant K a for benzenecarboxylic acid. Page 5
5 (1) (ii) Calculate the ph of a mol dm 3 solution of benzenecarboxylic acid. Give your answer to 2 decimal places. (Extra space)... (iii) A buffer solution with a ph of 4.00 is made using benzenecarboxylic acid and sodium benzenecarboxylate. Calculate the mass of sodium benzenecarboxylate (M r = 144.0) that should be dissolved in 1.00 dm 3 of a mol dm 3 solution of benzenecarboxylic acid to produce a buffer solution with a ph of 4.00 The value of the acid dissociation constant K a for benzenecarboxylic acid (C 6H 5COOH) is mol dm 3. Page 6
6 (Extra space)... (5) (e) Two solutions, one with a ph of 4.00 and the other with a ph of 9.00, were left open to the air. The ph of the ph 9.00 solution changed more than that of the other solution. Suggest what substance might be present in the air to cause the ph to change. Explain how and why the ph of the ph 9.00 solution changes. Substance present in air... Explanation... (Total 17 marks) Q5.Ethanedioic acid is a weak acid. Ethanedioic acid acts, initially, as a monoprotic acid. Use the concept of electronegativity to justify why the acid strengths of ethanedioic Page 7
7 acid and ethanoic acid are different. (6) A buffer solution is made by adding mol of sodium hydroxide to a solution containing mol of ethanedioic acid (H 2C 2O 4). Assume that the sodium hydroxide reacts as shown in the following equation and that in this buffer solution, the ethanedioic acid behaves as a monoprotic acid. H 2C 2O 4(aq) + OH (aq) HC 2O 4 (aq) + H 2O(l) The dissociation constant K a for ethanedioic acid is mol dm 3. Calculate a value for the ph of the buffer solution. Give your answer to the appropriate number of significant figures. ph =... (5) (c) In a titration, the end point was reached when 25.0 cm 3 of an acidified solution containing ethanedioic acid reacted with cm 3 of mol dm 3 potassium manganate(vii) solution. Deduce an equation for the reaction that occurs and use it to calculate the original concentration of the ethanedioic acid solution. Page 8
8 Equation... Calculation Original concentration =... mol dm -3 (4) (Total 15 marks) Page 9
NH 3(aq) + H + (aq)
Q1.A solution of chlorine in water is acidic. Swimming pool managers maintain pool water at a constant ph by using a buffer. They do so by adding sodium hydrogencarbonate and sodium carbonate. (a) Hydrogen
Page 2. Q1.Water dissociates slightly according to the equation: H 2 O(I) The ionic product of water, K w, is given by the expression
Q1.Water dissociates slightly according to the equation: H 2 O(I) H + (aq) + OH (aq) The ionic product of water, K w, is given by the expression K w = [H + ][OH ] K w varies with temperature as shown in
ACIDS, BASES, PH, BUFFERS & TITRATION WEBINAR. Dr Chris Clay
ACIDS, BASES, PH, BUFFERS & TITRATION WEBINAR Dr Chris Clay http://drclays-alevelchemistry.com/ Q1.Titration curves, labelled E, F, G and H, for combinations of different aqueous solutions of acids and
State the strongest type of interaction that occurs between molecules of hydrogen peroxide and water.
Q1.A hydrogen peroxide molecule can be represented by the structure shown. (a) Suggest a value for the H O O bond angle. (b) Hydrogen peroxide dissolves in water. (i) State the strongest type of interaction
Page 2. Q1.Water dissociates slightly according to the equation: H 2 O(I) The ionic product of water, K w, is given by the expression
Q1.Water dissociates slightly according to the equation: H 2 O(I) H + (aq) + OH (aq) The ionic product of water, K w, is given by the expression K w = [H + ][OH ] K w varies with temperature as shown in
Titration curves, labelled E, F, G and H, for combinations of different aqueous solutions of acids and bases are shown below.
Titration curves, labelled E, F, G and H, for combinations of different aqueous solutions of acids and bases are shown below. All solutions have concentrations of 0. mol dm 3. (a) In this part of the question,
, for C 2. COOH is mol dm [1] COOH by adding water until the total volume is cm 3. for C 2 COOH.
![, for C 2. COOH is mol dm [1] COOH by adding water until the total volume is cm 3. for C 2 COOH.](/thumbs/74/70636476.jpg ", for C 2. COOH is mol dm [1] COOH by adding water until the total volume is cm 3. for C 2 COOH.")
1 A student is supplied with 0.500 mol dm 3 potassium hydroxide, KOH, and 0.480 mol dm 3 propanoic acid, C 2 COOH. The acid dissociation constant, K a, for C 2 COOH is 1.35 10 5 mol dm 3. (a) C 2 COOH
(14) WMP/Jun10/CHEM4
Acids, Bases and ph 14 5 In this question, give all values of ph to two decimal places. Calculating the ph of aqueous solutions can involve the use of equilibrium constants such as K w and K a K w is the
14-Jul-12 Chemsheets A
www.chemsheets.co.uk 14-Jul-12 Chemsheets A2 009 1 BRONSTED-LOWRY ACIDS & BASES Bronsted-Lowry acid = proton donor (H + = proton) Bronsted-Lowry base = proton acceptor (H + = proton) Bronsted-Lowry acid-base
D. Ammonia can accept a proton. (Total 1 mark)
1. Which statement explains why ammonia can act as a Lewis base? A. Ammonia can donate a lone pair of electrons. B. Ammonia can accept a lone pair of electrons. C. Ammonia can donate a proton. D. Ammonia
... (iii) Calculate the ph of the solution formed when 10.0 cm 3 of mol dm 3 hydrochloric acid are added to 990 cm 3 of water
Q1. This question is about the ph of several solutions. Give all values of ph to 2 decimal places. (a) (i) Write an expression for ph. Calculate the ph of 0.154 mol dm 3 hydrochloric acid. (iii) Calculate
(i) Calculate the amount, in moles, of HCl in 33.2 cm 3 of mol dm 3 hydrochloric acid. Give your answer to 3 significant figures. ...
Q1. (a) An unknown metal carbonate reacts with hydrochloric acid according to the following equation. M 2CO 3(aq) + 2HCl(aq) 2MCl(aq) + CO 2(g) + H 2O(l) A 3.44 g sample of M 2CO 3 was dissolved in distilled
12. Acid Base Equilibria
2. Acid Base Equilibria BronstedLowry Definition of acid Base behaviour A BronstedLowry acid is defined as a substance that can donate a proton. A BronstedLowry base is defined as a substance that can
5.1.3 Acids, Bases and Buffers
5..3 Acids, Bases and Buffers BronstedLowry Definition of Acid Base behaviour A BronstedLowry acid is defined as a substance that can donate a proton. A BronstedLowry base is defined as a substance that
(a) Hydrogen sulfide is a weak acid and dissociates in two stages as shown. Write the K a expressions for (2)
1 Sulfuric acid, H 2 SO 4, is a well nown acid containing sulfur. However, two other sulfur-containing acids are hydrogen sulfide, H 2 S, and sulfurous acid, H 2 SO 3. (a) Hydrogen sulfide is a wea acid
4. Acid Base Equilibria
4. Acid Base Equilibria BronstedLowry Definition of acid Base behaviour A BronstedLowry acid is defined as a substance that can donate a proton. A BronstedLowry base is defined as a substance that can
1.12 Acid Base Equilibria
.2 Acid Base Equilibria BronstedLowry Definition of acid Base behaviour A BronstedLowry acid is defined as a substance that can donate a proton. A BronstedLowry base is defined as a substance that can
5 Acid Base Reactions
Aubrey High School AP Chemistry 5 Acid Base Reactions 1. Consider the formic acid, HCOOH. K a of formic acid = 1.8 10 4 a. Calculate the ph of a 0.20 M solution of formic acid. Name Period Date / / 5.2
*P51939A0124* Pearson Edexcel WCH04/01. P51939A 2018 Pearson Education Ltd.
Write your name here Surname Other names Pearson Edexcel International Advanced Level Centre Number Candidate Number Chemistry Advanced Unit 4: General Principles of Chemistry I Rates, Equilibria and Further
ANSWERS Unit 14: Review Acids and Bases
ANSWERS Unit 14: Review Acids and Bases 1) CH 3 COOH(aq) + H 2 0(l) H 3 0 + (aq) + CH 3 COO - (aq) In the equilibrium above, what are the two conjugate bases? A. CH 3 COOH and H 2 0 B. CH 3 COO - and H
The presence of these ions can be confirmed by reacting separate samples of solution X with aqueous ammonia and with aqueous sodium carbonate. ...
Q1.A green solution, X, is thought to contain [Fe(H 2 O) 6 ] 2+ ions. The presence of these ions can be confirmed by reacting separate samples of solution X with aqueous ammonia and with aqueous sodium
Acid Base Equilibria
Acid Base Equilibria Acid Ionization, also known as acid dissociation, is the process in where an acid reacts with water to produce a hydrogen ion and the conjugate base ion. HC 2 H 3 O 2(aq) H + (aq)
A2 LEVEL CHEMISTRY ACIDS, BASES AND BUFFERS TEST
A2 LEVEL CHEMISTRY 5.1.3 ACIDS, BASES AND BUFFERS TEST Answer all questions Max 50 marks Name.. Mark../50...% Grade Paddington Academy 1 1. A student carried out an investigation with aqueous solutions
Acid Base Equilibria
Acid Base Equilibria N Goalby Chemrevise.org ACIDBASE : Arrhenius The most basic of the acidbase concepts is the Arrhenius theory Acids are substances that dissociate in water to produce hydronium ions,
+(aq) + Cl - (aq) HA(aq) A - (aq) + H + (aq) CH 3COO - (aq) + H + (aq)
1 A2 Chemistry: F325 Equilibria, Energetics and Elements 5.1.3 Acids, Bases and Buffers. Lesson 6 Buffer Solutions. Learning Outcomes: All Describe what is meant by the term buffer solution (5.1.3 k) Explain
2.67 g (Total 1 mark)
Q1. The chloride of an element Z reacts with water according to the following equation. Zl 4(l) + 2H 2O(l) ZO 2(s) + 4Hl(aq) 1.304 g sample of Zl 4 was added to water. The solid ZO 2 was removed by filtration
Chemical Equilibria Part 2
Unit 1 - Inorganic & Physical Chemistry 1.4 Chemical Equilibria Part 2 Acid / Base Equilibria Indicators ph Curves Buffer Solutions Pupil Notes Learning Outcomes Questions & Answers KHS ChemistrySept 2015
2 Answer all the questions. 1 Born Haber cycles can be used to calculate enthalpy changes indirectly.
2 Answer all the questions. 1 Born Haber cycles can be used to calculate enthalpy changes indirectly. (a) The table below shows enthalpy changes for a Born Haber cycle involving potassium sulfide, K 2
Test: Acid Base. 2. The ph value of a 1.00 x 10-3 mol dm -3 solution of sodium hydroxide is: A. 3. B. 8. C. 11. D. 14.
Test: Acid Base SCH3U_ 2010-2011 Name: (Test Score: / 40) Multiple Choice ( 6) 1. A Brønsted-Lowry base is defined as a substance which: A. accepts H +1 ions. B. produces OH -1 ions. C. conducts electricity.
+ H 2 O HPO 4. (a) In this system, there are two acid-base conjugate pairs. These are (1) HPO4
1 The dihydrogenphosphate-hydrogenphosphate ion system is an important buffer in the human body. H 2 PO 4 H 2 O HPO 4 2 H 3 O (a) In this system, there are two acid-base conjugate pairs. These are acid
OCR A Chemistry A-Level Module 5 - Physical Chemistry & Transition Elements
OCR A Chemistry A-Level Module 5 - Physical Chemistry & Transition Elements Acids and Bases Notes and Example Calculations Answers given at the end of the booklet ph Acid Calculations Strong Acids To calculate
5.1 Module 1: Rates, Equilibrium and ph
5.1 Module 1: Rates, Equilibrium and ph 5.1.1 How Fast? The rate of reaction is defined as the change in concentration of a substance in unit time Its usual unit is mol dm 3 s 1 When a graph of concentration
mohd faisol mansor/chemistry form 4/chapter 7 CHAPTER 7 ACIDS AND BASES HCl (g) H 2 O H + (aq) + Cl - (aq) NaOH(s) H 2 O Na + (aq) + OH - (aq)
CHAPTER 7 ACIDS AND BASES Arrhenius Theory An acid is a chemical compound that produces hydrogen ions, H + or hydroxonium ions H3O + when dissolve in water. A base defined as a chemical substance that
2 Answer all the questions. 1 Born Haber cycles can be used to determine lattice enthalpies of ionic compounds
2 Answer all the questions. 1 Born Haber cycles can be used to determine lattice enthalpies of ionic compounds. (a) Define, in words, the term lattice enthalpy............. [2] (b) The Born Haber cycle
A-level CHEMISTRY (7405/3)
SPECIMEN MATERIAL A-level CHEMISTRY (7405/3) Paper 3 Specimen 2015 Session Time allowed: 2 hours Materials For this paper you must have: the Data Booklet, provided as an insert a ruler a calculator. Instructions
Mass of g measured with a balance with an uncertainty of ±0.001 g.
Q1.Which of these pieces of apparatus has the lowest percentage uncertainty in the measurement shown? Volume of 25 cm 3 measured with a burette with an uncertainty of ±0.1 cm 3. Volume of 25 cm 3 measured
Page 2. M1.(a) [H + ] = or = Allow ( ) M1 1 = If [HX] / [X - ] or M2. M2 1
![Page 2. M1.(a) [H + ] = or = Allow ( ) M1 1 = If [HX] / [X - ] or M2. M2 1](/thumbs/76/73923850.jpg "Page 2. M1.(a) [H + ] = or = Allow ( ) M1 1 = If [HX] / [X - ] or M2. M2 1")
M.(a) [H + ] = or =.74 0 5 Allow ( ) M = 3.08 0 5 If [HX] / [X - ] or. upside down, or any addition or subtraction lose M & ph = 4.5 (correct answer scores 3) Can score for correct ph conseq to their [H
Use the concept of electronegativity to justify why the acid strengths of ethanedioic acid and ethanoic acid are different
Which molecule has the largest dipole? A ClF 3 B BF 3 C SF 6 D CF 4 (Total mark) 2 Which of these atoms has the highest electronegativity? A B C D Na Mg Cl Ar (Total mark) 3 Ethanedioic acid is a weak
Complete the table to show the relative charge of each particle and the number of each particle found in a 140 Ce 2+ ion.
1 This question is about the elements with atomic numbers between 58 and 70 (a) Cerium, atomic number 58, is a metal Complete the table to show the relative charge of each particle and the number of each
A-level CHEMISTRY 7405/1. Paper 1: Inorganic and Physical Chemistry. SPECIMEN MATERIAL v1.2
SPECIMEN MATERIAL v1.2 Please write clearly in block capitals. Centre number Candidate number Surname Forename(s) Candidate signature A-level CHEMISTRY Paper 1: Inorganic and Physical Chemistry Specimen
1. An aqueous solution of which of the following reacts with magnesium metal?
1 1. An aqueous solution of which of the following reacts with magnesium metal? A. Ammonia B. Hydrogen chloride C. Potassium hydroxide D. Sodium hydrogencarbonate 2. Which one of the following species
Show by calculation that the starting concentration of the manganate(vii) ions was mol dm 3.
1. Manganate(VII) ions react with ethanedioate ions in acidic solution. MnO 4 (aq) + 16H + (aq) + 5C O 4 (aq) Mn + (aq) + 8H O(l) + 10CO (g) (a) In a particular experiment 00 cm of aqueous potassium manganate(vii),
QUESTIONSHEETS ACID - BASE EQUILIBRIA. ph OF STRONG ACIDS AND BASES. AND pk a. ph OF ACID OR BASE SOLUTIONS. ph OF MIXED SOLUTIONS OF ACID AND BASE
CHEMISTRY QUESTIONSHEETS A2 Level A2 TOPIC 19 ACID - BASE EQUILIBRIA Questionsheet 1 Questionsheet 2 Questionsheet 3 Questionsheet 4 Questionsheet 5 Questionsheet 6 Questionsheet 7 Questionsheet 8 Questionsheet
TOPIC 19 ANSWERS & MARK SCHEMES QUESTIONSHEET 1. ph AND K W
QUESTIONSHEET 1 a) ph - lg [H + ] / lg 1 [H + ] b) Water ionises slightly as follows: H 2 O(l) ž H + (aq) + OH - (aq) [H + (aq)][oh - (aq)] K c [H 2 O(l)] Since the ionisation is very slight, we regard
Lesmahagow High School AHChemistry Inorganic and Physical Chemistry Lesmahagow High School CfE Advanced Higher Chemistry
Lesmahagow High School CfE Advanced Higher Chemistry Unit 1 Inorganic and Physical Chemistry Chemical Equilibrium 1 Dynamic Equilibrium Revision Dynamic equilibrium happens in a closed system when the
4.3 ANSWERS TO EXAM QUESTIONS
4. ANSWERS TO EXAM QUESTIONS. (a) (i) A proton donor () (ii) Fully ionised or fully dissociated () (iii) 0 0 4 () mol dm 6 () 4 (b) (i) 50 0 /5 000 () = 0 06 mol dm () () (ii) Mol OH added = 50 0 50/000
NH 3(g) N 2(g) + H 2(g) What is the total number of moles of gas present in this equilibrium mixture? D 3.0 (Total 1 mark)
Q1.When one mole of ammonia is heated to a given temperature, 50% of the compound dissociates and the following equilibrium is established. NH 3(g) N 2(g) + H 2(g) What is the total number of moles of
Atoms, Elements, Atoms, Elements, Compounds and Mixtures. Compounds and Mixtures. Atoms and the Periodic Table. Atoms and the.
Atoms, Elements, Compounds and Mixtures Explain how fractional distillation can be used to separate a mixture. 1 Atoms, Elements, Compounds and Mixtures Fractional distillation is used to separate components
Paper Reference. Paper Reference(s) 6246/02 Edexcel GCE Chemistry Advanced Unit Test 6B (Synoptic)
Centre No. Paper Reference Surname Initial(s) Candidate No. 6 2 4 6 0 2 Signature Paper Reference(s) 6246/02 Edexcel GCE Chemistry Advanced Unit Test 6B (Synoptic) Tuesday 28 June 2005 Morning Time: 1
2 Answer all the questions. CO, in the presence of aqueous hydrochloric acid, HCl(aq).
2 Answer all the questions. 1 A student investigates the reaction between iodine, I 2, and propanone, (CH 3 ) 2 CO, in the presence of aqueous hydrochloric acid, HCl(aq). The results of the investigation
2 Answer all the questions.
2 Answer all the questions. 1 Born Haber cycles provide a model that chemists use to determine unknown enthalpy changes from known enthalpy changes. In this question, you will use a Born Haber cycle to
AS Paper 1 and 2 Kc and Equilibria
AS Paper 1 and 2 Kc and Equilibria Q1.When one mole of ammonia is heated to a given temperature, 50 per cent of the compound dissociates and the following equilibrium is established. NH 3(g) ½ N 2 (g)
PRACTICAL QUESTIONS TEST TUBE REACTIONS 4&11 Questions. Dr Chris Clay
PRACTICAL QUESTIONS TEST TUBE REACTIONS 4&11 Questions Dr Chris Clay http://drclays-alevelchemistry.com/ Q1.(a) A sample of solid chromium(iii) hydroxide displays amphoteric character when treated separately
School of Chemistry, University of KwaZulu-Natal, Howard College Campus, Durban. CHEM191 Tutorial 1: Buffers
School of Chemistry, University of KwaZulu-Natal, Howard College Campus, Durban CHEM191 Tutorial 1: Buffers Preparing a Buffer 1. How many moles of NH 4 Cl must be added to 1.0 L of 0.05 M NH 3 to form
Chemistry 30 Mr. de Bruin Unit 3 Assignment.
NAME: Chemistry 30 Mr. de Bruin Unit 3 Assignment. All work must be fully shown in all questions to get process marks. As this is a summative assessment item, questions of clarification may be asked, but
Acids, Bases and Buffers
1 Acids, Bases and Buffers Strong vs weak acids and bases Equilibrium as it relates to acids and bases ph scale: [H+(aq)] to ph, poh, etc ph of weak acids ph of strong acids Conceptual about oxides (for
moulsham high school 1
moulsham high school 1 a) Interpret the natural direction of change (spontaneous change) as the direction of increasing number of ways of sharing energy and therefore of increasing entropy (positive entropy
Transition Metals Webinar Qs
1. This diagram represents the energy change that occurs when a d electron in a transition metal ion is excited by visible light. (a) Give the equation that relates the energy change ΔE to the Planck constant
Monday 19 June 2017 Morning
Oxford Cambridge and RSA Monday 19 June 2017 Morning A2 GCE CHEMISTRY A F325/01 Equilibria, Energetics and Elements *6765485324* Candidates answer on the Question Paper. OCR supplied materials: Data Sheet
+ 10Cl 2Mn H 2 O + 5Cl 2. Deduce the half-equation for the oxidation of chloride ions to chlorine.
Q1.Chlorine is an important industrial chemical. (a) Chlorine is formed when KMnO 4 reacts with hydrochloric acid. The ionic equation for this redox reaction is 16H + + 2MnO 4 + 10Cl 2Mn 2+ + 8H 2 O +
Acid Base Reactions. Reading: Ch 4 section 8 Homework: Chapter 4: 79, 81*, 83*, 108 (optional)
Acid Base Reactions Reading: Ch 4 section 8 Homework: Chapter 4: 79, 81*, 83*, 108 (optional) * = important homework question Background Recall: Acids and bases are special in two ways: What is special
cm mol l -1 NaOH added to 50.0 cm 3 of 0.10 mol l -1 HCl
cm 3 0.10 mol l -1 NaOH added to 50.0 cm 3 of 0.10 mol l -1 HCl Acids have been described as substances that dissolve in water to form H + (aq) ions, whilst bases are substances that react with acids.
American International School of Johannesburg. Quantitative Revision Questions II
American International School of Johannesburg Quantitative Revision Questions II 1. A toxic gas, A, consists of 53.8 % nitrogen and 46.2 % carbon by mass. At 273 K and 1.01 10 5 Pa, 1.048 g of A occupies
Strong & Weak Acid (ph, pka, Kw) Question Paper
For more awesome GSE and level resources, visit us at www.savemyexams.co.uk/ Strong & Weak cid (ph, pka, Kw) Question Paper Level Subject Exam oard Topic Sub Topic ooklet Paper Type Level hemistry Edexcel
least reactive magnesium
1 One way of establishing a reactivity series is by displacement reactions. (a) A series of experiments was carried out using the metals lead, magnesium, zinc and silver. Each metal was added in turn to
M1. (a) ph = log[h + ] 1. ph = 2.79 (penalise 1 dp or more than 2dp once in the qu) despite the addition of (small amounts of) acid/base (or dilution)
![M1. (a) ph = log[h + ] 1. ph = 2.79 (penalise 1 dp or more than 2dp once in the qu) despite the addition of (small amounts of) acid/base (or dilution)](/thumbs/82/86175821.jpg "M1. (a) ph = log[h + ] 1. ph = 2.79 (penalise 1 dp or more than 2dp once in the qu) despite the addition of (small amounts of) acid/base (or dilution)")
M. (a) ph = log[h + ] [H + ]=.74 0 5 0.5 (or.62 0 3 ) ph = 2.79 (penalise dp or more than 2dp once in the qu) (b) (i) Solution which resists change in ph /maintains ph despite the addition of (small amounts
( 1 ) Concept of acid / base
Section 6.2 Ionic Equilibrium Unit 628 ( 1 ) Concept of acid / base The best definition of acids and bases is that proposed by T.M. Lowry and also, independently by J.N. Bronsted in 1923. BronstedLowry
COOH, and thioglycolic acid, HSCH 2. (a) Glycolic acid reacts with bases, such as aqueous sodium hydroxide, NaOH(aq), to form salts.
1 Glycolic acid, HOCH 2 COOH, and thioglycolic acid, HSCH 2 COOH, are weak acids. (a) Glycolic acid reacts with bases, such as aqueous sodium hydroxide, NaOH(aq), to form salts. A student pipetted 25.0
Level 2 Chemistry, 2017
91166 911660 2SUPERVISOR S Level 2 Chemistry, 2017 91166 Demonstrate understanding of chemical reactivity 2.00 p.m. Thursday 16 November 2017 Credits: Four Achievement Achievement with Merit Achievement
Chemistry 192 Problem Set 3 Spring, 2018 Solutions
Chemistry 19 Problem Set 3 Spring, 018 Solutions 1. Problem 3, page 78, textbook Answer (a) (b) (c) (d) HOBr (acid 1) + HSO 4 (acid 1) + HS (base 1) + C 6 H 5 NH + 3 (acid 1) + H O (base ) H 3O + (acid
Acid Base Titrations
ChemActivity CA47b Acid Base Titrations Model 1 Titration of a strong acid with a strong base. 20.00 ml of HNO 3 is titrated with 0.10 M NaOH. The acid-base reaction is The net ionic reaction is HNO 3
No Brain Too Small CHEMISTRY AS90700 Describe properties of aqueous systems. ph of weak acids, weak bases and salt solutions
ph of weak acids, weak bases and salt solutions 2010: 1 An aqueous solution of ammonium chloride (NH 4 Cl) has a ph of 4.66. (a) (i) Write the equation for solid ammonium chloride dissolving in water.
Unit Nine Notes N C U9
Unit Nine Notes N C U9 I. AcidBase Theories A. Arrhenius Acids and Bases 1. Acids contain hydronium ions (H O ) commonly referred to as hydrogen ions (H ) that dissociate in water a. Different acids release
Unit 4: General Principles of Chemistry I Rates, Equilibria and Further Organic Chemistry (including synoptic assessment)
Write your name here Surname Other names Edexcel GCE Centre Number Candidate Number Chemistry Advanced Unit 4: General Principles of Chemistry I Rates, Equilibria and Further Organic Chemistry (including
1 Three redox systems, C, D and E are shown in Table 6.1. C Ag(NH 3. ) 2 + (aq) + e Ag(s) + 2NH 3. (aq) D Ag + (aq) + e Ag(s)
1 Three redox systems, C, D and E are shown in Table 6.1. C Ag(NH 3 ) 2 + (aq) + e Ag(s) + 2NH 3 (aq) D Ag + (aq) + e Ag(s) E Ag(CN) 2 (aq) + e Ag(s) + 2CN (aq) Table 6.1 The two cells below were set up
Arrhenius base is one that dissociates in water to form hydroxide ions.
Chemistry Notes: Acids and Bases Arrhenius base is one that dissociates in water to form hydroxide ions. Arrhenius acid is on that dissociates in water to form hydrogen ions (protons). A Bronsted-Lowry
Q13 (a) PENALISE USE OF CH 3 COOH / ethanoic acid [instead of propanoic acid] once only. ALLOW NaOH for KOH, however.
![Q13 (a) PENALISE USE OF CH 3 COOH / ethanoic acid [instead of propanoic acid] once only. ALLOW NaOH for KOH, however.](/thumbs/81/82932828.jpg "Q13 (a) PENALISE USE OF CH 3 COOH / ethanoic acid [instead of propanoic acid] once only. ALLOW NaOH for KOH, however.")
1 (a)(i) Q13 (a) PENALISE USE OF CH 3 COOH / ethanoic acid [instead of propanoic acid] once only. ALLOW NaOH for KOH, however. 1st mark: Identification of buffer Any mention of buffer / buffering (region)
T8-1P1 [212 marks] [1 mark] Which is an acid-base conjugate pair? A. H3 O / OH B. H2SO 4 / SO4 C. CH3COOH / H3 O D. CH3NH 3 + / CH3NH2.
![T8-1P1 [212 marks] [1 mark] Which is an acid-base conjugate pair? A. H3 O / OH B. H2SO 4 / SO4 C. CH3COOH / H3 O D. CH3NH 3 + / CH3NH2.](/thumbs/89/100188411.jpg "T8-1P1 [212 marks] [1 mark] Which is an acid-base conjugate pair? A. H3 O / OH B. H2SO 4 / SO4 C. CH3COOH / H3 O D. CH3NH 3 + / CH3NH2.")
T8-1P1 [212 marks] 1. Which is an acid-base conjugate pair? A. H3 O / OH B. H2SO 4 / SO4 C. CH3COOH / H3 O D. CH3NH 3 + / CH3NH2 2. Which of the following is correct? A. A weak acid is a proton donor and
B410U10-1 S16-B410U10-1. CHEMISTRY Component 1 The Language of Chemistry, Structure of Matter and Simple Reactions
Surname Centre Number Candidate Number Other Names 2 GCE AS NEW AS B410U10-1 S16-B410U10-1 CHEMISTRY Component 1 The Language of Chemistry, Structure of Matter and Simple Reactions A.M. FRIDAY, 27 May
burette filled with sulphuric acid conical flask 25.0 cm 3 of sodium hydroxide(aq) concentration 2.24 mol / dm 3
1 Crystals of sodium sulphate-10-water, Na 2 SO 4.10H 2 O, are prepared by titration. burette filled with sulphuric acid conical flask 25.0 cm 3 of sodium hydroxide(aq) concentration 2.24 mol / dm 3 (a)
Equilibrium Practice Test
Equilibrium Practice Test Name: ANSWERS Multiple Choice Identify the letter of the choice that best completes the statement or answers the question. (20 marks) 60 /60 1. Equilibrium happens when. a. opposing
OCR (A) Chemistry A-level Topic Acids, Bases and Buffers
OCR (A) Chemistry A-level Topic 5.1.3 - Acids, Bases and Buffers Flashcards Define a Bronsted-Lowry acid Define a Bronsted-Lowry acid Proton donor Define a Bronsted-Lowry base Define a Bronsted-Lowry base
Assessment Schedule 2015 Chemistry: Demonstrate understanding of chemical reactivity (91166)
NCEA Level 2 Chemistry (91166) 2015 page 1 of 6 Assessment Schedule 2015 Chemistry: Demonstrate understanding of chemical reactivity (91166) Evidence Statement Q Evidence Achievement Achievement with Merit
Chem!stry. Mole Calculations Assignment Twelve
Chem!stry Name: ( ) Class: Date: / / Mole Calculations Assignment Twelve 1. A gas is 46.2% carbon and 53.8% nitrogen. Under conditions of room temperature and pressure (r.t.p.) the volume of the gas is
Acids, Bases, & Neutralization Chapter 20 & 21 Assignment & Problem Set
Acids, Bases, & Neutralization Name Warm-Ups (Show your work for credit) Date 1. Date 2. Date 3. Date 4. Date 5. Date 6. Date 7. Date 8. Acids, Bases, & Neutralization 2 Study Guide: Things You Must Know
Cambridge International Examinations Cambridge International Advanced Subsidiary and Advanced Level
Cambridge International Examinations Cambridge International Advanced Subsidiary and Advanced Level *0134962560* CHEMISTRY 9701/41 Paper 4 A Level Structured Questions October/November 2018 2 hours Candidates
ADVANCED PLACEMENT CHEMISTRY ACIDS, BASES, AND AQUEOUS EQUILIBRIA
ADVANCED PLACEMENT CHEMISTRY ACIDS, BASES, AND AQUEOUS EQUILIBRIA Acids- taste sour Bases(alkali)- taste bitter and feel slippery Arrhenius concept- acids produce hydrogen ions in aqueous solution while
Three experiments were carried out using different initial concentrations of the three reactants x 10 5
1 Bromate(V) ions, BrO 3, oxidize bromide ions, Br, in the presence of dilute acid, H +, as shown in the equation below. BrO 3 (aq) + 5Br (aq) + 6H + (aq) 3Br 2 (aq) + 3H 2 O(l) Three experiments were
1. Which statement is correct for a crystal of iron(ii) sulfate in a state of equilibrium with a saturated solution of iron(ii) sulfate?
1. Which statement is correct for a crystal of iron(ii) sulfate in a state of equilibrium with a saturated solution of iron(ii) sulfate? A. The colour of the solution darkens as the crystal continues to
ph calculations MUDr. Jan Pláteník, PhD Brønsted-Lowry concept of acids and bases Acid is a proton donor Base is a proton acceptor
ph calculations MUDr. Jan Pláteník, PhD Brønsted-Lowry concept of acids and bases Acid is a proton donor Base is a proton acceptor HCl(aq) + H 2 O(l) H 3 O + (aq) + Cl - (aq) Acid Base Conjugate acid Conjugate
ACIDS AND BASES. Note: For most of the acid-base reactions, we will be using the Bronsted-Lowry definitions.
DEFINITIONS: ACIDS AND BASES Arrhenius Definition An acid in aqueous solution produces H + ions. A base in aqueous solution produces OH - ions. Bronsted Lowry Theory An acid is a proton donor A base is
The Equilibrium Law. Calculating Equilibrium Constants. then (at constant temperature) [C] c. [D] d = a constant, ( K c )
![The Equilibrium Law. Calculating Equilibrium Constants. then (at constant temperature) [C] c. [D] d = a constant, ( K c )](/thumbs/79/79140820.jpg "The Equilibrium Law. Calculating Equilibrium Constants. then (at constant temperature) [C] c. [D] d = a constant, ( K c )")
Chemical Equilibrium 1 The Equilibrium Law States If the concentrations of all the substances present at equilibrium are raised to the power of the number of moles they appear in the equation, the product
For the element X in the ionic compound MX, explain the meaning of the term oxidation state.
1. (a) By referring to electrons, explain the meaning of the term oxidising agent.... For the element X in the ionic compound MX, explain the meaning of the term oxidation state.... (c) Complete the table
Acids and Bases. Reviewing Vocabulary CHAPTER ASSESSMENT CHAPTER 19. Compare and contrast each of the following terms.
Acids and Bases Reviewing Vocabulary Compare and contrast each of the following terms. 1. Arrhenius model, Brønsted-Lowry model 2. acid ionization constant, base ionization constant 3. conjugate acid,
A student adds the following volumes of aqueous sodium thiosulfate, dilute hydrochloric acid and distilled water to the conical flask.
1 When aqueous sodium thiosulfate and dilute hydrochloric acid are mixed, a precipitate of insoluble sulfur is produced. This makes the mixture difficult to see through. Na 2 S 2 O 3 (aq) + 2HCl (aq) S(s)
Page 2. Q1.The following pairs of compounds can be distinguished by simple test tube reactions.
Q1.The following pairs of compounds can be distinguished by simple test tube reactions. For each pair of compounds, give a reagent (or combination of reagents) that, when added separately to each compound,
Quiz name: Equilibria + Acids/Bases
Name: Quiz name: Equilibria + Acids/Bases Date: 1. 2. At 450 C, 2.0 moles each of H 2(g), I 2(g), and HI are combined in a 1.0 L rigid container. The value of K c at 450 C is 50. Which of the following
Buffers. How can a solution neutralize both acids and bases? Beaker B: 100 ml of 1.00 M HCl. HCl (aq) + H 2 O H 3 O 1+ (aq) + Cl 1 (aq)
Buffers How can a solution neutralize both acids and bases? Why? Buffer solutions are a mixture of substances that have a fairly constant ph regardless of addition of acid or base. They are used in medicine,
Lecture Presentation. Chapter 16. Acid Base Equilibria. John D. Bookstaver St. Charles Community College Cottleville, MO Pearson Education, Inc.
Lecture Presentation Chapter 16 Acid Base Equilibria John D. Bookstaver St. Charles Community College Cottleville, MO Some Definitions Arrhenius An acid is a substance that, when dissolved in water, increases
2014 AP CHEMISTRY FREE-RESPONSE QUESTIONS
2014 AP CHEMISTRY FREE-RESPONSE QUESTIONS CH 3 CH 2 COOH(aq ) + H 2 O(l) CH 3 CH 2 COO (aq ) + H 3 O + (aq ) 2. Propanoic acid, CH 3 CH 2 COOH, is a carboxylic acid that reacts with water according to