Example: How many significant figures are in the measured number ml? (5)

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1 Chem 143 Final Exam Study Guide 1.) Know significant figures. Example: How many significant figures are in the measured number ml? (5) 2.) Know how to use dimensional analysis. Example: A pipe in your ceiling is leaking at a rate of 148 ml/hour. The water coming out has lead in it at a concentration of 21.2 mg Pb/750. ml. How many mg of lead per hour is leaking out? (4.18mg/hour) 3.) Know the states of matter and their descriptions. Example: Which state of matter has variable shape and is easily compressed? (gas) 4.) Know the difference between a heterogeneous mixture and a homogeneous mixture. Example: Which is a heterogeneous mixture, a cup of tea or a glass of orange juice with pulp in it? (orange juice) 5.) Know how to convert between Kelvins and degrees Celsius. Example: How do you convert 142 K to o C? (142K = -131 o C) 6.) Know the density formula and how to use it. Example: A solution has a density of 5.19 kg/l. How much does 3.50 L of this solution weigh? (18.2 kg) 7.) Know how to balance chemical equations. Example: When the following equation is properly balanced, what is the coefficient for O 2? (7) CH 3 CH 2 CH 2 OH + O 2 CO 2 + H 2 O 8.) Know how to calculate molar mass. Example: What is the molar mass of K 2 Cr 2 O 7? ( g/mol) 9.) Know how to use molar mass as a conversion factor. Example: How many moles of sucrose are there in 148 mg of sucrose, C 12 H 22 O 11? (The molar mass of sucrose is g/mol) (4.32x10-4 mol) Page 1 of 6

2 10.) Know your stoichiometry (mole to mole ratios from balanced equations). Example: How many moles of iron(iii) oxide can be produced by the reaction of 1.74 moles of iron according to the following balanced equation? (0.870 moles) 4Fe + 3O 2 2Fe 2 O 3 Example: How many grams of magnesium are required to produce 5.19 grams of silver in the reaction below? (0.585 grams Mg) Mg(s) + 2AgNO 3 (aq) Mg(NO 3 ) 2 (aq) + 2Ag(s) Example: When 1.45 g of Cu reacts with 3.14 grams of O 2, which species is completely used up?(cu) What is the limiting reactant?(cu) How many grams of CuO are produced?(1.82 g CuO) 2Cu + O 2 2CuO 11.) Know how to interpret chemical formulas. Example: How many moles of oxygen atoms are there in moles of aluminum nitrate, Al(NO 3 ) 3?(6.51 moles) 12.) Know how to predict the daughter nucleus in a nuclear equation. Example: What is the other product in the alpha decay of 238 U?( 234 Th) 13.) Know how to use half-lives of a radioactive substance to determine time for activity to decrease a given amount. Example: A specific isotope has a half-life of 15 minutes. How long will it take for the activity of this isotope to decrease from 32 millicuries to 8.0 millicuries?(30. minutes) 14.) Know the groups in the periodic table (Alkali metals, alkaline earth metals, halogens, noble gases). Example: Which of these is a halogen? Al, F, Na, Ca, Ne (F) 15.) Know how to calculate molarity. Example: A solution is prepared by dissolving grams of KCl in enough water to make 1,245 ml of solution. What is the molarity of the KCl in this solution?( M) 16.) Know how to find the molarity of an ion in a solution. Example: What is the molarity of C 2 H 3 O 2 - in a M solution of Sr(C 2 H 3 O 2 ) 2?(1.04 M) Page 2 of 6

3 17.) Know how to use the dilution equation. Example: How many ml of a 1.45 M solution of sucrose should be diluted to a final volume of 275 ml so that the resulting solution is M in sucrose?(42.3 ml) 18.) Know how to use mass/volume percent (m/v %). Example: How many grams of glucose are required to make 1.75 L of a 4.54% (m/v) solution of glucose? (79.5 g) 19.) Know your nomenclature. Example: What is the formula for vanadium(v) oxide? (V 2 O 5 ) Example: What is the formula for tin(ii) chloride dihydrate? (SnCl 2 2H 2 O) Example: What is the name for Sc 2 (SO 3 ) 3? (Scandium sulfite) 20.) Know the intermolecular forces and when they are present. Example: Which of the following pure substances exhibits hydrogen bonding? Dipole dipole forces? Induced dipole induced dipole forces? CH 2 F 2, CH 3 CH 2 NH 2, CH 2 O. (CH 3 CH 2 NH 2 :induced dipole induced dipole, dipole dipole, hydrogen bonding. CH 2 O: induced dipole induced dipole, dipole dipole. CH 2 F 2 : induced dipole induced dipole, dipole dipole) 21.) Know how to determine if a compound is ionic or molecular. Example: Which of these is an ionic compound, CaO or CF 4.(CaO) 22.) Know how to use specific heat capacity. Example: What mass of water can be heated from 15.0 o C to 73.5 o C with 2,398 cal of energy? Take the specific heat capacity of water as cal/g o C. (41.0 g) 23.) Know what it means for a process to be exothermic or endothermic. Example: When heat is produced in a chemical reaction, is the process exothermic or endothermic? (exothermic) Is the energy of the products higher or lower than that of the reactants? (Lower) 24.) Know how to use the ideal gas law. Example: What pressure is exerted by moles of N 2 gas at a temperature of 23.1 o C in a volume of 2.14 L? (3.57 atm) Page 3 of 6

4 25.) Know how to use the combined gas law. Example: If gas occupies a volume of 27.4 ml at a pressure of 2.55 atm, what volume will that gas occupy at a pressure of atm, assuming constant temperature and amount of gas?(92.1 ml) 26.) Know how to calculate the partial pressure of a gas. Example: There are moles of gas A and moles of gas B in a container. The total pressure in the container is atm. What is the partial pressure of gas A?(0.266 atm) 27.) Know how to find the mass number of an isotope. Example: What is the mass number of an isotope of silver (Ag) that contains 62 neutrons?(109) 28.) Know the types of bonds (non-polar covalent, polar covalent, ionic) and when they form. Example: What type of bond forms when calcium and fluorine combine to form a bond?(ionic) Carbon and fluorine?(polar covalent) Carbon and hydrogen? (non-polar covalent) 29.) Know how to predict relative bond polarities (based on relative electronegativity differences). Example: Which is a more polar bond, a N H bond or a N O bond?(n H) 30.) Know how to predict if a molecule is polar or not. Example: Which of the following molecules is polar? CH 3 F, CO 2, CCl 4 (CH 3 F) 31.) Know how to tell how many valence electrons there are in an atom. Example: How many valence electrons does germanium (Ge) have? (4) 32.) Know how to predict how many bonds an atom forms based on it s valence electrons. Example: Based on it s valence electrons, how many bonds will an oxygen atom typically form? (2) 33.) Know how to write electron configurations. Example: What is the complete electron configuration for elemental silicon, Si? (1s 2 2s 2 2p 6 3s 2 3p 2 ) Page 4 of 6

5 34.) Know how to tell how many electrons an ion has. Example: How many electrons are there in an atom of Cu 2+?(27) 35.) Know how to determine which species is oxidized and which is reduced in a single replacement reaction. Example: What species is reduced in the following reaction? (H + ) Mg(s) + 2HCl(aq) MgCl 2 (aq) + H 2 (g) 36.) Know how to find the conjugate acid and the conjugate base of a species. Example: What is the conjugate base of phosphoric acid, H 3 PO 4?(H 2 PO 4- ) 37.) Know the strong acids and strong bases. Example: Which of these is a strong base, RbOH or CH 3 CH 2 NH 2?(RbOH) 38.) Know about ph and [H + ]. Example: If the [H + ] in a solution is 1x10-8 M is the solution more or less acidic than a solution whose ph is 6.0?(Less) 39.) Know what affects the rate of a chemical reaction. Example: Which one will increase the rate of a chemical reaction, increasing the temperature of the reaction or agitating the reaction vessel? (Increasing the temperature) 40.) Know the colligative properties. Example: Which of the following does not change when a solute is added to some water, osmotic pressure or color? (color) 41.) Know how to find the charge on ions in an ionic compound. Example: What is the charge on the manganese ion in Mn 2 O 3?(+3) 42.) Know how to classify a reaction as combination, decomposition, single replacement, double replacement, or combustion. Example: What type of reaction is the following?(single replacement) Zn(s) + 2HCl(aq) ZnCl 2 (aq) + H 2 (g) 43.) Know how to write a net ionic equation. Example: Write the net ionic equation for the reaction of silver acetate with sodium chloride. ( Ag + (aq) + Cl - (aq) AgCl(s) ) Page 5 of 6

6 44.) Know how to write Lewis structures. Example: Draw the Lewis structure for ozone, O ) Know how to predict how many resonance forms a compound has. Example: How many resonance forms are there for the carbonate ion, CO 3 2-? (3) 46.) Know VSEPR theory (how to predict the shape of a molecule). Example: What is the shape of the SCl 2 molecule?(bent) 47.) Know Le Châtelier s principle. Example: What could you do to make sure that the following reaction goes toward completion (to the right)? Add HCN, Add H 2 O, remove H 3 O +, remove CN - ) HCN(aq) + H 2 O(l) H 3 O + (aq) + CN - (aq) Page 6 of 6

Final Exam Review Chem 101

Final Exam Review Chem 101 1. Know your nomenclature. a) Know how to go from the name to the formula. b) Know how to go from the formula to the name. 1. Ionic compounds (binary and ternary) a. Example: