Chemistry Level 3, L4 Midterm Exam : Pre Exam directions : Jan 2014

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1 Chemistry Level 3, L4 Midterm Exam : Pre Exam directions : Jan 2014! The Chemistry Level 3 & 4 Midterm exam requires you to conduct research by looking up data on various charts and tables. You will then be interpreting data in questions using this information. You must be sure you find each of the following BEFORE you come in to take the exam! If you cannot find one of them, go to the chemistry web site and you will find the handouts to download. or directly to the Download Center: BRING YOUR BOOK to the exam to be checked, a **Scientific calculator (exponents) and a PENCIL!! Your self prepared study guides from each chapter from first semester :! Conversions! Percent composition, empirical formulas! Matter, energy and changes! Balancing Equations, predicting products! Atoms and nuclear chemistry! Stoichiometry! Chemical names and formulas! Electrons and light! Grams and moles and conversions! Periodic Law You may also use the charts and Handouts from the semester!! Periodic Table of the Elements! Solubility chart and Activity Series! Metric conversion Table, Mole Traffic Circle! Wave Paper! Vocabulary from Matter, energy and change! Representative elements (periodic table)! Vocabulary from Atoms and nuclear chemistry! Formula writing paper (or small Polyatomic ion chart) Chemistry L3: Mid term review Questions 1. Write the electron configurations for Na, Na +, Cl, Cl and Kr. Which ones are happy? 2. a. Classify each of the following changes as Physical, Chemical, Nuclear. Specify the type of chemical change and nuclear change.! b. Classify the product in each case as : element, compound, heterogeneous mixture or homogeneous mixture. A. Some purple Iodine crystals and Sodium metal are put in a dish. The dish becomes very hot. The only product is a white crystalline solid. B. Some purple Iodine-131 is put in a dish in a sealed container. 30 days later some of the Iodine-131 is gone and some Xenon-131 gas is found in the container. C. Some purple Iodine crystals are mixed with some liquid alcohol. Result is a purple, clear liquid. 3. Refer to your handout from Unit 2 (Matter, Energy and changes). Which picture of particles would represent : I 2, Na, NaI, H 2 O Answers: 1. Na + = [Ne], Cl = [Ar], others on per table; happy=na +, Cl, Kr ; 2. A= chem, combin., compound ; B = nuclear, beta minus decay, element; C = phys, dissolving, homo mix; 3. I 2 = Diatomic ele., Na = ele, NaI = Ionic Comp, H 2 O = molec. comp

2 Chemistry Level 3,4 Midterm Review Crossword puzzle Across 4. The name of NCl 3 (2 wds) 9. Has mass and occupies space. 10. A bundle of light energy 13. The only solid diatomic element 14. Has electron config. [Xe] 6s 2 4f 14 5d 10 6p Can be separated by chemical, but not physical, means; has a definite formula 17. The name for SO This element has 10 electrons 20. Type of element that is brittle, non-conductor 22. Nickel and copper are used to manufacture these objects which you bring to a store 23. Color change, heat and solid precipitate often indicate a change. 24. The lightest subatomic particle 27. Outer electron config. of the noble gases 28. Heat, light, electricity are examples of 30. Element produced by this alpha decay: 210 Po > 4 He +???! 84! A nuclear change in which 2 small atoms become one larger atom Down 1. An excited electron gives off energy as 2. Number of outer electrons in arsenic 3. Element with 15 protons and 16 neutrons 5. Has outer electron configuration of 5s 2 5p 2 6. Mass number of 7 Li 7. The name for S This element has a radioactive isotope with a mass number 40 and 21 neutrons 11. Sand in water is a mixture. 12. Dissolving salt in water is a change 13. The name of FeBr 2. (2 wds, trick question). 15. Type of reaction: 2K + Cl 2 - -> 2KCl 16.! A replacement reaction only occurs if an Insoluble solid, gas or water forms 18. Add baking soda to neutralize an 21. Neptunium and Curium are elements 23.! Element with Atomic number Number of protons in Sodium 26. Biggest atom in sixth series 29. Number of energy levels occupied in Bismuth

3 Chemistry L3: Mid term review Problems 1-4 are review for the lab practical part of the exam. Do them first! (All ans on back!) *1. In an experiment, the Volume of a piece of Zinc is 4.5 ml and its mass is grams.! a. Calculate the experimental Density of the Zinc. How many sig figs should be in your Density?!! b. Calculate your % error. c. Is your measurement acceptable? Why or why not?! *2. 25 pieces of Lead shot have a mass of 1.23 g. a. What is the average mass of 1 lead shot?! b. Convert the mass of 1 lead shot to nanograms.! c. How many lead atoms are in 1 lead shot? *3. How much heat is absorbed by 20.0 g of Al heated from 15.0 C to 20.0 C? *4. You heat 4.00 g NaHCO 3 in an evaporating dish (empty mass of g) to decompose it into solid Sodium carbonate, gaseous water and gaseous carbon dioxide. After heating, the mass of the evaporating dish + the solid product is g. Fill in the Data Table. Calculate the mass of the solid product made in the experiment. Mass of evap dish Mass NaHCO 3 Mass of evap. dish + solid product Mass solid product Mass, g # sig figs 5. Classify these compounds as Ionic or Molecular. Name these compounds. a. CuSO 4! c. SO 2! b. MnCl 3! d. Co(NO 3 ) 2 6. a. You analyze a food additive and find it contains 4.17 g C, g H and 3.25 g N. What is the % composition by mass of this compound?! b. What is the Empirical formula for this compound?

4 7. Write the balanced, formula equation for these reactions. Includes states (s, l, g, aq)! What type of reaction are they? Does each react? Why or why not? a. Zinc metal + Silver Nitrate > b. Sodium sulfate + Calcium chloride > 8. a. Balance this equation. What type is it? Na + O 2 > Na 2 O! b g Na reacts with 3.40 L of O 2 gas at STP. How many grams of Na 2 O could be made from 10.4 g Na?! c. How many grams of Na 2 O could be made from 3.40 L of O 2 gas at STP?! d. What is the limiting reactant? Why?! e. How many grams of Na 2 O are actually made in the reaction? 9a. Write the Balanced equation for the complete combustion of C 5 H 10 gas. b. How many grams of C 5 H 10 would react with 78.0 Liters of O 2 gas at STP? 10. How many protons electrons and neutrons are in 18 O? 11. Check your Atoms handout. Which of the following radioactive isotopes has the longest half life? The shortest? 24 Na, 32 P, 90 Sr 12a. What is the frequency and energy of a photon of EM radiation with wavelength = 7.00 x 10 7 m? b. What part of the EM spectrum is this radiation? Answers: 1a. 7.5 g/ml, 2 sig figs, only 2 SF in Volume, b. 5.2%; c. yes ; 2a g, b x 10 7 ng, c x atoms; 3. C p Al=0.90 J/g C, on Per Table, Q = 90 J ; 4. 4 SF, 3 SF, 4 SF, 2.36 g made, 3 SF; 5. a. I, Copper(II) sulfate, b. I, Manganese(III) chloride; c. M, Sulfur Dioxide; d. I, Cobalt(II) Nitrate; 6. a % C, 7.25 % H, 40.6 % N; b. C 3 H 5 N 2 ; 7a. SR, Zn(s) + 2 AgNO 3 (aq) >2 Ag(s) +Zn(NO 3 ) 2 (aq), yes, Zn more active than Ag; 3b. DR, Na 2 SO 4 (aq) + CaCl 2 (aq) > CaSO 4 (s) + 2 NaCl(aq), Yes, CaSO 4 is Ins ; 8a. 4 Na + O 2 > 2 Na 2 O, Combination, b g Na 2 O from Na, c g Na 2 O from O 2, d. Na = LR, makes less product; e g Na 2 O made; 9a. 2 C 5 H O 2 > 10 H 2 O + 10 CO 2 ; b g C 5 H 10 ; p, 8 e, 10 n; 11. long= 90 Sr, short = 24 Na; 12a x sec -1, 2.84 x J, b. red light

ACP Chemistry (821) - Mid-Year Review

ACP Chemistry (821) - Mid-Year Review *Be sure you understand the concepts involved in each question. Do not simply memorize facts!* 1. What is chemistry? Chapter 1: Chemistry 2. What is the difference