Download CP Chemistry Midterm Study Guide

Chemistry Midterm Study Guide
Spring 2012
1. What types of properties are dependent upon the particles in a solution?
2. What is the % composition of oxygen in CO2?
3. Which part of the solution (solute or solvent) is water in an aqueous solution?
4. What is a precipitate?
5. Name and describe three types of mixtures.
6. Could you add more sugar to an unsaturated Kool Aid solution?
7. What type of chemical reaction produces heat?
8. In the following chemical reaction, how many moles of oxygen are needed to produce 10 moles of
water?
2 H2 + 1 O2  2 H2O
9. If salt is added to water, will the electrical conductivity of the water increase or decrease?
10. What three factors increase the solubility of a solid?
11. Define the term solvation.
12. As solute is added to a solution, what happens to the boiling point, melting point, vapor pressure,
and the osmotic pressure of the solution?
13. What is the solute in a sugar water solution?
14. If water and alcohol are miscible, what are two liquids that are immiscible?
15. What is the molarity of a solution containing 90 grams of C6H12O6 in 1 liter of water?
16. How many grams of H2O can be produced in the following reaction with 10 grams of oxygen?
H2 + O2  H2O
17. What will polar solvents dissolve?
Use the solubility curve for questions 18-19
18. According to the graph, 50 g of KNO3
dissolved in 100g of H2O at 20oC would be a
____________ solution. (saturated,
unsaturated, supersaturated)
19. According to the graph, at what
temperature will 30 grams of KClO3 form a
saturated solution in 100g of H2O?
20. What is the solution concentration of 25 g of
NaCl mixed in 50 g of H2O?
21. How many grams of MgCl2 are in 500 mL of
a 3.2 M solution?
22. How many atoms of sulfur do you have if you
have 4 moles?
23. Convert 500 grams of magnesium to moles.
24. If we have 6.02x1023 molecules of oxygen,
how many moles do we have?
25. One mole of carbon (C) atoms contains ________________ atoms.
26. Convert 4 moles of (NH4)2SO3 to grams.
27. How many grams of oxygen are in 2 moles of Mg3(PO4)2?
28. What do the coefficients in a chemical equation represent?
29. How many grams of chlorine atoms are present in 4 moles?
30. What is the molar mass of Mg3(PO4)2?
31. The smaller numbers used to write a chemical formula is called ___________ (ex: the two in MgCl2)
32. A compound contains 49.98 grams of carbon and 10.47 grams of hydrogen. The molar mass of the
compound is 87 g/mol. Determine the molecular formula.
33. Avogadro's number is ____________.
34. A substance made in a chemical reaction is called ____________________.
35. What is the S.I. unit for each of the following?
Mass
________
Molar Mass ________
Volume
________
Molarity
________
36. Balance the following reactions:
Ca + H2O  Ca(OH)2 + H2
P4O10 + H2O  H3PO4
Fe + Cl2  FeCl3
CH4 + O2  CO2 + H2O
Fe + Ag(NO2)2  Fe(NO2)3 + Ag
C6H12O6 + O2  CO2 + H2O
Use the following information for questions 37 & 38:
Ammonium nitrate (NH4NO3) is an important fertilizer and is also used in the manufacture
of explosives and fireworks. It is produced by treating nitric acid (HNO3) with ammonia gas
(NH3). The balanced equation for this reaction is:
HNO3 + NH3  NH4NO3
37. If 6 moles of ammonia gas are used with 4 moles of nitric acid for the reaction, what is the limiting
reactant?
38. How many moles of ammonium nitrate would you make from the ingredients in the problem above?
39. Define the following terms:
a. reactant
g. law of conservation of mass
b. product
h. stoichiometry
c. limiting reactant
i. mole
d. excess reactant
j. molar mass
e. empirical formula
k. molecular mass
f. molecular formula
40. Match the correct definition to the formula that it represents;
____H2O2
a. empirical formula
____H2O
b. molecular formula
____C6H12O6
c. hydrate
____CH2O
____CuSO4▪ 5H2O
41. How does the total mass of the reactants compare to the total mass of the products in a chemical
reaction? This is true according to what law? (Hint: to satisfy this law we balance chemical
reactions)
42. What is the % of carbon in CO2?
43. a. A 32.8 gram sample of a compound contains 2.00 g of carbon, 22.8 g of barium and 8.00 g of
oxygen, what is its empirical formula?
b. What is the empirical formula for monosodium glutamate (MSG) if it is composed of
35.5% C, 4.77% H, 8.29% N,13.6% Na and 37.9% O?
44. What is the molecular formula for a compound with an empirical formula of NO2 and a molecular
mass of 92.0 g?
44. The following equation shows the formation of aluminum oxide: 4 Al + 3 O2 --> 2 Al2O3
How many grams of aluminum are needed to produce 250 g of aluminum oxide?
45. Identify the type of bond in each of the following (ionic, polar covalent, non-polar covalent):
NaCl
CO
HCl
H2O
46. If 0.55 g of a gas dissolves in 1.0 L of water at 20.0 atm of pressure, how much will dissolve at
110.0 atm of pressure?
48. In the reaction between calcium hydride and water, the theoretical yield of hydrogen gas from
75.0 grams of calcium hydride is 7.18 grams. In running this reaction, the actual amount of
hydrogen produced was 6.94 grams. What was the percent yield of this reaction?
Answers:
1. Colligative
2. 72.7%
3. Solvent
4. Solid that settles to the bottom in a chemical reaction
5. Solutions (clear, homogeneous, cannot be filtered, do not exhibit the Tyndall Effect);
Colloid (cloudy, heterogeneous, cannot be filtered, do exhibit the Tyndall Effect);
Suspensions (cloudy, heterogeneous, can be filtered, do exhibit the Tyndall Effect)
6. Yes
7. Exothermic
8. 5 moles
9. Increase
10. Increase temperature, agitate, decrease particle size
11. Process of a solute breaking apart in a solvent
12. B.P. Increases, M.P. decreases, V. P. Decreases, O.P. Decreases
13. The sugar
14. Oil and water
15. .5 M
16. 11.25 g
17. Polar and ionic solutes
18. Supersaturated
19. 71°C
20. 33%
21. 150.4 g
22. 2.408x1024 atoms
23. 20.83 moles
24. 1 mole
25. 6.02x1023 atoms
26. 464 g
27. 16 g
28. Number of moles of each substance
29. 280 g
30. 264 g/mol
31. subscripts
32. C6H15
33. 6.02x1023
34. product
35. grams; cm3 or liters; grams/mole; moles/liter
36. a. 1,4,1,1 b.1,6,4 c. 2,3,2 d.1,2,1,2 e. 2,3,2,3 f. 1,6,6,6
37. HNO3
38. 4 mol
39. a. left of the yield sign
b. formed in a chemical reaction
c. reactant that is used up in a chemical reaction, limits the amount of product produced
d. reactat left over after a chemical reaction is over
e. reduced chemical formula
f. How chemicals actually bond to make a molecule or formula unit
g. the total mass or energy of the reactants = the mass or energy of the products
h. quantitative analysis to calculate the relationships of reactants and products in a
chemical reaction
i. unit for the number of particles in a substance, Avogadro’s number, 6.02 x 1023
j. the mass of 1 mole of a substance in grams
k. the mass of a molecule in atomic mass units
40. b, a and b, b, a, c
41. equal, Law of Conservation of Mass
42. 27%
43.BaCO3
44. N2O4
45. 132 grams Al
46. 3.0 g/L
48. 96.7%