1) A reaction which forms a solid product is an example of a(n):
A) oxidation-reduction reaction.
B) combustion reaction.
C) precipitation reaction.
D) gas evolution reaction.
E) none of the above
2) When water is heated, bubbles form in the water. Is this evidence of a chemical reaction? Why?
A) No, boiling water is a physical change.
B) Yes, the formation of a gas is evidence of a chemical reaction.
C) No, the formation of gas bubbles is a secondary chemical reaction which is ignored.
D) Yes, the formation of a gas is proof a new compound has been made.
E) none of the above
3) When the equation, ___N2 + ___H2 → ___NH3 is balanced, the coefficient of hydrogen is:
A) 1
B) 2
C) 3
D) 4
E) none of the above
4) What are the coefficients for the following reaction when it is properly balanced?
___Na3PO4 + ___Ba(NO3)2 → ___NaNO3 + ___Ba3(PO4)2
A) 2, 1, 1, 3
B) 2, 3, 1, 6
C) 2, 3, 6, 1
D) 6, 1, 3, 2
E) none of the above
5) Sodium metal reacts with water to form aqueous sodium hydroxide and hydrogen gas. Which equation below best describes the balanced equation for this reaction?
A) Na + H2O → NaOH (aq) + H (g)
B) S + H2O → SOH (aq) + H (g)
C) Na + H2O → NaOH (aq) + H2 (g)
D) 2Na + 2H2O → 2NaOH (aq) + H2 (g)
E) 2Na + H2O → Na2OH (aq) + H (g)
6) Which of the following compounds is INSOLUBLE?
A) potassium acetate
B) lithium carbonate
C) magnesium bromide
D) aluminum sulfide
E) none of the above
7) Which of the following compounds is SOLUBLE?
A) aluminum hydroxide
B) aluminum sulfide
C) aluminum carbonate
D) aluminum sulfate
E) none of the above
8) Which of the following is TRUE?
A) Stoichiometry shows the numerical relationship between chemical quantities in a balanced chemical equation.
B) Stoichiometry allows prediction of the amounts of products that form in a chemical reaction based on the amounts of reactants.
C) Stoichiometry allows prediction of how much of the reactants are necessary to form a given amount of product.
D) All of the above are true.
E) None of the above are true.
9) How many eggs are needed to make 1 dozen waffles, assuming you have enough of all other ingredients?
Given: 2 cups flour + 3 eggs + 1 tbs oil → 4 waffles
A) 48
B) 9
C) 12
D) 16
E) not enough information
10) How many moles of water are made from complete reaction of 1.4 moles of hydrogen gas?
Given the reaction: 2H2 + O2 → 2H2O
A) 2.8
B) 0.7
C) 1.4
D) 2.1
E) not enough information
11) How many moles of sodium metal are needed to make 3.6 moles of sodium chloride?
Given the reaction: 2Na + Cl2 → 2NaCl
A) 0.9
B) 7.2
C) 1.8
D) 3.6
E) not enough information
12) How many grams of water are made from the reaction of 4.0 grams of hydrogen gas?
Given the reaction: 2H2 + O2 → 2H2O
A) 18
B) 72
C) 36
D) 4.5
E) not enough information
13) How many grams of sodium metal are needed to make 29.3 grams of sodium chloride?
Given the reaction: 2Na + Cl2 → 2NaCl
A) 46.0
B) 5.75
C) 23.0
D) 11.5
E) not enough information
14) Determine the theoretical yield of C when 3 units of A and 10 units of B are reacted in the following generic chemical equation: 2A + 5B → 4C.
A) 3
B) 4
C) 6
D) 8
E) none of the above
15) What is the limiting reactant for the following reaction given we have 3.4 moles of Ca(NO3)2 and 2.4 moles of Li3PO4?
Reaction: 3Ca(NO3)2 + 2Li3PO4 → 6LiNO3 + Ca3(PO4)2
A) Ca(NO3)2
B) Li3PO4
C) LiNO3
D) Ca3(PO4)2
E) not enough information
16) The initial volume of a gas cylinder is 750.0 mL. If the pressure of a gas inside the cylinder changes from to , what is the final volume the gas occupies?
A) 3.151 L
B) 630.0 mL
C) 1.750 L
D) 321.4 mL
E) none of the above
17) When must temperature values in gas law calculations be expressed in kelvin units?
A) only for Charles's law
B) only for the Ideal Gas law
C) only for the Combined Gas law
D) never
E) always
18) What is the final volume of a balloon that was initially 500.0 mL at 25°C and was then heated to 50°C?
A) 461 mL
B) 193 mL
C) 1.00 L
D) 542 mL
E) none of the above
19) A balloon originally had a volume of 0.439 L at 44°C and a pressure of 729 torr. To what temperature must the balloon be cooled to reduce its volume to 378 mL if the pressure remained constant?
A) 0°C
B) 38°C
C) 95°C
D) 273°C
E) none of the above
20) A sample of helium gas initially at 37.0°C, 785 torr and was heated to 58.0°C while the volume expanded to . What is the final pressure in atm?
A) 517
B) 0.681
C) 1.79
D) 3.21
E) none of the above
21). If 10.0 grams of aluminum oxide were actually produced, what is the percent yield of the reaction below given that you start with 15.0 g of Al and 18.0 grams of O2?
Reaction: Al + O2 → Al2O3 balance the reaction
22). A big balloon of H2 has a volume of 3.20 x 104 L, T is 20.0°C, P = 750.0 torr. How many moles of gas are in the balloon?
Answers: 1-5 CACCD 6-10 DDDBC 11-15 DCDCA 16-20 CEDAB