CHM 130
Dr. Debbie
HW #2b
Due Wednesday, March 26th, 2014
Names: __KEY________________________
Chapters 7, 16, and 8
1. Write the products if none are given, label the states for each reactant and product if not given, then
balance the reaction and finally classify each reaction type as combination (C), decomposition (D),
single replacement (SR), double replacement (DR), combustion (CB) or acid base neutralization (N).
a. __D__ type
b. __SR__ type
c. __NR__ type
d. __CB__ type
_2__H2O2 (l)  _2__H2O (__l_) + ___1_O2 (__g__)
____Mg(NO3)2 (__aq__) + 2 Na (__s__)  2 NaNO3 (aq) + Mg (s)
AlCl3( _aq_ ) + Au(__s __)  no reaction
____CH4(g) + ___2_O2(___g_)  CO2(g) + 2 H2O(g)
e. __C__ type
____ Ca(_s__) + ____ Cl2 (__g__)  ____CaCl2 (s)
f. __N__ type
____HCl(aq) + ____KOH(aq)  HOH(l) + KCl(aq)
g. ___NR_ type
____ Fe(____) + ____H2O (____)  No reaction
2. Which of the following metals will react with water? Circle all that apply.
a. Sr
3.
b. Al
c. Ag
d. Na
e. Ni
Assign oxidation numbers to the elements in the reaction below and determine what is oxidized,
reduced, the oxidizing agent, and the reducing agent. The equation is already balanced.
Co (s) + Pb2+(aq)  Pb (s) + Co2+(aq)
oxidized: __Co(s)____
reduced: __Pb2+(aq)____
oxidizing agent: __Pb2+(aq)____
reducing agent: __Co(s)_____
4. Which one of these chemicals is insoluble in water?
a. Cu(NO3)3
b. Al(C2H3O2)
c. Na3PO4
d. AgBr
e. BaCl2
5. What three things can be done to increase the number of successful collisions in a reaction?
a. ____increase the number of collisions_________________
b. ____supply enough energy (activation energy)__________
c. ____orient molecules correctly to create products________
CHM 130
Spring 2014
Hmwk 2b
6. What three changes can be made to increase the rate of a reaction?
a. ____increase the concentrations of reactants____________
b. ____increase the temperature of reaction_______________
c. ____add a catalyst_________________________________
7. Define activation energy: the minimum amount of energy needed to convert reactants into
products (to form the transition state)
8. In the energy profile below, label the activation energy (Ea) and the overall energy change of the
reaction (H). Is this reaction endothermic or exothermic? ___exothermic________
Ea
H
9. How many molecules are in 39.95 grams of gaseous argon? __6.02 x 1023 atoms ___
10. How many atoms are in 1.98 moles of copper?
1.98 moles Cu * (6.02 x 1023 atoms / 1 mol) = 1.19 x 1024 atoms Cu
11. How many moles are in 4.15 x 1025 atoms of neon?
4.15 x 1025 molecules Ne * (1 mol / 6.02 x 1023 molecules) = 68.9 moles of Ne
12. What is the molar mass of iron (III) hydroxide?
Fe(OH)3 
1 x Fe = 55.85; 3 x O = 3 x 16.00; 3 x H = 3 x 1.01
106.9 g/mol
13. How many grams are in 7.54 moles of iron (III) hydroxide?
7.54 mol Fe(OH)3 * (106.9 g / 1 mol) = 806 g Fe(OH)3
CHM 130
Spring 2014
Hmwk 2b
14. How many atoms are in 1.30 grams of carbon?
1.30 g C * (1 mol / 12.01 g) * (6.02 x 1023 atoms / 1 mol) = 6.52 x 1022 atoms C
15. What is the volume of 4.53 moles of gas at STP?
4.52 mol * (22.4 L / 1 mol) = 101 L
16. How many liters at STP would 1.08 grams of carbon dioxide occupy?
1.08 g CO2 * ( 1 mol / 44.01 g) * ( 22.4 L / 1 mol) = 0.550 L
17. What is the density of carbon monoxide gas at STP?
Molar mass / molar volume = (28.01 g/mol CO) / (22.4 L/mol) = 1.25 g/L
CHM 130
Spring 2014
Hmwk 2b