4: Chemical Reactions/Aqueous Solutions
T/F: Water is produced in the following reaction:
CaCO3(s) + HCl(aq) ->
True
Which substance is present in the largest proportion in a solution?
a) solute b) salute c) gas d) solid e) solvent
e) solvent
A 40.0 g bullet exits the barrel of a gun at a velocity of 925 m/s. Determine the bullet’s kinetic energy.
a) 3.7x104 J
b) 1.71x104 J
c) 1.85x104 J
d) 3.42x107 J
e) 1.71x107 J
b) 1.71x104 J
The reaction between aluminum and iron(III) oxide is known as a thermite reaction and produces enough heat to melt the iron (melting point 1530°C). This reaction
a) is not a redox b) produces gas c) is endothermic d) is exothermic e) is a decomposition
d) is exothermic
What are the units for J, joules?
a) m/s b) g·m/s c) kg·m2/s2 d) kg·m/s
e) g·m/min
c) kg·m2/s2
What is the coefficient of CO2 when the following combustion equation is properly balanced?
___ C2H4 + ___ O2 → ___ CO2 + ___ H2O
2
What mass of hydrogen gas can be produced by reacting 6.0 mol of aluminum with excess HCl?
18 g H2
2 Al(s) + 6HCl(aq) -> 2AlCl3(aq) + 3H2(g) Type of rxn? SD
6.0 mol Al X 3 mol H2/2 mol Al X 2.02 g H2/1mol H2= 18 g H2
The surroundings do 2.51 kJ of work on a chemical reaction and the reaction absorbs 1820 J of heat from
the surroundings. Determine change in internal energy (delta U)
a) 1823 kJ
b) 1823 J
c) 4330 J
d) 0.6902 kJ
e) -4.33 kJ
c) 4330 J
In the balanced single displacement reaction of 2Al(s) + Fe2O3(s) →
How many electrons were transferred?
a) 0 b) 1 c) 3 d) 6 e) 12
d) 6
What is the molarity of 250 mL of a solution containing 7.5 g of sodium chloride? NaCl (58.44)
a) 0.51 M
b) 30 M
c) 0.032 M
d) 1.95 M
e) 7.5 M
a) 0.51 M
What are the spectator ions in the neutralization reaction below?
KOH(aq) + HCl(aq) ->
a) K+ and OH-
b) H+ and Cl-
c) K+ and Cl-
d) H+ and OH-
e) K+ only
c) K+ and Cl-
You have a solution that is 1.5 M H2SO4.
How many milliliters of this acid do you need to prepare 100.0 mL of 0.18 M H2SO4?
12 mL
. Determine DH°rxn for the combustion of C6H6: C6H6(l) + 15/2O2(g) -> 6CO2(g) + 3H2O(g)
Standard enthalpy of formation delta H°ƒ in kJ/mol: C6H6(l)= -49;
O2(g)= 0;
CO2(g)= -393.5;
H2O(g)= -241.8.
a) +684 kJ
b) +586 kJ
c) -684 kJ
d) -3037 kJ
e) -3135 kJ
e) -3135 kJ
Is potassium sulfate soluble in water?
a) Impossible to determine
b) No
c) Yes
Christina calculated the theoretical yield of her product to be 0.625 g.
After running the experiment, she made 0.499 g of product in the lab. What was her percent yield?
a) 125%
b) 62.5%
c) 20.2%
d) 79.8%
e) 50.0%
d) 79.8%
e precipitate formed in the reaction of aqueous iron(III) nitrate and aqueous lithium hydroxide is:
___Fe(NO3)3(aq) + ___LiOH(aq) ->
a) FeOH
b) FeLi
c) LiNO3
d) Fe3OH
e) Fe(OH)3
e) Fe(OH)3
How many grams of silver bromide can be formed when solutions containing
50.0 g MgBr2 and 100.0 g of AgNO3 are mixed?
How many grams of the excess reagent remain unreacted?
Molar Masses of Reactants:
MgBr2=184.11 g/mol
AgNO3=169.91 g/mol
(Hint: First solve for how much AgNO3 is needed, and subtract from how much is present.)
answer=7.7g AgNO3
Step 1: Find limiting reactant by calculating how much product each reagent can form (AgBr is limiting)
Step 2: Solve how much AgNO3 is used in the reaction.
MgBr2->AgNO3
Step 3: Subtract amount of AgNO3 present-AgNO3 used
100.0g AgNO3-92.3g AgNO3= 7.7g AgNO3
Determine the amount of heat released when 0.2430 mol C8H18 reacts with excess O2.
2C8H18(g) + 25O2(g) -> 16CO2(g) + 18H2O(g);
delta H= -10,942 kJ
a) -10,942 kJ
b) -5471 kJ
c) -1329 kJ
d) -2659 kJ
e) -3371 kJ
c) -1329 kJ
If 5.13 g ammonia gas reacts with 3.15 g of oxygen gas to form nitrogen monoxide and water, what is the excess reagent?
N(14.01), H(1.01), O(16.00)
a) there is none
b) H2O
c) NO
d) O2
e) NH3
4NH3(g) + 5O2(g) ⟶ 4NO(g) + 6H2O(g)
e) NH3
What is the oxidation number of carbon in the carbonate ion?
a) +3
b) +2
c) +4
d) +1
e) +5
c) +4
Which one of the following reactions does not proceed as written (there is no reaction)?
a) Mg(s) + HCl(aq) ->
b) Zn(s) + HCl(aq) ->
c) Cu(s) + HCl(aq) ->
d) Na(s) + HCl(aq) ->
e) Fe(s) + HCl(aq) ->
Activity Series:
Increasing ease of oxidation:
Na > Mg> Zn> Fe> H> Cu
c) Cu(s) + HCl(aq)
How many milliliters of 0.150 M H2SO4 are required to react with 4.10 g NaHCO3 (sodium hydrogen carbonate or sodium bicarbonate)? What type of reaction is it?
163 mL, Acid-Base w gas formation (DD)
33 mL sample of 1.20 M HCl is added to 67 mL excess NaOH in a coffee cup calorimeter.
Solution temperature rose from 25.0°C to 31.8°C. Give enthalpy change, delta H, for rxn.
HCl(aq) + NaOH(aq) -> NaCl(aq) + H2O(l); delta H = ? kJ/mol
Assume specific heat & density of final solution are those of water.
Assume total volume of solution = HCl + NaOH volumes.
a) -54 kJ/mol
b) -71.8 kJ/mol
c) -71,800 kJ/mol
d) -263 kJ/mol
e) -2.84 kJ/mol
b) -71.8 kJ/mol
Write the formulas for the following: Iron (II) Carbonate, Ammonium Phosphate, and Acetic acid
FeCO3, (NH4)3PO4, HC2H3O2