Chapter 4: Balancing Equations
Balance the equation
CO2 (g) + CaSiO3 (s) + H2O (l) → SiO2 (s) + Ca(HCO3)2 (aq)
2 CO2 (g) + CaSiO3 (s) + H2O (l) --> SiO2 (s) + Ca(HCO3)2 (aq)
Balance the following equation and determine how many moles of O2 are required to react completely with 7.2 moles of C6H16
C6H16 (g) + O2 (g) ⟶ CO2 (g) + H2O (g)
72 mol O2
Calculate the molarity of the solution:
32.4 mol KCl in 50.0 L solution
0.648 M
Complete and balance the equation below (if no reaction occurs, write "NO REACTION"):
CrBr2 (aq) + Na2CO3 (aq) ⟶
CrBr2 (aq) + Na2CO3 (aq) ⟶ CrCO3 (s) + NaBr (aq)
What is pressure? What causes pressure?
Pressure is the force (Newton) exerted per unit area (m2) by gas molecules as they collide with the surfaces around them. A molecule exerts a force when it collides with a surface. The result of many of these collisions is pressure.
Balance the equation
Cu2O (s) + C (s) → Cu (s) + CO (g)
Cu2O (s) + C (s) --> 2 Cu (s) + CO (g)
If a plant consumes 37.8 g of CO2 in one week, what mass (in g) of glucose (C6H12O6) can the plant produce based on the reaction shown below?
6 CO2 (g) + 6 H2O (l) → C6H12O6 (aq)+ 6 O2 (g)
25.8 g C6H12O6
Calculate the molarity of the solution:
32.6 g KCl in 250 L solution
0.00175 M
Write a balanced molecular equation for the precipitation reaction that occurs (if any) when aqueous lithium sulfate and aqueous lead (II) acetate are mixed. If no reaction occurs, write “NO REACTION”
Li2SO4 (aq) + Pb(C2H3O2)2 (aq) → PbSO4 (s) + LiC2H3O2 (aq)
The pressure in Denver, Colorado (elevation 5280 ft), averages about 24.9 in Hg. Convert this pressure to each indicated unit.
atm (1 Hg = 0.0334211 atm)
mmHg (1 Hg = 25.4 mmHg)
psi (1 Hg = 0.491154 psi)
Pa (1 Hg = 3386.39 Pa)
0.832 atm
632 mmHg
12.2 psi
8.43 x 104 Pa
Balance the equation
Na2S (aq) + Cu(NO3)2 (aq) -> NaNO3 (aq) + CuS (s)
Na2S (aq) + Cu(NO3)2 (aq) → 2 NaNO3 (aq) + CuS (s)
Manganese (IV) oxide reacts with aluminum to form elemental manganese and aluminum oxide according to the reaction below. What mass of Al is required to completely react with 25.0 g MnO2?
3 MnO2 + 4 Al ⟶ 3 Mn + 2 Al2O3
10.3 g Al
If your original solution has a volume of 45.0 L and a molarity of 75.0 M, to what volume would you dilute to obtain a 15.0 M solution?
225 L
Write balanced complete ionic and net ionic equations for the following reaction:
Na3PO4 (aq) + NiCl2 (aq) ⟶ Ni(PO4)2 (s) + NaCl (aq)
Complete: 6 Na+ (aq) + 2 PO43- (aq) + 3 Ni2+ (aq) + 6 Cl- (aq) → Ni3(PO4)2 (s) + 6 Na+ (aq) + 6 Cl- (aq)
Net: 3 Ni2+ (aq)+ 2 PO43- (aq) → Ni3(PO4)2 (s)
A sample of gas has an initial volume of 4.20 L at a pressure of 755 mmHg. If the volume of the gas is increased to 7.10 L (at constant temperature), what is its pressure?
447 mmHg
Solid sodium is added to liquid water and reacts to produce hydrogen gas and aqueous sodium hydroxide. Write a balanced chemical equation for this reaction.
2 Na (s) + 2 H2O(l) ⟶ H2 (g) + 2 NaOH (aq)
Sodium and chlorine react to form sodium chloride according to the reaction below. What is the theoretical yield (in grams) of sodium chloride for the reaction of 55.0 g Na with 67.2 g Cl2?
2 Na (s)+ Cl2 (g) ⟶ 2 NaCl(s)
111 g NaCl
Given the following reaction, what volume (in mL) of 0.131 M CCl4 is required to react completely with 52.0 mL of 0.453 M SbF3?
3 CCl4 + 2 SbF3 → 3 CCl2F2+ 2 SbCl3
270 mL
Write balanced molecular and net ionic equations for the reaction between hydrochloric acid and rubidium hydroxide.
Molecular: HCl (aq) + RbOH (aq) → H2O (l) + RbCl (aq)
Net: H+ (aq) + OH- (aq) → H2O (l)
What volume is occupied by 0.118 mol of helium gas at a pressure of 0.97 atm and a temperature of 305 °K? Would the volume be different if the gas was argon (under the same conditions)?
3.0 L
The volume would not be different if the gas was argon.
Write the balanced equation for the combustion of erythritol (C4H10O4)
2 C4H10O4 (s) + 9 O2 (g) → 8 CO2 (g) + 10 H2O (g)
Determine the limiting reactant, theoretical yield, percent yield, and amount of excess reactant from the reaction below with 5.6 g Cr2O3, 9.5 g Al, and 1.62 g Cr.
Cr2O3 (s) + Al (l) → Cr (l) + Al2O3 (s)
Limiting Reactant = Cr2O3
Theoretical Yield = 3.83 g
Percent Yield = 42.3%
Excess = 7.51 g Al
Determine whether each compound is soluble or insoluble. If the compound is soluble, list the ions present in solution.
AgNO3
Pb(C2H3O2)2
KNO3
(NH4)2S
Soluble, Ag+ and NO3-
Soluble, Pb2+ and 2 C2H3O2-
Soluble, K+ and NO3-
Soluble, 2 NH4+ and S2-
For the following reaction:
Fe2O3 (s) + H2 (g) → Fe (s) + H2O (l)
What are the oxidation states for each element?
What element is oxidized?
What element is reduced?
What is the oxidizing agent?
What is the reducing agent?
Fe2: +3, O3: 2-, H2: 0, Fe: 0, H2 (of H2O): +1, O: 2-
Oxidized: H
Reduced: Fe
Oxidizing Agent: Fe
Reducing Agent: H
A piece of dry ice (solid carbon dioxide) with a mass of 22.1 g sublimes (converts from solid to gas) into a large balloon. Assuming that all of the carbon dioxide ends up in the balloon, what is the volume of the balloon at 22 °C and a pressure of 742 mmHg (1 atm =760 mmHg)?
12.5 L