1. Solutions in Chemical Reactions
Chapter Solutions
12.6
Solutions in Chemical Reactions
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Publishing as Benjamin Cummings

2. Molarity in Chemical Reactions
In a chemical reaction,
The volume and molarity of a solution are used to determine the moles of a reactant or product.
volume (L) x molarity ( mol ) = moles
1 L
If molarity (mol/L) and moles are given, the volume (L) can be determined
mol x L = volume (L)
mol

3. Using Molarity of Reactants
How many mL of 3.00 M HCl are needed to react
4.85 g CaCO3?
2HCl(aq) + CaCO3(s) CaCl2(aq) + CO2(g) + H2O(l)
STEP 1 Given M HCl; 4.85 g CaCO3
Need volume in mL
STEP 2 Plan
g CaCO mol CaCO mol HCl mL HCl

4. Using Molarity of Reactants (cont.)
2HCl(aq) + CaCO3(s) CaCl2(aq) + CO2(g) + H2O(l)
STEP 3 Equalitites
1 mol CaCO3 = g; 1 mol CaCO3 = 2 mol HCl
1000 mL HCl = 3.00 mol HCl
STEP 4 Set Up
4.85 g CaCO3 x 1 mol CaCO3 x 2 mol HCl x 1000 mL HCl
g CaCO mol CaCO mol HCl
= mL HCl required

5. Learning Check How many mL of a 0.150 M Na2S solution are
needed to react 18.5 mL of M NiCl2 solution?
NiCl2(aq) + Na2S(aq) NiS(s) + 2NaClaq)
1) mL
2) mL
3) mL

6. Solution 3) 27.8 mL 0.0185 L x 0.225 mol NiCl2 x 1 mol Na2S x 1000 mL
1 L mol NiCl mol
= mL Na2S solution

7. Learning Check What is the molarity if 15.0 mL of AgNO3 solution
reacts with 22.8 mL of M MgCl2?
MgCl2(aq) + 2AgNO3(aq) AgCl(s) + Mg(NO3)2(aq)
1) M
2) M
3) M

8. Solution
3) M AgNO3
L x mol MgCl2 x 2 mol AgNO3 x =
1 L mol MgCl L
= mol/L = M AgNO3

9. Learning Check How many liters of H2 gas at STP are produced
when 12.5 g Zn react with 20.0 mL of 1.50 M HCl?
Zn(s) + 2HCl(aq) ZnCl2 (aq) + H2(g)
1) L H2
2) L H2
3) L H2

10. Solution 2) 0.336 L H2 Limiting Reactant
12.5 g Zn x 1.00 mol Zn x 1 mol H2 x 22.4 L = L H2
65.41 g Zn 1 mol Zn 1 mol
L x 1.50 mol HCl x 1 mol H2 x L
1 L mol HCl 1 mol
= L H2 gas

11. Summary of Chemical Reactions
Copyright © by Pearson Education, Inc.
Publishing as Benjamin Cummings