Worksheet 4D:
Solution Calculations
Leader:
Course:
Instructor:
Date:
Sara
Chem177
Bonaccorsi
2/19/14
Supplemental Instruction
Iowa State University
Dilution
1) In lab you mix 23.5 grams of copper (II) Nitrate (molar mass = 187.6) into 193 mL
of water.
a. What is the morality of the solution?
23.5 g Cu(NO3)2 * (1mol/187g) = .649 M1
.193L H2O
b. You then dilute it to .500 L, at which point the concentration of the solution
is what?
M2=.649*.193/.500= .251 M
Limiting Reagent/ Solution Stoichiometry
2) 3Au(NO3)2 (aq) + 2Li3PO4 (aq)  6LiNO3 (aq) + Au3(PO4)2 (s)
a. What is the net ionic equation for the reaction?
Au2+ (aq) + 2NO3- (aq) + 3Li+ (aq) + PO43- (aq)
 6Li+(aq) + 6NO3- (aq) + Au3(PO4)2 (s)
b. If you start with 10.0 mL of 6.00 M Gold (II) Nitrate and you add 113 mL of
water what is the new concentration?
10.0 mL * 6.00 mol/L = (113 mL+10.0) * M2
M2 = .488 M
c. You react it with .0500 moles of Lithium phosphate. How many moles of
solid is produced?
(.488 mol gold/L * .123L) * (1 mole solid/3 moles gold) = .0200 mol solid
.0500 mol Li * ( 1 moles solid/2 moles Li) = .0250 moles solid
Gold limiting
3) In lab you are performing a titration to find the concentration of a 25.6 mL
solution of H2SO4. You start by dissolving 8.56 g solid KOH (molar mass = 56.1
g/mol) in 50.0 mL water. You then use 11.7 mL of that solution to titrate the
H2SO4(aq).
a. Write out the molecular and net ionic reaction?
2KOH (aq) + H2SO4(aq)  2H2O (l) + K2SO4 (aq)
b. What is the concentration of the basic solution you made?
8.56 g KOH (1 mol KOH / 56.1 g KOH) = 3.05 M
.0500 L H2O
c. What is the unknown concentration of the acid solution?
.0117 L base * 3.05 moles base * 1 mole acid *
1
1 L base
2 moles base .0256 L base
= .697 M
1060 Hixson-Lied Student Success Center  515-294-6624  sistaff@iastate.edu  http://www.si.iastate.edu