Show the dissolving of sodium carbonate, Na2CO3, in water:
What is the [CO32-]?
What is the [Na1+]?
Ø A 0.30 mol sample of CaBr2 (s) and a 0.15 mol sample of NaBr (s) are dissolved in water and
diluted to 1500 mL. What is the concentration of Br1- in the solution?
a)
.45 M
b)
.30 M
c)
.40 M
d)
.50 M
GRAVIMETRIC ANALYSIS
Ø An unknown metal cation has a +1 charge (M+). The bromide of the unknown metal, MBr, is
dissolved in enough water to make 100.0 mL of solution. The solution is then mixed with an
excess of AgNO3 solution to precipitate AgBr (molar mass = 188 g/mol). The precipitate is
collected by filtration, dried, and the following data was obtained:
Mass of MBr = 1.38 g
Mass of filter paper = 0.98 g
Mass of filter paper and AgBr = 2.86 g
Ø What is the identity of the metal chloride?
a)
KBr
b)
NiBr
c)
LiBr
d)
NaBr
Ø A 10.500 gram mixture contains calcium nitrate and potassium chloride. Excess lead (II)
nitrate solution, Pb(NO3)2 (aq), is added to precipitate out 4.227 grams of lead (II) chloride,
PbCl2 (s).
a)
What is the percent by mass of potassium chloride in the mixture?
b)
What is the percent by mass of calcium nitrate in the mixture?