# Unit10 - solutions

```Unit 10 Group Work – Solutions
1. 1.398 g of sodium acetate is dissolved in 345.2 mL of water. What is the concentration (M) of this solution?
2. Calculate the molarity of chloride anion in each of the following solutions:
a. 25 grams of NaCl is added to 1 L of water.
b. 25 mg of NaCl is added to 1 mL of water
c. 25 mg of magnesium chloride is dissolved in 150 mL of water.
d. 25 g of magnesium chloride and 25 g of iron (III) chloride are dissolved in 3.1 L of water.
2. Identify all water soluble ionic compounds in the list below.
Ammonium acetate
Silver Iodide
Copper (I) sulfide
Barium sulfate
Barium sulfide
Iron (II) nitrate
Zinc chloride
Ba(OH)2
AuS
Co(NO3)2
SnCl4
MoBr2
Mn3(PO4)2
(NH4)2CO3
3. 36 mL of 0.686 mM HCl is diluted to 100 mL. What is the molarity of HCl?
4. 345 mL of water is added to 160 mL of 3.2M MgCl2. What is the molarity of chloride after the dilution?
5. Describe how to prepare a 500 mL solution of 33 mM HCl from a stock solution of 1 M HCl.
6. A chemist finds an old flask with a solution of salt in the back of her lab. Using a series of laboratory
techniques, she determines that the flask contains 1.00 M Mg2+, however, using these techniques she is
unable to figure out if the anion is chloride, iodide, or bromide. When she mixes 100.0 mL of this solution
with 500 mL of 1 M AgNO3, exactly 37.554 g of solid precipitates out of solution.
a. Write balanced ionic and net ionic equations – call the unknown anion X-.
b. What ionic compound is in the flask?
7. When sodium carbonate reacts with hydrochloric acid, sodium chloride, water, and carbon dioxide gas are
produced.
a. Write balanced ionic and net ionic equations for this reaction. Make sure to include all phases.
b. If 25 mL of 0.5 M sodium carbonate is added to 50 mL of 300 mM HCl determine:
i. The concentration of NaCl produced.
ii. The concentration of sodium carbonate remaining after the reaction completes.
iii. The concentration of HCl remaining after the reaction completes
iv. The volume of water produced.
v. The volume of CO2(g) if the gas at STP.
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