Title: Name: _____________________________________
Author: P Lawson

Name:  _____________________________

Chemistry 30
Unit 4: Solutions
Assignment 3		Calculations involving Solution and Ion Concentrations

You must clearly show all work for your calculations. Be sure to highlight your final answer – circle it, underline it, whatever. Be sure to include the units for your answer. Failure to follow these directions will result in a loss of marks.

1.	What mass of sodium hydroxide is needed to make 500.0 mL of 0.5 M NaOH solution.

2.	What volume of 0.060 M KCl solution contains 2.39 g of KCl?

3.	Calculate the concentration of a solution prepared by dissolving 24.2 g of Fe_2(SO_4)_3 in enough water to make 250.0 mL of solution.

4.	What is the concentration of a solution prepared by dissolving 6.1 g of KSCN in enough water to make 500.0 mL of solution?

5.	Describe how to prepare 250 mL of a standard 5.00 M KNO_3 solution.  Be sure to identify any special lab equipment required. Show all calculations.

6.	Determine the volume of solution that contains 80.0 g of 2.00 M copper(II) nitrate.

7.	A student adds enough water to 120 mL of a 6.0 M solution of NaOH until the final volume of the solution is 2.0 L.  What is the concentration of the diluted solution?

8.	 What volume of a 18.0 M H_2SO_4 solution is required to make 2.5 L of a 1.0 M H_2SO_4 solution?

9.	What mass of ammonium chloride, NH_4Cl, is present in 0.30 L of a 0.40 M NH_4Cl solution?

10.	A chemist evaporates 25.0 mL of NaCl solution to dryness and finds 0.585 g of NaCl.  What was the molarity of the original solution?

11.  What is the concentration of  an ammonia solution prepared by diluting 75.00 mL solution of concentrated ammonia, NH_3 (14.8 M) to a volume of 2.000 L.

12.	Calculate the concentrations of the ions in the following solutions. Be sure to write a balanced equation for each dissociation reaction. You MUST remember to include proper ion charges for all ions! The first equation is shown for you.

	a)  an aqueous solution containing 0.075 M strontium nitrate, Sr(NO_3)_2

			Sr(NO_3)_2  Sr^2+(aq) + 2 NO_3^- (aq)

	b)  a 0.15 M solution of  sodium sulfate, Na_2SO_4

	c)  a 2.000 L aqueous solution containing 107.0 g ammonium chloride, NH_4Cl

		 Hint: Begin by calculating the concentration of the NH_4Cl  solution.

	d)  250.0 mL solution containing 25.50 g of sodium phosphate

		Hint: Be sure to write the correct chemical formula for sodium phosphate. Then determine the concentration of the sodium phosphate solution. Write a balanced dissociation equation in order to next determine the concentration of the ions in solution.

Unit 4: Solutions	Assignment 3