Answer:
6. a. 5.53 (m/m) %; b. 0.7490M
7. 0.156M
Explanation:
6. In the solution of KCl, there are 1.396g of KCl in 25.225g of solution. As mass/mass percent is:
Mass solute / Mass solution * 100
The mass/mass percent of KCl is:
a. 1.396g KCl / 25.225g solution * 100
5.53 (m/m) %
b. Molarity is moles of solute per liters of solution:
<em>Moles KCl -Molar mass: 74.55g/mol-:</em>
1.396g KCl * (1mol / 74.55g) = 0.018726 moles KCl
<em>Volume in liters: 25mL = 0.025L</em>
Molarity:
0.018726 moles KCl / 0.025L = 0.7490M
7. 0.90% means 0.90g of NaCl in 100g of solution:
<em>Moles NaCl -Molar mass: 58.44g/mol-:</em>
0.90g NaCl * (1mol / 58.44g) = 0.0154 moles NaCl
<em>Volume in Liters:</em>
100g * (1mL / 1.01g) = 99mL = 0.099L
Molarity:
0.0154 moles NaCl / 0.099L =
0.156M
