#11 % Solutions Calculations Answers

What does percent mean? Since “cent” is a prefix meaning 100 Per”cent” means per 100 So 83% means 83 per 100 – Or 83 out of 100

1) a. 20g of KCl in 600 g of water. 20__ x 100 = = 3.2 %

1) b. 32g of NaNO 3 in 2000 g of water 32__ x 100 = = 1.6 %

1)c. 75 grams of K 2 SO 4 in 1500g of water __75__ x 100 = = 4.8 %

2. What is the percent by volume of methanol if 75 mL of methanol is added to 400 ml of water __75__ x 100 = = 16 %

3. What is the percent by volume of hydrogen peroxide if 25ml of hydrogen peroxide is diluted to a final total volume of 150ml? __25__ x 100 = 150 = 17 %

4. How much water will you need to mix with 5g of a compound to produce a 15% solution? 15 = __5__ x 100 (5 + X) Simplify: 15 = __500__ (5 +x) Then cross multiply: 15(5+x) = 500 then distribute the 15: x = 500 Then subtract 75 from both sides: 15x = 425 Then divide each side by 15: x = 28.3 g of water