1.A student dissolves 10 grams of salt in 90 grams of water. What is the % mass concentration of the salt solution? 2. A sugar solution has a 12% mass concentration and weighs 250 g in total. How much sugar (solute) is in the solution? 3.A solution is made by mixing 40 mL of alcohol with enough water to make 200 mL of solution. What is the % volume concentration? 4.A disinfectant solution contains 30% alcohol by volume in a 500 mL solution. How much alcohol is present? 5. You have 25 grams of solute and want to make a solution with a 5% mass concentration. What should be the total mass of the solution
Answer (1)
Answer:1. 10% The mass concentration is calculated as (mass of solute / total mass of solution) × 100%. In this case, it's (10 g / (10 g + 90 g)) × 100% = 10%. 2. 30 g A 12% mass concentration means 12 g of sugar per 100 g of solution. Therefore, in 250 g of solution, there are (12 g / 100 g) × 250 g = 30 g of sugar. 3. 20% The volume concentration is calculated as (volume of solute / total volume of solution) × 100%. Here, it's (40 mL / 200 mL) × 100% = 20%. 4. 150 mL In a 30% alcohol solution, 30 mL of alcohol is present in every 100 mL of solution. In a 500 mL solution, there's (30 mL / 100 mL) × 500 mL = 150 mL of alcohol. 5. 500 g A 5% mass concentration means 5 g of solute per 100 g of solution. To have 25 g of solute, you need (100 g / 5 g) × 25 g = 500 g of solution.
