What is the % by mass of a salt solutions that is made by dissolving 2.5 g of salt in 25.0 g water? 2. What is the percentage by volume of a 50 mL solution made with 25 mL of methyl alcohol? 3. What is the percent by mass of sodium chloride in a solution prepared by adding 25.0 g salt to 125.0 g water? 4. A solution of methanol is prepared by dissolving 35.0 mL of methanol in water to give a total of 115.0 mL solution. What is the % by volume concentration of methanol?​