Solution problems

If we dissolve 87 grams of silver into 200 grams of gold, the resulting alloy is what percent silver?

87g / 287 grams = = 30.3%

A sample of stainless steel is 17% chromium. How many grams of chromium would be present in a 465 g mass of this stainless steel?

465g x.17 = 79.05g

14 grams of sugar are dissolved in to 165 mL of water. The resulting solution is what percent sugar?

14g / 165 mL = =8.5%

160 mL of a 2.5% salt solution would have how many grams of salt?

160 mL x.025 = 4 g

– 37 mL of vinegar are dissolved into 150 mL of water. The resulting solution is what percent vinegar?

– 37 mL / 187 mL =.198 = 19.8%

How many mL of vinegar are required to make 500 mL of a 20% solution of vinegar?

500 mL x 0.2 = 100 mL

If 2 moles of salt are dissolved into 150 mL of water, what is the molarity of the resulting solution?

Remember Molarity = M M = moles solute / Liter solution  2 mol  150 mL =.15 L  2mol /.15 L = 13.3 M

If 37 grams of KOH are dissolved into 500 mL of water, what is the molarity?

 37 g / (56 g/mol) = 0.66 mol  500 mL = 0.5 L  0.66 mol / 0.5 L = 1.32M

How many grams of NaOH are required to make 125 mL of a 2.6 M solution?

2.6 mol / 1 L = x mol / L; x =.325 mol mol x (40 g/mol) = 13 g

For a “how many grams problem” (M) x (V in Liters) x (molar mass) = grams