ASAP WILL GIVE BRAINLIEST!
1. A 1.68 g sample of iron reacts with 0.72 g oxygen to form rust, Fe2O3, iron (III) oxide. What is the per cent composition (% m/m) of the elements in the rust?
2. If a solution of Na2SO4 in water weighs 220 g and contains 35 grams of Na2SO4, what is the per cent composition (% m/m) of the Na2SO4 in the solution?
3. A solution is made by combining 25 mL of ethanol (C2H6O) with water to produce 255 mL of solution. Determine the per cent composition (% v/v) of ethanol in this solution.
4. A solution is prepared by dissolving 96 mL of hydrogen peroxide (H2O2) in enough water to make 2800 mL of solution. Determine the per cent composition (% v/v) of hydrogen peroxide in this solution.
5. What is the molarity of a solution made of water added to 45 g AgNO3 to produce 650 mL of solution?