If I have 5.6 moles of bobby pins, how many bobby pins do I have?

What is the name of this hydrocarbon?

1. combine iron and copper (ii) sulfate solution. (hint: iron will form the iron (iii) ion) fe + cuso4 → 2. combine lead (ii) nitrate and potassium iodide solutions. pb(no3)2+ kl → 3. combine magnesium metal and hydrochloric acid solution. mg + hcl → 4. electrolysis (splitting) of water. h2o → 5. burning magnesium. mg + o2 →

Write the empirical chemical formula of calcium with a mass percent of 38.8, phosphorus with a mass percent of 20.0, and oxygen with a mass percent of 41.3.