The empirical formula of a compound is determined to be ch2o, and its molecular mass is found to be 90.087 g/mol. determine the molecular formula of the compound, showing your work.

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 →

8.98 dm3 of hydrogen gas is collected at 38.8 °c. find the volume the gas will occupy at -39.9 °c if the pressure remains constant.

About 3% of the water on earth is freshest. only about 40% of that freshwater is available for human use. why is so much freshwater unavailable for human use?