if you know the relative mass formula (M r) of the compound. Add up the atomic masses of the atoms in the empirical formula. The empirical formula of a hydrocarbon is CH 2 and its M r is 42.

work out how many atoms of each element are in the chemical formula add together the A r values for all the atoms of each element ...

was less than the atomic mass (average mass of the atom). For example, a helium atom has an atomic mass of 4, but an atomic number (or positive charge) of 2. Since electrons have almost no mass ...

1. Convert kilograms/second to grams per second. 1 kg = 1000 grams. If the mass flowrate is 0.25 kilograms/second, convert this to 250 grams/second. 2. Convert grams to moles, using the molar mass of ...