Determine the empirical formula of an oxide of Iron which has 69.9% Iron and 30.1% dioxygen by mass. [Atomic mass of `Fe=56, O=16`]

The simplest formula of a compound containing 21.9% Mg, 27.8% P and 50.3% O by mass is :

Find the empirical formula of a compound which contain 33.18% of carbon,4.60% of hydrogen, 29.49% of oxygen and 32.72%of chlorine(At masses: C=12, H=1. O=16, Cl=35.5)

Calculate the percentage of nitrogens in NH_(3) . (Atomic mass of N=14, H=1 amu)

0.22 g of a hydrogen (i.e., a compound conatining carbon and hydrogen only) on complete combustion with oxygen gave 0.9 g water and 0.44 g carbon dioxide. Show that these results are in accordance with the law of conservation of mass (atomic mass of C = 12, H = 1, O = 16) .

Which has more number of atoms 100 gms of Sodium or 100 grams of iron given atomic mass of Na = 234 , Fe = 564

What is the simplest formula of the compound which has the following percentage composition: carbon 80%, Hydrogen 20%, If the molecular mass is 30, calcualte its molecular formula.