Acompound contains 75% carbon and 25% hydrogen by mass. what is the empirical formula for this compound?

Hello!

A compound contains 75% carbon and 25% hydrogen by mass. what is the empirical formula for this compound ?

data:

Carbon (C) ≈ 12 a.m.u (g/mol)  

Hydrogen (H) ≈ 1 a.m.u (g/mol)

We use the amount in grams (mass ratio) based on the composition of the elements, see: (in 100g solution)

C: 75 % = 75 g

H: 25 % = 25 g

The values (in g) will be converted into quantity of substance (number of mols), dividing by molecular weight (g / mol) each of the values, we will see:

We realize that the values found above are not integers, so we divide these values by the smallest of them, so that the proportion does not change, let us see:

Thus, the minimum or empirical formula found for the compound will be:

CH4 (Methane)  

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I Hope this helps, greetings ... Dexteright02! =)

where's the diagram?

1. for the first question, we must find the mass of the anhydrous salt, mgso₄. the molar mass for mgso₄·7h₂o is 246.47 g/mol, while that of mgso₄ is 120.37 g/mol.7.834 g mgso₄·7h₂o * 1 mol mgso₄·7h₂o/246.47 g * 1 mol mgso₄/1 mol mgso₄·7h₂o * 20.37 g mgso₄/mol = 0.647 g mgso₄

2. mass of water = mass of sample - mass of anhydrous salemass of water = 7.834 - 0.647 = 7.19 gpercent water in hydrate = 7.19/7.834 * 100 = 91.74%