# A compound is known to have an empirical formula of CH and a molar mass of 78.11 g/mol. What is its molecular formula?

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The molar mass of Carbon (C) is 12.01 g/mol, and the molar mass of Hydrogen (H) is 1.00 g/mol. Adding these togther gives us the molar mass of the empirical formula:

molar mass CH = (12.01 g/mol) + (1.00 g/mol) = 13.01 g/mol

We know that molar mass of the given compound to be 78.11 g/mol; dviding that by the molar mass of the empirical formula gives us a mole ratio:

mole ratio CH = (78.11 g/mol) / (13.01 g/mol) = 6

So for 6 moles of carbon we have 6 moles of hydrogen, or

C6H6, otherwise known as Benzene.

Empericalformula of CH and a molar mass of 78.11

**To find the molecular formula: **

1.** Find the molar mass of EF:**

CH:

Carbon: 1x12= 12

Hydrogen= 1x1= 1

Molar mass 13

2. **Write the molar mass of the actual compound given: **

78.11

3. **Make a proportion of the molar mass: ` `**

**`(MFM)/(EFM)` = `(78.11)/(13)`` `**

**`cong` 6**

4.** Multiply the number to the emperical formula **

**C(6)H(6)= **

**C6H6**

**` ` **

Molar Mass / Empirical Formula mass = the factor!

Molar Mass = 78.11 g/moL

Empirical Formula mass = ?

- CH = (12.01) + (1.00 ) = 13.01 g/mol

So...

(78.11 g/moL) / (13.01g/moL EF mass) = 6

'6' is the factor

(CH)6 = C6H6

Molecular Formula = C6H6