Question

Molecular mss is 78 empirical formula is ch how molecular is

Answer 1

Hello!

Molecular mass (of the compound) is 78 and empirical formula is CH, how molecular formula is ?

First Step: We are going to find the Molecular Mass (MM) of the Empirical Formula (EF), let's see:

if: CH

C = 1*(12 u) = 12 u

H = 1*(1 u) = 1 u

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MM(E.F) = 12 + 1 = 13 g/mol

Second Step: Knowing that the Molecular Mass of the Molecular Formula is 78 (in g/mol) and that the Molecular Mass of the Empirical Formula is 13 (in g/mol), then we will find the number of terms (n) for the molecular formula of the compound, let us see:

$n = \dfrac{MM_{M.F}}{MM_{E.F}}$

$n = \dfrac{78}{13}$

$\boxed{n = 6}$

Therefore, the Molecular Formula is the Empirical Formula times the number of terms (n), then, we have:

$M.F = (E.F)*n$

$M.F = (CH)*6$

$\boxed{\boxed{M.F=C_6H_6}}\Longleftarrow(molecular\:formula\:of\:the\:compound)\end{array}}\qquad\checkmark$

Answer:

C6H6

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