From the given empirical formula and molar mass, find the molecular formula of each compound. c6h7n, 186.24 g/mol c2hcl, 181.44 g/mol c5h10ns2,296.54 g/mol

C6H7N = C12H14N2

C2HCl = C6H3Cl3

C5H10NS2 = C10H20N2S4

Explanation:

There are certain steps you need to follow to find the molecular formula:

1. Determine the number of moles = subscript

So for the first one

C has 6 moles

H has 7 moles

N has 1 mole

2. Multiply moles by atomic mass = atomic mass found on periodic table

So...

6 × 12 = 72

7 × 1 = 7

1 × 14 = 14

Then we going to add all of them together to get the empirical weight:

72 + 7 + 14 = 93

3. Divide molar mass by the empirical weight

So

186.24 ÷ 93 = 2

4. Multiply each mole by molecular weight

So...

2(C6H7N) = C12H14N2 = Molecular formula

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.