Question

Di- Ethyl zinc is a chemical used in the library to protect books from worms, its composition is 53% Zinc, 38.9% Carbon, and 8.1% Hydrogen (At mass of Zn=65.4, C=12, H=1). Find the empirical formula of a compound

Answer 1

ZnC4H10

Step-by-step explanation:

The empirical formula of a compound refers to the formula that gives the simplest whole number ratio of each atoms of the elements in the compound.

The empirical formula is calculated thus:

The given percentages in the question represent the mass in grams of each element in the compound.

Zinc= 53%, C= 38.9%, H= 8.1% which represents 53g, 38.9g and 8.1g of each element respectively.

Molar Mass of Zn= 65.4 g/mol

Molar Mass of C= 12 g/mol

Molar Mass of H= 1 g/mol

Step 1: Divide the mass of each element by the molar mass given to convert to moles:

Zn= 53/65.4 = 0.81moles

C= 38.9/12 = 3.24moles

H= 8.1/1 = 8.1moles

Step 2: Divide each mole value by the smallest number of moles calculated, which is 0.81moles:

Zn= 0.81/0.81 = 1

C= 3.24/0.81 = 4

H= 8.1/0.81= 10

This is the mole ratio represented in the subscript of each element in the empirical formula:

That is, Zn (1) C (4) H (10)

Empirical formula= ZnC4H10