Question

A binary compound created by reaction of chromium and an unknown element E contains 68.47% Cr and 31.53% E by mass. If the formula of the compound is Cr2E3, calculate the atomic mass of E.

Answer 1

Answer:

The molar mass of E = 15.96 g/mol

Explanation:

Step 1: Data given

The compound Cr2E3 contains 68.47 % Cr and 31.53 % E

The molar mass of Cr = 52 g/mol

⇒ 2*52 = 104 g/mol

The molar mass of Cr2E3 = 2*52 g/mol + 3X

Step 2: Calculate mass of Cr2E3

Cr is 68.47 %

Mass of Cr = 104 grams

Cr2E3 is 100%

Mass of Cr2E3 = 151.89 grams

Molar mass of Cr2E3 = 151.89 g/mol

Step 3: Calculate mass of E

Mass of E3 = mass of Cr2E3 - mass of Cr

Mass of E3 = 151.89 grams - 104 grams

Mass of E3= 47.89 grams

Mass of E = 15.96 grams

The molar mass of E = 15.96 g/mol

Answer 2

Answer: The atomic mass of E is 16

Explanation:Please see attachment for explanation