Question

You are given a sample of a Group II metal chloride, but the identity of the metal is unknown. Knowing that all Group II metal chloride compounds have the general formula, MCI2 and that the percentage of chlorine in the compound is 34.1%, what is the identity of the unknown substance?​

Answer 1

Answer:

The identity of unknown substance is Barium.

Explanation:

The given compound has a formula of MCl2. And the percentage of chlorine in this compound is said to be 34.1 %. But, we know that the mass of chlorine in this compound is, 35.5*2 = 71 g

Therefore, if we let x be the total mass of the compound, then:

34.1% of x = 71 g

(0.341)x = 71 g

x = 71 g/0.341

x = 208.2 g

Hence, the mass of other atom M, must be:

M = x - 71 g

M = 208.2 g - 71 g

M = 137.2 g

Now, we look into periodic table in group II. We find that the element is Barium with atomic mass of 137 g.

The identity of unknown substance is Barium.