Question 2: The mass of 5 moles of an element X is 60 g. Calculate the molar mass of this element. Name the element.

Solution

Molar mass of the element X

Given mass of the element X = 60 g

No of moles of the element = 5

Therefore, mass of 1 mole of the element = molar mass of the element X = 60/5 = 12 g

Identification of X:

The molar mass of X is 12 g. Now 12 g is the molar mass of element C. Therefore, the element in the problem must be Carbon.