Question

A pure sample of CaCO, contain 100 moles of total atoms. What is the mass of sample
(A) 1 kg
(B) 2.5 kg
(C) 2.0 kg
(D) 1.66 kg​

Answer 1

Answer:

I am confused in 2.5 or 2.0 kg

Answer 2

Answer:

c) 2kg

Explanation:

Sample element = CaCO3 (Given)

Total number of moles = 100 (Given)

One molecule of CaCO3 contains five atoms which are - one of Ca, one of C, and three of O.

Thus, if the sample contains 100 total moles of atoms, it means that it contains 20 moles of CaCO3 molecules.

One mole of CaCO3 has a mass of - 40 + 12 + 3 × 16 = 100g

Mass of sample = 20 × 100 = 2000

Thus, the mass of sample​ is 2000g

Converting grams into kg = 2000 = 2kg.