Question

Atomic mass or weights are based on a scale on which carbon had an atomic mass of 12.00. Carbon and calcium combine in the ratio of 2:1 to form calcium carbide. If 22.75 g of calcium combines with 13.62 g of carbon, what is the atomic weight of calcium? Show work.

a) 40.08 g/mol

b) 42.75 g/mol

c) 43.99 g/mol

d) 46.50 g/mol

Answer 1

The atomic weight of calcium can be determined by calculating the molar mass of calcium carbide and carbon.

Step-by-step explanation:

The atomic weight of an element is based on a scale where carbon has an atomic mass of 12.00. If 22.75 g of calcium combines with 13.62 g of carbon in a ratio of 2:1 to form calcium carbide, we can determine the atomic weight of calcium by using the concept of molar mass.

To calculate the atomic weight of calcium, we need to know the molar mass of carbon and the molar mass of calcium carbide. The molar mass of carbon is approximately 12.01 g/mol, and the molar mass of calcium carbide is 64.1 g/mol. Therefore, the molar mass of calcium is (2 * molar mass of calcium carbide) + molar mass of carbon, which gives us (2 * 64.1 g/mol) + 12.01 g/mol = 140.21 g/mol for the atomic weight of calcium.

Therefore, the correct option is (d) 140.21 g/mol.