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 or calcium combine with 13.62 g carbon, what is the atomic weight do calcium? Show work.

Answer 1

40.088 ≈ 40

Step-by-step explanation:

We'll begin by calculating the number of mole in 13.62g of carbon. This is illustrated below:

Mass of carbon = 13.62g

Atomic weight of carbon = 12

Mole of carbon =..?

Mole = mass /atomic weight

Mole of carbon = 13.62/12

Mole of carbon = 1.135 mole

Next, we shall determine the number of mole of calcium needed to react with 1.135 mole of carbon.

This is illustrated below:

2C + Ca —> CaC2.

From the balanced equation above,

2 moles of C reacted with 1 mole of Ca.

Therefore, 1.135 mole of C will react with = (1.135 x 1)/2 = 0.5675 mole of Ca.

Therefore, 0.5675 mole of calcium, Ca is needed.

Now, we can determine the atomic weight of calcium as follow:

Mass of calcium = 22.75g

Mole of calcium = 0.5675 mole

Atomic weight of calcium =..?

Mole = mass /atomic weight

0.5675 = 22.75 / atomic weight

Cross multiply

0.5675 x atomic weight = 22.75

Divide both side by 0.5675

Atomic weight = 22.75 / 0.5675

Atomic weight = 40.088

Therefore, the atomic weight of calcium is 40.088