Question

Question #b27d1

Answer 1

`6.022140857 × 10^23`

Explanation:

First, we need to find what percentage of the Calcium Carbonate is Carbon.

The relative atomic mass of Calcium Carbonate is = (`CaCO_3`) = `40 + 12 + (16xx3) = 100`

The relative atomic mass of Carbon is 12, so the percentage of Carbon in Calcium Carbonate is:
`12 / 100 xx 100% = 12%`

So in 100g of Calcium Carbonate, there is 12g of Carbon.
We then find how many moles of Carbon there is:
`"moles" = "mass" / "relative atomic mass"`
So there is `12/12 = 1` mole

In a mole of any substance, there are `6.022140857 × 10^23` atoms - this is known as the Avogadro constant.

Hope this helps:) Let me know if I can do anything else.