Question

Find the total number of protons in 10 g of calcium carbonate.

• A. $3.0115\times {10}^{24}$
• B. $1.5057\times {10}^{24}$
• C. $2.0478\times {10}^{24}$
• D. $4.0956\times {10}^{24}$

Answer 1

The correct option is A $3.0115\times {10}^{24}$

1 mole of $CaC{O}_3$ weighs 100g.

So, 100g of $CaC{O}_3$ contains $6\times {10}^{23}$ molecules.

But, We are looking for 10g.

So in 100g $6 \times 10^{23} So in

10g $6\times {10}^{22}$ molecules.We know that,

The number of protons in a molecule is directly its atomic number.

We know that,

The number of protons in a molecule is directly its atomic number.

So, $Ca= 18

C = 6

O = $8\times 3$ = 24

Totally, 50 protons and 50 electrons in one molecule of $CaC{O}_3$

And now,

Number of protons in 10g

= Number of protons in $6\times {10}^{22}$ molecules.

= $50\times 6\times {10}^{22}$

= $3\times {10}^{24}$ protons.