Question

Chalk contains calcium, carbon and oxygen in the ratio 10: 3:12. Find the percentage of calcium in the chalk.


step by step please ​

Answer 1

Chalk contains Calcium, Carbon, and Oxygen in the ratio 10 : 3: 12. Find the percentage of

Carbon in chalk.

(ii) If in a stick of chalk, Carbon is 3 g, what is the weight of the chalk stick?

Solution:

(i) Given ratio = 10 : 3 : 12

Total part = 10 + 3 + 12 = 25

Part of Carbon =

\frac{3}{25}

Percentage of Carbon part in chalk = \frac{3}{25}\times100=12\%

ii) Quantity of Carbon in chalk stick = 3 g

Let the weight of chalk be x g.

Then, 12% of x = 3

\Rightarrow\ \frac{12}{100}\times x=3\Rightarrow x=\frac{3\times100}{12}=25\ g

Hence the weight of chalk stick is 25 g.