Question

If $1000$ g of a water sample contains $10$ g of $CaC{O}_3$, then the hardness of that water sample is:

• A. $100$ ppm
• B. $500$ ppm
• C. $10000$ ppm
• D. $20000$ ppm

Answer 1

Answer: (C)

$10000$ ppm

${10}^3$ gms of sample of water contain $=10$ gms of $Ca{CO}_3$

${10}^6$ gms of sample of water contain $=\frac{10}{{10}^3}\times {10}^6={10}^4$ gms of $Ca{CO}_3$

$100$ gms of $Ca{CO}_3$ has hardness $=100$ ppm

${10}^4$ gms of $Ca{CO}_3$ has hardness = $\frac{100}{100}\times {10}^4={10}^4$ ppm