Final answer:
The hardness of the water sample is 10 ppm.
Step-by-step explanation:
The hardness of water is a measure of the concentration of calcium and magnesium ions in the water. In this question, we can determine the temporary hardness of the water sample using the titration results.
Given that 50 ml of water sample requires 10 ml of M/50 HCl for complete neutralization, we can use the formula:
Hardness (ppm) = (Volume of HCl used in titration × 50,000) / Volume of water sample
Substituting in the values, we get:
Hardness (ppm) = (10 ml × 50,000) / 50 ml = 10,000 ppm
Therefore, the hardness of the water sample is 10,000 ppm, which is equivalent to 10 ppm.