Answer
Verified
414.6k+ views
Hint: ppm stands for parts per million. We can say that if the sample of water contains the calcium or magnesium salt whose weight (in ppm) is equal to its molecular weight (in g/mol), then the hardness of water is 100%.
Complete step by step solution:
We are given the concentration of calcium sulphate in ppm in the solution. Here, we need to find the degree of hardness of the solution.
- If calcium ions are present in the water, then the water is called hard water. The water which does not contain calcium or magnesium salts is called soft water.
- Let’s find the molecular weight of calcium sulphate first.
Molecular weight of $CaS{O_4}$ = Atomic weight of Ca + Atomic weight of S + 4 (Atomic weight of O)
Molecular weight of $CaS{O_4}$ = 40 + 32 + 4(16) = 136$gmmo{l^{ - 1}}$
- Now, we can say that if the sample contains 136 ppm of calcium sulphate, then the degree of hardness of the water sample would be 100%. So, here it is given that there is 68 ppm of calcium present in the solution. So, the hardness of the water will be $\dfrac{{68}}{{136}} \times 100\% = 50\% $ .
Thus, we obtained that the hardness of the sample of water that contains 68 ppm of calcium sulphate is 50%.
So, the correct answer to this question is (D).
Note: There are two types of hardness of water; permanent and temporary. Permanent hardness is present if water contains calcium and magnesium metal’s chloride or carbonates. If calcium or magnesium hydrogen carbonates are present, then the harness is called temporary hardness.
Complete step by step solution:
We are given the concentration of calcium sulphate in ppm in the solution. Here, we need to find the degree of hardness of the solution.
- If calcium ions are present in the water, then the water is called hard water. The water which does not contain calcium or magnesium salts is called soft water.
- Let’s find the molecular weight of calcium sulphate first.
Molecular weight of $CaS{O_4}$ = Atomic weight of Ca + Atomic weight of S + 4 (Atomic weight of O)
Molecular weight of $CaS{O_4}$ = 40 + 32 + 4(16) = 136$gmmo{l^{ - 1}}$
- Now, we can say that if the sample contains 136 ppm of calcium sulphate, then the degree of hardness of the water sample would be 100%. So, here it is given that there is 68 ppm of calcium present in the solution. So, the hardness of the water will be $\dfrac{{68}}{{136}} \times 100\% = 50\% $ .
Thus, we obtained that the hardness of the sample of water that contains 68 ppm of calcium sulphate is 50%.
So, the correct answer to this question is (D).
Note: There are two types of hardness of water; permanent and temporary. Permanent hardness is present if water contains calcium and magnesium metal’s chloride or carbonates. If calcium or magnesium hydrogen carbonates are present, then the harness is called temporary hardness.
Recently Updated Pages
How many sigma and pi bonds are present in HCequiv class 11 chemistry CBSE
Why Are Noble Gases NonReactive class 11 chemistry CBSE
Let X and Y be the sets of all positive divisors of class 11 maths CBSE
Let x and y be 2 real numbers which satisfy the equations class 11 maths CBSE
Let x 4log 2sqrt 9k 1 + 7 and y dfrac132log 2sqrt5 class 11 maths CBSE
Let x22ax+b20 and x22bx+a20 be two equations Then the class 11 maths CBSE
Trending doubts
Fill the blanks with the suitable prepositions 1 The class 9 english CBSE
At which age domestication of animals started A Neolithic class 11 social science CBSE
Which are the Top 10 Largest Countries of the World?
Give 10 examples for herbs , shrubs , climbers , creepers
Difference between Prokaryotic cell and Eukaryotic class 11 biology CBSE
Difference Between Plant Cell and Animal Cell
Write a letter to the principal requesting him to grant class 10 english CBSE
Change the following sentences into negative and interrogative class 10 english CBSE
Fill in the blanks A 1 lakh ten thousand B 1 million class 9 maths CBSE