Softening MCQ Quiz in मल्याळम - Objective Question with Answer for Softening - സൗജന്യ PDF ഡൗൺലോഡ് ചെയ്യുക
Last updated on Mar 22, 2025
Latest Softening MCQ Objective Questions
Top Softening MCQ Objective Questions
Softening Question 1:
Temporary hardness of water can be removed by:
Answer (Detailed Solution Below)
Softening Question 1 Detailed Solution
Explanation:
Hardness of water:
Hardness in water is that characteristic which prevents the formation of sufficient leather or foam, when such hard waters are mixed with soap. It is usually caused by the presence of calcium and magnesium salts present in water, which form scum by reaction with soap.
Water softening:
The process of removal of hardness from water is known as Water softening
Removal of hardness;
1. Temporary hardness
The temporary or carbonate hardness, which is caused by carbonates ad bicarbonates of Ca and Mg or bivalent cations.
The methods of removing temporary hardness
- Boiling
- Addition of lime.
2. Permanent hardness
The permanent or non carbonate hardness, which is caused by the sulphates, chlorides and nitrates of Ca and Mg are removed by special methods.
The methods of removing permanent hardness
- Lime soda process
- Base exchange process
- Demineralization.
Softening Question 2:
Water is to be supplied to 4 households at a rate of 500 ltr/house per day. The final hardness of water while supplying to household is kept at 75 mg/ltr. A part of water from the source, passes through a hardness removal system which have an efficiency of 100 rest of the water are transported through a bypass system, later both of them are mixed and supplied to the household. If the hardness at the source is 500 mg/ltr. Then choose the correct statements out of the following:
Answer (Detailed Solution Below)
Softening Question 2 Detailed Solution
Explanation
The flowchart for the whole distribution system is shown in the figure below-
Since there are four households in total with a requirement of 500 ltr per house per day,
the total discharge = 4 × 500 ltr per house per day = 2000 ltr per day
Given, the hardness at the source = 500 mg/l
the hardness to be maintained while supplying to the household = 75 mg/l
Assume a discharge of Q1 ltr per day passes through the hardness removal system and rest through the bypass,
As the water passes through the hardness removal system, the hardness will become aero as efficiency is 100 percent.
then the hardness concentration at the household:
Final hardness concentration \(= \frac{{{Q_1} \;\times \;0\; + \;{Q_2}\; \times \;500}}{Q} = \frac{{{Q_1}\; \times \;0\; +\; (Q \;- \;{Q_1})\; \times \;500}}{Q} = 75\)
⇒ Putting Q = 2000 ltr/d, (2000 – Q1) × 500
= 2000 × 75
⇒ Q1 = 1700 ltr/day
⇒ Q2 = Discharge passing through the bypass
= 2000 – 1700
= 300 ltr/day
= 300/24
= 12.5 ltr/hr
∴ Options 3) and 4) are correct.