1
GATE CE 2022 Set 1
MCQ (Single Correct Answer)
+1
-0.33

In a water sample, the concentrations of Ca2+, Mg2+ and HCO$$_3^ - $$ are 100 mg/L, 36 mg/L and 122 mg/L, respectively. The atomic masses of various elements are : Ca = 40, Mg = 24, H = 1, C = 12, O = 16. The total hardness and the temporary hardness in the water sample (in mg/L as CaCO3) will be

A
400 and 100, respectively.
B
400 and 300, respectively.
C
500 and 100, respectively.
D
800 and 200, respectively.
2
GATE CE 2016 Set 2
Numerical
+1
-0
The hardness of a ground water sample was found to be 420 mg/L as $$CaCO_3$$. A softener containing ion exchange resins was installed to reduce the total hardness to 75 mg/L as $$CaCO_3$$ before supplying to 4 households. Each household gets treated water at a rate of 540 L/day. If the efficiency of the softener is 100%, the bypass flow rate (expressed in L/day) is .
Your input ____
3
GATE CE 2015 Set 2
Numerical
+1
-0
A groundwater sample was found to contain 500 mg/L total dissolved solids (TDS). TDS (in %) present in the sample is ________.
Your input ____
4
GATE CE 2014 Set 1
MCQ (Single Correct Answer)
+1
-0.3
Some of the nontoxic metals normally found in natural water are
A
arsenic, lead and mercury
B
calcium, sodium and silver
C
cadmium, chromium and copper
D
iron, manganese and magnesium
GATE CE Subjects
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