Question

25 ml samples of distilled water, tap water and boiled water required, respectively, lmL 13mL and 5mL of soap solution to form a
permanent lather. The ratio of temporary to permanent hardness in the tap water is
(A) 32
(B) 23
(C) 12
(D) 2:1

Answer 1

Answer:

HI

answer is d

hope it helps

Answer 2

Answer:

2 : 1

Explanation:

Volume of soap solution used effectively in tap water =13−1=12 mL∴ Temporary + Permanent hardness =12 mL

Volume of soap solution used effectively in boiled water =5−1=4 mL

Permanent hardness =4 mL

∴ Temporary + Permanent hardness =12 mL

Permanent hardness =4 mL

Temporary hardness =8 mL

Temporary hardness/Permanent hardness  = 8/4 = 2 : 1 (D)