Question

6.7gm of water at 50° C be divided in two parts such that when one part of mass T'gm is turned into ice at 0° C, it would release sufficient amount of heat to vaporize the other part. 10. Then (x-0.49) gm is equal to

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Answer 1

Explanation:

Given info: 6.7 gm of water at be divided in

two parts such that when one part of mass 'x' gm is turned into ice at, it would release sufficient amount of heat to vapourize the other part.

To find : The value of x is ..

solution : case 1: x gm is turned into ice.

so, heat released by x gm water, H = mLf = x gm x 80 cal/gm

[ Lf is latent heat of fusion, for ice = 80 cal/ gm]

= 80x cal

case 2 remaining (6.7 - x) gm is turned into so, heat gained by (6.7 - x) gm of steam, H:

steam.

=

mLv

= (6.7 - x) gm x 540 cal/gm

[ Lv is latent heat of vaporisation, for steam = 540 cal/g]

= 540 (6.7 - x) cal

heat gained = heat released

F 80x540(6.7 - x)

→ 8x = 54 x 6.7 - 54x

→ 62x = 54 × 6.7

⇒ x = 54 × 6.7/62 = 5.8 g

Therefore the value of x is 5.8