How Much Steam Is Needed to Heat Water from 24°C to 90°C?

[Jahnavi]

Homework Statement

The temperature of 100 gm of water is to be raised from 24°C to 90°C by adding steam to it .Calculate the mass of the steam required for this purpose .

Homework Equations

Latent heat of vaporisation of steam = 540 Cal/g

The Attempt at a Solution

[/B]
Let 'm' be the mass of steam added.

Heat released by steam as it condenses into
water = 540m

Heat released by condensed water as it moves
from 100°C to 90°C = mx1x10 = 10m

Total heat released = 540m+10m= 550m

Heat required by 100gm water to raise its temp from
24°C to 90°C = 100x1x66

Equating the two , 550m = 6600

m = 12gm

Is it correct ?

 

[haruspex]

Homework Statement

The temperature of 100 gm of water is to be raised from 24°C to 90°C by adding steam to it .Calculate the mass of the steam required for this purpose .

Homework Equations

Latent heat of vaporisation of steam = 540 Cal/g

The Attempt at a Solution

[/B]
Let 'm' be the mass of steam added.

Heat released by steam as it condenses into
water = 540m

Heat released by condensed water as it moves
from 100°C to 90°C = mx1x10 = 10m

Total heat released = 540m+10m= 550m

Heat required by 100gm water to raise its temp from
24°C to 90°C = 100x1x66

Equating the two , 550m = 6600

m = 12gm

Is it correct ?

Looks good.