Question

In an experiment,17 g of ice is used to bring down the temp of 40 g of water at 34 Degree C to its freezing point.
sp heat cap of water is 4.2. J G K .
cal sp latent heat cap of ice

Answer 1

@imqwerty

Answer 2

ok the temp changes from 34 to 0 so change in temp =34
\[\Delta Q=ms \DelataT\]
\[\Delta Q=40 \times 42 \times 34\]
this is amt energy released by water=amt of energy received by ice

specific latent heat =energy received/mass

=40x42x34/17
=3360J kg^-1

Answer 3

that is\[\Delta Q=ms \Delta T\]

Answer 4

It should be 336 not 3360

Answer 5

@imqwerty
@Michele_Laino

Answer 6

I think that the procedure of @imqwerty is right!

Answer 7

under the hypothesis that all the ice will be melted

Answer 8

I remember my teacher saying we have equate the equations...

Answer 9

We have 2 equations in the question

Answer 10

that's what she said

Answer 11

heat lost = heat gained...??

Answer 12

correct! we have a energy transfer

Answer 13

I can't seem to figure out the equations.. >_>

Answer 14

do you agree that the amount of heat given by water will all be absorbed by the ice?

Answer 15

yes

Answer 16

so heat energy given by water=heat energy taken by ice

Answer 17

yes

Answer 18

can you find how much heat will be given by water to go from 34 degree C to freezing point i.e., 0 degree C?

Answer 19

Q = mL + mc*delta T

Answer 20

what is L?
L=latent heat?

Answer 21

yep

Answer 22

in this case we are just bringing water to 0 degree C and not converting it into ice
so no latent heat will be required
so\[Q=ms \Delta T\]

Answer 23

The original has a prob

Answer 24

if the final ans is 336 then it should be 4.2 instead of 42

Answer 25

i think we have to convert those joules to calories
so 4.2J~1cal

so this way 42J=4.2cal

Answer 26

from your data I read \(4.2 \,J/(grams \cdot K)\)

Answer 27

OHHH goddd!!!!!
I READ THAT 42!!!!!!!!!!!

Answer 28

>.<
D: nvm
so we have this-
\[Q=ms \Delta T\]\[Q=40 \times 4.2 \times 34\]this is amt of energy received by ice
so

latent heat=energy received/mass
\[LatentHeat=\frac{ 40\times 4.2 \times 32 }{ 17 }=336\]
thanks @Michele_Laino !! :)

Answer 29

:)

Answer 30

Thanks both of you...!

Answer 31

:)