Question

Your holding a glass of lemonade out in the sun and its not so cold and refreshing anymore so you decide to put two ice cubes in the glass. Your glass of lemonande contains 0.24kg lemonade that is 33 degrees celcius, one ice cube weighs 0.025kg and are about 0 degrees celsius. If u assume that the heat loss in your enviroment is small, what is the final degree? What would the degree be with six ice cubes instead?

Need help! How to approach this!

Answer 1

Zero change is enthalpy between the initial and final states.

Answer 2

Heat loss=heat absorb

Answer 3

Use formula
Q=mL
Q=ms*(theta2-theta1)

Answer 4

Response plz!!!

Answer 5

@shamim Show me more?

Answer 6

I have a good idea of what to do, but I don't wanna tell you something wrong. Shamim and Vincent have the right idea, but I'm not too sure on how to set up the equation lol.
Heat = mass*specific heat capacity*change in temperature
So, you have to do a conservation of energy thing with this system.

Answer 7

cant get it right... need to kow how to setup the equations..:(

Answer 8

@shamim or @vincent-lyon.fr tell me more?

Answer 9

Let the final temperature is =theta

Answer 10

So heat losses by hot water is=m*s*(theta2-theta1)=0.24*4200*(33-theta) Joule

Answer 11

Now i wanna calculate heat gains by ice

Answer 12

Heat gains by ice to become water with 0 degree celcius=mLf=0.025*2*Lf=?

Answer 13

Now heat gains by ice to become theta degree celcius=ms(theta-0)=2*0.025*4200*theta

Answer 14

Total heat gain=?

Answer 15

Use
Heat gain=heat loss
Theta=?

Answer 16

Feel free to ask for more clarification!!

Answer 17

@shamim what is Lf`?

Answer 18

Lf=latent heat of fusion

Answer 19

so 333.5?

Answer 20

Do u know the value of Lf

Answer 21

No?

Answer 22

Lf=334*10^3 joule/kg

Answer 23

Its a constant

Answer 24

yea, its just not called Lf in my country :) But what do I do with: "Now heat gains by ice to become theta degree celcius=ms(theta-0)=2*0.025*4200*theta"?

Answer 25

why 4200 there?

Answer 26

We hv to calculate total heat gain by ice

Answer 27

how does the final equation look like?

Answer 28

U hv to add 2 heat gain. U will get total heat gain by ice

Answer 29

so I put the two heat gain equations equal first? and then heat gain = heat loss?

Answer 30

Heat gain=2*0.025*334*10^3+2*0.025*4200*theta

Answer 31

aa I see!

Answer 32

Ya heat gain=heat loss

Answer 33

Theta=?

Answer 34

Medal?!!!

Answer 35

13.53?

Answer 36

degrees celsius

Answer 37

@shamim?

Answer 38

but if I put 6 ice cubes? with this formula it says -10.43 degrees
@shamim

Answer 39

but it cant because water and ice can only reach zero?

Answer 40

Now i wanna talk abt 6 cubes

Answer 41

Can u tell me how much heat loss is happening frm water of 33 degree celcius to 0 degree celcius?

Answer 42

Actually this amount of heat is not enough to melt all
the ice of 6 cubes

Answer 43

A part of ice will b melt with 0 degree celcius water and a part of ice will not melt. And this will b result

Answer 44

Response plz!!!