Question

How much heat is needed to convert 914 g of ice at -30°C to steam at 118°C? (The specific heats of ice and steam are 2.03 J/g·°C and 1.99 J/g·°C, respectively.)

Answer 1

@dtan5457

Answer 2

Two phase changes, a even longer question LOL

Answer 3

oh xD oh man

Answer 4

Alright give me a few minutes again

Answer 5

okay thanks

Answer 6

Hmm, are they missing the heat of fusion and heat of vaporization?

Answer 7

Or do we plug that in our selves?

Answer 8

we plug that in ourselves im pretty sure

Answer 9

Heat of Fusion for H20 is 6.02kJ/mol
Heat of Vaporization is 40.7kJ/mol

Answer 10

lol it's alright, i won't use them anyways (more comfortable for me)

Answer 11

1. Heat needed to raise temperature from -30 to 0 (to get it to melting point)

914 g x 2.03 x 30=55.66 KJ

2. Heat needed to phase shift it from a solid to a liquid

333 (fusion heat of water) x 914=304.362 KJ

3. Heat needed to raise water temperature to boiling point (0 to 100)

914 x 4.19 (specific heat of water) x 100=382.97 KJ

4. Heat needed to make the phase shift from liquid to gas

914 x 2260(heat of vaporization) =2,065.64 KJ

5....One final step, can you give it a try and figure this one out? :P

Answer 12

For the last step, you need to use the given specific heat of steam

Answer 13

I'll give you a hint, it's the amount of energy needed to change the steam from 100 degrees to 118

Answer 14

okay ill see if i still need hepl :D thanks!

Answer 15

Alright, see if you can figure out that last step and tag me if you need more assistance.

Answer 16

kk

Answer 17

For the last step, wouldn't I just do 1.99 x 18? @dtan5457

Answer 18

Don't forget the mass..

Answer 19

x 914

Answer 20

yes, and remember to divide by 1000 to keep it in KJ....i'm assuming that's what your question wanted

Answer 21

it doesn't specify actually but I did all my steps in KJ so..

Answer 22

yep alright! thank you haha you helped so much

Answer 23

np. got any more problems?

Answer 24

uhm one sec haha

Answer 25

I got the wrong answer lmao

Answer 26

I suck at chem lol

Answer 27

wrong answer? how so? what was the correct answer?

Answer 28

I put in 32.7 and it marked the answer wrong

Answer 29

wait, as the FINAL answer?

Answer 30

I have 7 tries left to get the right answer

Answer 31

wait one sec

Answer 32

yah..? do i add all of them up?

Answer 33

Bro you need to add up all my other steps, the total heat released is over 2500KJ LOL

Answer 34

Oh O.o Told you i was dumb at chemistry lmfao

Answer 35

nah, just a silly mistake. if you were able to get the last step yourself (which you did), i think you have a decent idea of what to do.

Answer 36

Yah hopefully haha

Answer 37

add them all up and let me know if that brings the correct answer ^_^

also look at your question if it asks for specific units

Answer 38

if it asks for joules you'l multiply it all by 1000

Answer 39

Units

Answer 40

is in kJ

Answer 41

if the question asks for KJ, then yeah, your fine

Answer 42

i got 35548.112

Answer 43

now i divide by 1000 and i got 25.548 lol

Answer 44

35*

Answer 45

this is for the last step right?

Answer 46

Sike nvm LOL

Answer 47

2841.37 was my final answer

Answer 48

well i'm assuming you know how to add, and that answer sounds about right so...go for it

Answer 49

Sweet! Thank you!

Answer 50

it was correct?

Answer 51

okay last one? haha

Answer 52

yeah it was

Answer 53

LOL nice! I could use the practice...so tag me onto a new question

Answer 54

okay haha