Question

when a 140g piece of metal at 70 degree Celsius is placed in 220g of water at 0 degree Celsius, the metal is cooled, and the water is warmed and both come to a final temperature of 10 degree Celsius. What is the specific heat of the metal?

Answer 1

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Answer 2

wow, this one is thermodynamics right?

Answer 3

yes

Answer 4

its actually physics but it's considered to be in the math category so i need a lot of help with this.

Answer 5

The heat associated with a certain mass changing temperature is

Answer 6

m*c*(dT)

Answer 7

the energy change in the water has to equal the energy change in the metal

Answer 8

Qm=140*c*(70-10)
Qw=220*4.186*(10-0)

Answer 9

you set the two equal to each other and solve for c. That equation will give units of Joule/(gram Celsius)

Answer 10

so would i be solving the equation that you suggested i'm confused

Answer 11

Have you learned the heat/energy required to change the temperature of a substance?

Answer 12

no i don't quite understand how to solve problems like these.

Answer 13

ok we have the equation Q=mc(dT) where Q is heat, m is mass of whatever is changing temperature, dT is the change in Temperature.

Answer 14

the magnitude of the heat has to be the same for both the metal and the water

Answer 15

so you plug the known values into the heat equation for water and metal and set them equal to each other to find the specific heat you are looking for.

Answer 16

The magnitude of the heat is the same in both due to conservation of energy

Answer 17

so basically what would be the numbers in the equation to plug into the problem if is the same.

Answer 18

Your final equation would look like:
140*c*(70-10)=220*4.186*(10-0)
140*60*c=220*10*4.186

Answer 19

and you want to find c in J/gC

Answer 20

so how would i find c

Answer 21

140*60*c=220*10*4.186

8400*c=9209.2

c=9209.2/(8400)

c=1.1 J/gC

Answer 22

1.0963 would be c

Answer 23

yeah

Answer 24

so what units should i use for this problem?

Answer 25

that c is J/(gC) or Joules per gram degree Celsius

Answer 26

the energy in Joules it takes to change the temperature of 1 gram of metal 1 degree celsius

Answer 27

so would this be the same as 1.0963 cal/g degree Celsius ?

Answer 28

no 1 cal= 4.186 Joules

Answer 29

if you want calories divide your answer by 4.186

Answer 30

i don't think my answer is right

Answer 31

i have 0.2619

Answer 32

yep I think that's good

Answer 33

why dont you think it is right

Answer 34

i don't know because i think that my units wont match up with the right answer that i just put up there

Answer 35

im not sure what you mean

Answer 36

like should it say 0.2619 cal/g degrees Celsius, does that sound right?

Answer 37

oh yeah those are the units for specific heat

Answer 38

thank you so much I got it right thanks

Answer 39

you're welcome :)