i need help from all you chemistry geniuses

[larciel]

i got stuck on prob.

if you have nothing to do, help would be appreciated.

"a 100-g iron ball (specific heat = 0.473j/g C ) is heated to 125C and is placed in a calorimeter holding 200 g of water at 25.0 C . what will be the highest temperature reached by the water?

answer is 30.4 C but don't know how da heck i can get it

thanks in advance

 

[Dark4ng3l]

Just calculate total energy than use that to find your answer.

 

[His Lord Uberdude]

42

 

[larciel]

what total energy? of water?

 

[vi edit]

You need to look up specific heat of water.

 

[hjo3]

Originally posted by: vi_edit
You need to look up specific heat of water.

Yeah, that 1 cal/g°C figure is pretty hard to remember.

 

[Jmman]

Originally posted by: vi_edit
You need to look up specific heat of water.

I think this is something that most chemistry students memorize, no?

1 calorie/gram °C = 4.186 joule/gram °C

Oh, by the way, some of these calorimetry problems can be a pain in the bunghole....

I am glad I have done my chemistry "time".......

 

[larciel]

yeah i forgot, specific heat of water is 4.186 j /g C

so who knows the equation to solve the prob?

 

[jagec]

Dude, just do an energy balance.

 

[Lenine]

Qhot=-Qcold
mdeltaTc=-(mdeltaTc)

 

[DrPizza]

Don't rely on memorizing an equation... try to figure out an equation to use...
Something like... heat before equals heat after?

 

[Lenine]

0.1*(x-125)*specific heat of iron=-(0.2*(x-25)*4200)

 

[TuxDave]

Originally posted by: larciel
i got stuck on prob.

if you have nothing to do, help would be appreciated.

"a 100-g iron ball (specific heat = 0.473j/g C ) is heated to 125C and is placed in a calorimeter holding 200 g of water at 25.0 C . what will be the highest temperature reached by the water?

answer is 30.4 C but don't know how da heck i can get it

thanks in advance

T = final temperature

100g*0.473j/g*(125-T)=200g*4.718j/g*(T-25)

Heat lost by the ball = Heat gained by the water. Remember, if all else fails, do energy balance.