# Homework Help: Laboratory technician drops a 0.0850kg sample of unknown solid

1. Sep 20, 2009

### Larrytsai

A laboratory technician drops a 0.0850kg sample of unknown solid material, at a temperature of 100.0 degree celcius, into a calorimeter. The calorimeter can, initially at 19.0 degrees celcius, is made of 0.150kg of copper and contains 0.200kg of water. The final temperature of the calorimeter can and contents is 26.1 degrees celcius. Compute the specific heat of the sample.

The only thing i have so far is

Qsys= -Qsurr
but im stumped with the 2 specific heat variables

2. Sep 21, 2009

### Staff: Mentor

Re: Thermodynamics

Not sys and surr, I would rather go for gain=lost.

I suppose you should check both specific heats of copper and water in tables.

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3. Sep 25, 2009

### epenguin

Re: Thermodynamics

Being calories and degrees C he ought to know that for water roughly.

4. Oct 22, 2009

### traffic_boy

Re: Thermodynamics

i'll be so grateful if you can help me for this problem:
a 30.14-g stainless steel ball bearing at 117.82 c is placed in a constant-pressure calorimeter containing 120.0 mL of water at 18.44 C.if the specific heat of the ball bearing is 0.474 J/g.c, calculate the final temperature of the water.assume the calorimeter to have negligible capaity.

5. Oct 22, 2009

### Staff: Mentor

Re: Thermodynamics

It is again simple heat gain (by water) equals heat lost (by ball). Assume final temperature to be Tfinal and write equation for a heat balance. You will get equation with one unknown. That's all.

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methods

6. Oct 24, 2009

### traffic_boy

Re: Thermodynamics

thank you so much,,i got the idea, but i'm still thinking about if q(water) equals q(ball), can we
prove that (Delta Temp) for water equals (Delata Temp) for the ball!!!!!

7. Oct 24, 2009

### PhaseShifter

Re: Thermodynamics

No, but both changes in temperature are directly proportional to the amount of heat transferred.