[jaysup_2006]

I am not sure what equation or equations to use for this problem:

A 112 g sample of copper (specific heat capacity = 0.20 J °C-1 g-1) is heated to 85.1°C and then placed in a container of water at 22.3°C. The final temperature of the water and copper is 25.1°C. What is the mass of the water in the container, assuming that all the heat lost by the copper is gained by the water?

I think I use this one, because T-final is given for both, and only unknown is mass of water,(heat capacity of water is contant right, 4.184, i think?)  +(mc?T)copper  =  ?(mc?T)

[allanf]

Yes, thats the right equation.  The problem is one of simple conservation of heat, so all you have to do is re-arrange for the mass of water and plug-in the right numbers.

[jaysup_2006]

so, would my equation look like..

(112g)(.20)(25.1-85.1)= -[(x)(4.184)(22.3-25.1)]

[allanf]

looks good to me.  a quick in my head calculation would say the mass of water is around 115g.

[jaysup_2006]

Yup, I worked it out to 114.722, I have to go by significant figures though, which is two, so it gets rounded to 110
(i hate sig figures) Thanks for all the help