Question

Question #1aff0

Answer 1

The thermochemistry base equation is `Q=mC_pT` where
Q = Heat in Joules
m = mass of the material
* `C_p` = specific heat capacity

T = change in Temperature `T_f - T_i`

• For this equation the metal is going to lose heat make Q negative while the water is going to gain heat making Q positive

Due to the Law of Conservation of Energy the heat lost by the metal will be equal to the heat gained by the water.

• `-Q_(Cr) = +Q_(water)`

specific heat of water is 4.18 J/gC
specific heat of iron is 0.45 J/gC
We will assume that water boils at 100 C and that is the initial temp of the chromium.

`-[25.0g(T_f - 65.4C) (0.45J/gC)] = 100.0g(T_f - 20.0C) (4.18J/gC)`
`-11.25T_f + 735.75 = 418.0T_f - 8360.0`
`9,095.75 = 429.25T_f`
`21.19 C`

I hope this was helpful.
SMARTERTEACHER