Some people don't understand Chemistry..I'm one of them?

[Kamage]

Yeah, well, I'm not quite understanding these problems,:

1)How much heat is neede to raise the temperature of 20 grams of water from 20C to 120C

2)170 cal. of heat is needed to increase the temperature of 16.7 cm^3 Hg from 40 C to 60C. The density of Hg is 13.6 g/cm^3, what is the specific heat of Hg?

3)How much heat is needed to transform 10g of water from -20C to 30C?

4)How much heat is needed to raise the temperature of 30 cm^2 of copper from 10C to 40C. The density of copper is 8.94 g/cm. While the specific heat is 0.092 cal/gC

5)200 calories of heat is needed to increase the temperature of 19.8 cm of metal from 20 degrees to 40 degrees. The density of the metal is 11.98 g/cm, determine the specific heat of metal.

6)One pac of cereal gives 230 cal. of energy on oxidation. How much kg of water can be heatedfrom 15 C to 40 C by burning the cereal?


**Okay, well as you can see, I am stumped, all I know is that you use some formulas, like:

H=mHf
H=mHv
H=Mc[]t