help with any pf these questions?

Question

can anyone plz help me w/ any of these. im not looking for fast, easy answers, i want to see how to solve, so i can apply the same procedure to any similar questions. my textbook doesnt offer any help, and my chem teacher sucks...
also, does anyone know of a site i can go 2 that will help?
thx so much, help is really appreciated! :)

1. How many kilojoules are required to raise the temperature of 4.55 x 10 *2* ml of water from 22.4 C to 300 K?

2. When 8.78 x 10 *2* J of heat are absorbed by 1.25 x 10 *2* grams of silver from 25.0 C to 54. 9 C. What is the specific heat of silver?

3. A copper wire weighing 3.16 g absorbs 42.8 J of heat. If its initial temperature is 22.6 C, what is its final temperaure? The specific heat capacity of copper is 0.385 J/g C.

*2* means "squared"


thanks a lot!

Answer 1

for each question you need the formula for calculating and energy change - the formula is:
energy = (mass)(temp change)(specific heat)

1) energy = (455 g)(4.6 C)(4.184 J/g C)
energy = 2100 J = 2.1 kJ

2) 878 J = (125 g)(29.9)(spec heat)
0.235 J/g C = spec heat

3) 42.8 J = (3.16 g)(temp change)(0.385 J/g C)
35.2 C = temp change
22.6 C + 35.2 = 57.8 C

Answer 2

i went out final nighttime yet i did no longer drink i felt like a loser i took the day without work purely so i'm going to have exciting and that i became into domicile at 11:30 yet i assume its ok cuz I could awaken at 6 for paintings this morning

Answer 3

1. 1mL H2O = 1g H2O 300K=27C 27.0C-22.4C=4.6degC difference

4.55x10^2gH2O x 4.6degC x 1cal/g-degC x 4.184kJ/1000cal = 8.75kJ

2. 54.9C-25.0C=29.9degC difference

(878J)/(125gAg)(29.9degC) = 0.234J/g-degC