Monday

October 20, 2014

October 20, 2014

Posted by **Debra** on Sunday, October 23, 2011 at 12:56am.

2. A 300 g piece of aluminum is heated from 30 degrees C to 150 degrees C. What amount of heat energy is absorbed?

3. Determine the temperature change in each of the following.

(a) 10 kg of water loses 232 kJ of heat energy.

(b) 500 g of copper gains 1.96 kJ of heat energy.

4. After 2 kg of mercury gained 2.52 x 10^4 J of heat energy, its final temperature was 130 degrees C. What was its initail temperature?

- Science -
**Jai**, Sunday, October 23, 2011 at 2:27amrecall that heat absorbed or released is given by

Q = mc(T2 - T1)

where

m = mass (in kg)

c = specific heat capacity (in J/kg-K)

T = temperature (in C or K)

*note: Q is (+) when heat is absorbed, and (-) when heat is released.

#1. we just substitute. the c for water is equal to 4.184 J/kg-K (you can google this or look for this in books):

Q = mc(T2-T1)

Q = 3*4.184*(10-80)

Q = -878.64 J

*note that it is negative since it cooled, and thus released heat.

#2,3 and 4: just substitute the given values and solve for the unknown. be careful with units.

hope this helps~ :)

**Answer this Question**

**Related Questions**

Physics 20 - 1. How much heat energy is required to change 500 grams of water at...

Science - How much energy is released when a 5600-g sample of water cools from ...

Physics - Please Help! I am having difficulties grasping these concepts. Explain...

AP Chemistry - A 500 g piece of metal at 60 degrees celsius is placed in 200g of...

Chemistry - Calculate the joules of energy involved when 11 grams of water at 10...

Lauren - The specific heat of water is at 4.184J/g * degree C. How much heat is ...

thermal energy - A hot 0.25-kg piece of iron is placed in a calorimeter ...

Science-Chemistry - A 5.00 g sample of Al pellets (specific heat = .89 J/g ...

chemistry - How much energy must be put into a system to raise 100 g of solid ...

chemistry - how much energy is released when a 5600-g sample of water cools ...