posted by .

1)A piece of metal with a mass of 5.50 grams changed in temperature from 25 to 55 degrees celsius when 21.3 joules was absorbed. What is the specific heat of the metal?

a)0.256
b)0.129
c)3.91
d) 7.75
e)0.710 Jg^-1 C^-1

I chose 7.75 because I did 5.50/21.3 and then multiplied by 30.

2)Which of the following equations represents a reaction for which the delta H can be called a standard enthalpy of formation, delta Hf?

a) FeO(s) + CO2(g) -> FeCO3(s)
b) 1/2 N2(g) + 2 O(g) -> NO2(g)
c) 2 Na(s) + Cl2(g) -> 2 NaCl(s)
d) Ba(s) + N2(g) + 3 O2(g) -> Ba(NO3)2(s)

e) more than one of the four equations above are standard enthalpies of formation.

Are these correct?

1.
21.3 = mass x sp.h. x delta T
sp.h. = 21.3/(5.50*30) is not 7.75.

2.
I agree with d.

Ok for number one i got 0.129 and for number 2 did you mean that my answer choice of e was correct or that just equation d is correct? Thank you for your help!!

## Similar Questions

2. ### chemistry

3.) A 5.00 x 10^2 g block of metal absorbs 5016 joules of heat when its temperature changed from 20 degrees C to 30 degrees C. Calculate the specific heat of the metal. I used the formula and came with two answers 100.32 joules and …
3. ### Chemistry

The specific heat of copper metal was determined by putting a piece of the metal weighing 33.6 g in hot water. The quantity of heat absorbed by the metal was calculated to be 47 J from the temperature drop of the water. What was the …
4. ### Chemistry

The specific heat of copper metal was determined by putting a piece of the metal weighing 33.6 g in hot water. The quantity of heat absorbed by the metal was calculated to be 47 J from the temperature drop of the water. What was the …
5. ### AP Chemistry

A 500 g piece of metal at 60 degrees celsius is placed in 200g of water at 22 degrees celsius contained in a coffee cup calorimeter. The metal and water come to the same temperature at 32.5 degrees cesius. The specific heat of the …
6. ### Chemistry

The specific heat of copper metal was determined by putting a piece of the metal weighing 39.4 g in hot water. The quantity of heat absorbed by the metal was calculated to be 47 J from the temperature drop of the water. What was the …
7. ### chemistry

A piece of metal with a mass of 5.50 grams changed in temperature from 25.0 to 55.0C when 21.3 joules was absorbed. The specific heat of the metal is a. 0.256 b. 0.129 c. 3.91 d. 7.75 e. 0.710J g-1 oC-1 desperately need help!
8. ### chemistry

* A 50 gram sample of an unknown metal warms from 18 to 58 after absorbing 800 joules of energy. what is the specific heat of the metal?
9. ### Chemistry

A 11.6 g sample of an unknown metal was heated to 100.0 oC and then added to 25.0 g of water at 23.0 degrees Celsius in an insulated calorimeter. At thermal equilibrium, the temperature of the water in the calorimeter was 24.8 degrees …
10. ### Science

A piece of unknown metal with a mass of 68.6 grams is heated to an initial temperature of 100 Celsius and dropped into 42 grams of water with an initial temperature of 20 Celsius in a calorimeter the final temperature of the system …

More Similar Questions