[hitleap]

I have some questions about thermochemistry. Thanks in advance~

1: During a chemical reaction, chemical energy may be:
a) released as heat
b) converted to work or other forms of energy

I think it it is "A" am I correct?

2: How much heat is needed to raise the temperature of 10.0 g of aluminum metal by 10 degrees celcius? (Cp for aluminum is 24.4 J/(mol*degrees celcius)

a) 90.4J
b) 2.44kJ

I think it is "B" because 10*10*24.4 = 2440=2.44kJ

3: A spontaneous reaction is one which ___

a)does occur
b)occurs at a rapid rate

I think it is "B"

4: Which of the following is reponsible for teh fact that the metling of ice is a spontanoeus process at room temperature and standard pressure?

a) melting is accompanied by a decrease in entropy
b) melting is accompanied by a increase in entropy
c) melting is accompanied by a increase in energy
d) melting is accompanied by a decrease in energy

I think it is "B"

thanks!

[vmelkon]

For 1, it would be b in the general case. For example, some chemicals might detonate so some of the energy is in the form of kinetic, audio, heat, light.

For 2, you should pay attention to units. Your quantity of Al is in grams and look at the Cp.

For 3, why do you think it is b?

[hitleap]

For 1, it would be b in the general case. For example, some chemicals might detonate so some of the energy is in the form of kinetic, audio, heat, light.

For 2, you should pay attention to units. Your quantity of Al is in grams and look at the Cp.

For 3, why do you think it is b?

Lol, I was trying to post the wrong answer, because whenever I write the correct answer (even though I guess sometimes) I am always right. It was just weird.
just to confirm:
It is B, A, A, B?
the last one is B right?

Thanks once again!!

[vmelkon]

Looks correct.