Question

In general, spontaneous reactions are different than non-spontaneous reactions in that spontaneous reactions:

must use a catalyst to progress at a reasonable rate

can provide free energy that can be used for work elsewhere

create a large decrease in entropy

only occur at very high temperatures

Given 28.2 grams of an unknown substance, if the substance absorbs 2165 joules of energy and the temperature increases by 35 Kelvin, what is the specific heat of the substance?

2.14 x 106 J/g·K

2.19 x 100 J/g·K

5.73 x 10-4 J/g·K

2.69 x 103 J/g·K

A substance of unknown mass a

Answer 1

A substance of unknown mass absorbs 138 kilojoules of energy, going from 298 to 303 Kelvin. If the specific heat of the substance is 7.11 J/g·°C, how much of the substance was present?

3.88 kg

32.3 g

3.88 g

32.3 kg

Which of the following will not favor a spontaneous change?

+ΔS
−ΔS
+ΔH
−ΔH



II only

II and III

III only

I and II

Answer 2

That's a lot of questions. Why don't you post one by one?