1Question
A chemical reaction releases 50 J of energy. What type of reaction is this: exothermic or endothermic?
2Question
A process absorbs 80 J of energy from the surroundings. What type of process is this?
3Question
If 120 J of energy is added to a system, how much energy did the system gain?
4Question
A student measures 30 J of heat released by a reaction. What is the sign of q for the reaction?
5Question
A reaction absorbs 200 J of heat. What is the sign of q?
6Question
How much energy is transferred if a reaction releases 15 J and then releases another 25 J?
7Question
A system absorbs 60 J and later releases 10 J. What is the net energy change?
8Question
If a reaction has an enthalpy change of -90 J, does it release or absorb energy?
9Question
A reaction has an enthalpy change of +75 J. Is the reaction exothermic or endothermic?
10Question
A reaction releases 100 J of energy. What is its enthalpy change, ΔH?
11Question
A reaction absorbs 140 J of energy. What is its enthalpy change, ΔH?
12Question
A sample gains 250 J of heat. If no other energy changes occur, what is the energy change of the sample?
13Question
A reaction starts with 500 J of energy in the reactants and 620 J in the products. What is ΔH?
14Question
A reaction starts with 900 J in the reactants and ends with 780 J in the products. What is ΔH?
15Question
If a reaction absorbs 300 J, how much energy must the surroundings lose?
16Question
If 45 J of heat is released to the surroundings, how much heat does the system lose?
17Question
A reaction releases 55 J and another part of the same process absorbs 20 J. What is the net energy change?
18Question
A reaction absorbs 90 J and then absorbs 30 J more. What is the total energy absorbed?
19Question
If a reaction has ΔH = -210 J, how much heat is released?
20Question
If a reaction has ΔH = +260 J, how much heat is absorbed?
21Question
A reaction releases 400 J of energy in total. If 150 J is released in the first step, how much is released in the second step?
22Question
A process absorbs 500 J over two steps. If the first step absorbs 180 J, how much does the second step absorb?
23Question
A reaction has reactants at 1000 J and products at 1150 J. How much energy is transferred, and in which direction?
24Question
A reaction has reactants at 850 J and products at 700 J. How much energy is transferred, and in which direction?
25Question
A student heats a system and the system absorbs 75 J. Later it absorbs 25 J more. What is the total energy change?
26Question
A reaction releases 200 J, but 60 J is used up by another part of the process. What is the net energy released?
27Question
A reaction absorbs 180 J. If 40 J is lost to the container, what is the net energy absorbed by the reaction?
28Question
In a reaction, the products have 50 J more energy than the reactants. What is ΔH?
29Question
In a reaction, the products have 300 J less energy than the reactants. What is ΔH?
30Question
A reaction absorbs 220 J in one step and releases 80 J in another step. What is the overall energy change?