Question

#1: What is the difference between an exothermic and an endothermic reaction?

A. Endothermic reactions release heat.

B. There are no changes in heat during either reaction.

C. Exothermic reactions absorb heat.

D. Endothermic reactions absorb heat.

***my answer: D

is that right? @aaronq ?

Answer 1

#2: Which of the following is an endothermic process?

A. rusting a nail in water

B. dissolving acetic acid in water

C. mixing strong hydrochloric acid and strong ammonium hydroxide

D. melting ice in water

**my answer: D
is that right? :)

Answer 2

#3: Air flows according to differences in thermal energy. If a warm air mass is located in the northwest United States and a cold air mass is located in the southeast United States, from which direction will the winds blow?

A. northwest

B. southeast

C. southwest

D. northeast

**my answer: B. southeast

is that right?

Answer 3

1 and 2 are good

Answer 4

3 is good

Answer 5

#4: Two liquids of different temperatures are separated by a barrier. The hot liquid is on the right side and the cold one is on the left side. Which of the following describes how the molecules move in heat flow?

A. Molecules from the left collide and transfer heat to the barrier, which transfers heat to the right side.

B. Molecules from the right collide and transfer heat to the barrier, which transfers heat to the left side.

C. Molecules from the left collide and transfer heat directly to the right side.

D. Molecules from the right collide and transfer heat directly to the right side.

**my answer: A

is that right? :)

Answer 6

ooh yay!! :)

Answer 7

#5: A chemical reaction is carried out in a closed container. The energy absorbed by the chemical reaction is 150 kJ. How much thermal energy moves inward from the air or the walls of the container?

A. 75 kJ

B. 100 kJ

C. 150 kJ

D. 200 kJ

***my answer: B. 100 kJ

is that right? =) @aaronq

Answer 8

4 is not right

Answer 9

i think you messed up the sides

Answer 10

5 is not right either, where did the other 50kJ come from :P

Answer 11

oh darn :(

so should #4 be B then?

and idk #5 then :( how do u do #5 then?

Answer 12

ohhh wait! should #5 be C. 150 kJ then? @aaronq ? :)

Answer 13

is that right?

Answer 14

yep! the heat transferred has to be equal. otherwise where would it come from? :P

Answer 15

haha awesome :)

and wait so was #4 B? not A? @aaronq ?

Answer 16

yep, heat flows from hotter to colder, the right was hotter than the left

Answer 17

kk awesome! thanks :)

Answer 18

no problem :)