Question

#1: One hundred grams of a solid substance is heated to a gas and higher. According to the graph attached inside, in what phase are the molecules moving most rapidly?

E, A, C or B?

**my answer: E

not too sure though.. what do u think @aaronq :)

Answer 1

graph for #1! :)

Answer 2

#2: If 4.5 kJ of energy is removed from 100 g of aluminum that has a beginning temperature of 100°C, what is the final temperature in degrees Celsius?

***USE THE ATTACHED TABLE!!! *** :)

A. 25

B. 50

C. 100

D. 150

***im not very sure... :( what do u think? :)

Answer 3

yep! kinetic energy = movement

average kinetic energy = temperature

Answer 4

so that means #1 is right? :) it's letter E? :)

Answer 5

#2: If 4.5 kJ of energy is removed from 100 g of aluminum that has a beginning temperature of 100°C, what is the final temperature in degrees Celsius?

q=4.5kJ
m=100g
T1=100
C=0.9

4500=0.9*100*(T2-100)

T2=4500/[0.9*100] +100

Answer 6

yes #1 was E

Answer 7

#4: In the diagram attached, which letter represents the heating of a solid?

A, B, C, or D?

**My answer; D

im not too sure though.. is that right? :)

Answer 8

so #2 is D. 150? :)

Answer 9

for 3, q=H, in this case

Answer 10

so it's just like any other problem

Answer 11

#5: The reaction in the diagram attached takes place in an ice calorimeter at 0°C. What happens to the ice?

A. The ice gets colder.

B. The temperature of the ice stays the same.

C. Some ice melts.

D. You cannot tell from the information given.

**my answer; A. The ice gets colder.

but I'm not too sure... is that right? :)

Answer 12

#4 nope, the solid would exist at the lowest temperature

Answer 13

so would q=20? for #3?

Answer 14

so is #4 B then?

Answer 15

#5 is good

Answer 16

#4 B would be melting the solid into a liquid

Answer 17

so does the solid have to be the straight lined ones ? or while its rising up? :/

Answer 18

and so #2 was D. 150 right? :)

Answer 19

and yay for #5 :)

Answer 20

#2 is 150
#3 should be 104.. ill let you decide whether it's negative or positive :P

Answer 21

#4 is A btw

Answer 22

oaky... ermm idk how to figure out if its pos or neg.. :/ how can i determine that? :/

Answer 23

should it be positive 104? since all the other components of that question are positive numbers? :/

Answer 24

look at the temperature change

Answer 25

ohh i see.. so it's going up right? so it should be +104 then?

Answer 26

since the temp went from 10 to 50?

Answer 27

yep!

Answer 28

awesome!!! :) thank youuu :) lol that makes sense! so if it were going from 50 to 10, that would be a negative answer right?

Answer 29

yeah, you're giving energy off to the surroundings (temp is decreasing) so its exothermic, right? meaning dH will be negative.

Answer 30

ahh okay! that makes sense :) thanks a bunch!!!!

Answer 31

no problem :)