Question

#1: You have a series of four chemical reactions (1 --> 2 --> 3 --> 4). How do you calculate the (triangle) H2 if you know the other (triangle)H values?

Answer 1

A,B,C,D from top to bottom for #1 :)

**my answer: C

is that right?

Answer 2

haha you can abbreviate "triangle" for d

dH = delta H

Answer 3

hey aaronq pleaseeeeeee help e I posted several questions

Answer 4

hey don't ask about your questions in other peoples questions

Answer 5

#2: See attachment!

What is the delta H ?


A. -594 kJ

B. -198 kJ

C. +198 kJ

D. +792 kJ

**My answer: A

is that right?

hehe i seee :) thanks for that tip! :D

Answer 6

il look at in a sec though

Answer 7

#3: How much heat is given off when 32 g liquid methanol (CH3OH) at its freezing point changes to solid methanol? (methanol delta Hf = 3.16 kJ/mol)

A. 0.18 kJ

B. 3.16 kJ

C. 1.58 kJ

D. 0.79 kJ

***My answer; B

is that right?

Answer 8

2 is not right, you're reversing the second one to match the last equation

so -792 + 594

Answer 9

#4: What is the change in enthalpy when 250 g of water vapor condenses at 100oC? (delta Hv = 40.67 kJ/mol)

A. - 565 kJ
B. - 291 kJ
C. 291 kJ
D. 565 kJ

***my answer: A

is that right? :)

OMG the delta thing is soooo handy!! :D

Answer 10

so #2 is B. -198 kJ ??

what about 1? :D

Answer 11

i think you're right for number 1, but I've never seen that

Answer 12

#5: This diagram attached would represent the enthalpy changes in which of the following?

A. boiling liquid

B. cold pack

C. melting solid

D. hot pack
**my answer: D. hot pack

is that right?

Answer 13

haha oaky! was #2 B then? :)

Answer 14

3-5 are good :)


d is so handy, i know

Answer 15

oh wait haha you already said 3-5 were good lol my bad!! :D haha thanks!! :D and #2 was B?? @aaronq :)

Answer 16

haha :P yeah 2 is B

Answer 17

haha thanks! :D

Answer 18

no problem :)