Question

#1: Which of the following statements is true?

A. In an endothermic reaction, the energy of the products is the same as the energy of the reactants.

B. In an endothermic reaction, the energy of the products is less than the energy of the reactants.

C. In an exothermic reaction, the energy of the products is the same as the energy of the reactants.

D. In an exothermic reaction, the energy of the products is less than the energy of the reactants.

***my answer; D

is that right? @aaronq :)

Answer 1

#2: Which of the following equations attached is a correctly written thermochemical equation?

***answer choices A,B,C,D from top to bottom :)

i don't get this one :( what do u think?

Answer 2

1 is good !

Answer 3

#3: Which of the following is likely to be true about the ΔH for this reaction?
C6H6(I) → C6H6(s)

Answer choices A,B, and C from top to bottom :)

***i think it's C, ΔH<0.... is that right? Not toooo sure :/

Answer 4

aweosme!! :D

Answer 5

for 2, theres errors in the format of each one except one.. can you figure it out?

Answer 6

3 is good

Answer 7

#4: Two hundred grams of a substance requires 1.84 kJ of heat to raise its temperature from 25°C to 45°C. Use the table attached to identify the substance. q = mCT. Mass (m) is in grams. Temperature is in degrees Celsius.

A. gold

B. copper

C. iron

D. ethanol

***not very sure :(

Answer 8

yay for 3! and lemme see about 2... :/ i didn't really get it earlier... lemme try again :)

Answer 9

is #2 A? the other ones look similar, but only A is different... is that right? :)

Answer 10

4 is just algebra

1840 J=(200g)C(45-25)

Answer 11

#5: A chemical reaction is carried out in a closed container. The energy absorbed by the chemical reaction is 200 kJ. What is the energy liberated from the air or the walls of the container?

A. 200 kJ

B. 100 kJ

C. 75 kJ

D. 50kJ

**my answer; A

is that right? :)

Answer 12

they look similar, but one is not balanced, and the other the enthalpy change is not written in terms of kJ/mol

Answer 13

5 is good ! :)

Answer 14

ahh :/ wait so i don't understand #2 at all then :( sowwyyy :(

and so how do i do #4? :/

Answer 15

and yay for 5! hahah :P

Answer 16

for 4 you plug your values in:

1840 J=(200g)C(45-25)

isolate C

C=1840/[200(20)]

then look at the table

Answer 17

ohh oaky... sooo i got .46... so the answer is IRON ? :)

Answer 18

for 2, the first one doesn't include the enthalpy change, the third's change in enthalpy is not kJ/mol, and the fourth is not balanced

Answer 19

okay, so #2 is the second one then?

Answer 20

yesss, iron

yes 2 is the second

Answer 21

cuz all the others are missing something?

Answer 22

haha i feel like we did these questions before

Answer 23

aweosme!! :) okay!! thanks!! :D

Answer 24

yeah they felt kinda similar lol :/ but i don't feel like they were the exact same ones haha :/ weird :P

Answer 25

haha thanks!! :D

Answer 26

haha okay! i guess they're just similar concepts


no problem !:)