whats the answer?

[lacoste]

QUESTION 2
Consider the following reaction: 2NO(g) + O2(g) →2NO2(g) ΔH = −114kJ /mol
The amount of energy released during the complete reaction of 1.00 L of nitrogen monoxide
at 0^oC and 101.3 kPa is:
A 114 kJ
B -114 kJ
C 2.54 kJ
D -2.54 kJ

I got D why is it meant to be C

[d0minicz]

its asking for the amount of energy released not delta H

[methodsboy]

yeah i got C. You didnt do this:
E= (114 / 2) x n(NO)
u forgot the coefficient of NO, which is 2

working:
E = (114kJmol / 2 ) x 2.545mol = 2.54 kJ

[lacoste]

Nah methodsboy did the exact steps as you, but you omitted the -ve sign.

I need to read more slowly and carefully since it asked for energy.

cheers all.


Another Q, when writing  the equm expression do we have to include states ?

[lacoste]

QUESTION 20
300 ml of a 0.35 M Ca(OH)2 solution was reacted with 300 ml of 0.40 M HCl .
The pH of the resultant solution is closest to:

A 0.82
B 1.12
C 12.88
D 13.18

[lacoste]

QUESTION 20
300 ml of a 0.35 M Ca(OH)2 solution was reacted with 300 ml of 0.40 M HCl .
The pH of the resultant solution is closest to:

A 0.82
B 1.12
C 12.88
D 13.18

nvm gottttttttttttt it!!:)

[methodsboy]

Nah methodsboy did the exact steps as you, but you omitted the -ve sign.

I need to read more slowly and carefully since it asked for energy.

cheers all.


Another Q, when writing  the equm expression do we have to include states ?

oh yeah. sorry i should NOT have put in the negative in the working out..it just confuses. ill just edit that.