Suggested Solutions - DONE

[Synesthetic]

6c...
the step from reactant to products actually consumes slightly more energy than is released from products to reactants.

so you'd have a net gain of CO2 actually.

My understanding was, the question involves the production of methanol by electrolysis (thus consuming CO2), balanced against its subsequent use in combustion engines (thus producing CO2) => overall carbon neutrality.

[monicak]

17)
From the given equations you can determine that the Cr3+ reduction equation lies below Co2+ and above Fe2+, because Cr2+ reduces Co2+, and Cr3+ oxidises Fe
Pb2+ is above Co2+ hence Pb2+ reacts spontaneously with Cr2+
None of the other choices result in a spontaneous reaction

Thank you

[bucket]

6c...
the step from reactant to products actually consumes slightly more energy than is released from products to reactants.

so you'd have a net gain of CO2 actually.

My understanding was, the question involves the production of methanol by electrolysis (thus consuming CO2), balanced against its subsequent use in combustion engines (thus producing CO2) => overall carbon neutrality.

I wrote the same thing =\

[Pandemonium]

well i don't know am i wrong?

[riadnicolas]

6c...
the step from reactant to products actually consumes slightly more energy than is released from products to reactants.

so you'd have a net gain of CO2 actually.

My understanding was, the question involves the production of methanol by electrolysis (thus consuming CO2), balanced against its subsequent use in combustion engines (thus producing CO2) => overall carbon neutrality.

wasnt it just about methanol production in fuel cell

[doboman]

i thought it was getting rid of CO2

[Synesthetic]

3b was which one had more than one proton didn't it?
well we know that the [acid] was all 0.1M
therefore, assuming complete ionisation of the acid, we'd have [H+] = 0.1M
pH would therefore be equal to 1 at the minimum if it were monoprotic.
acid III i think had pH 0.7, therefore it had to be at least diprotic.

(from the other thread)

Thanks, that sounds like the required explanation!

[nathankb]

where are mao's answers to section b??

[bucket]

i thought it was getting rid of CO2

Yeah but then the methanol was used in a combustion engine, hence producing more CO₂.

[Synesthetic]

6c...
the step from reactant to products actually consumes slightly more energy than is released from products to reactants.

so you'd have a net gain of CO2 actually.

My understanding was, the question involves the production of methanol by electrolysis (thus consuming CO2), balanced against its subsequent use in combustion engines (thus producing CO2) => overall carbon neutrality.

wasnt it just about methanol production in fuel cell

Oh - yeah, it WAS a fuel cell wasn't it...

i thought it was getting rid of CO2

CO2 was on the reactants side of the equation producing methanol

[monicak]

I said it was neutral, since 1 mol of methanol produced 1 mol of CO2 in the combustion and 1 mol of CO2 was used to produce 1 mol of methanol...

[charm]

I said it was neutral, since 1 mol of methanol produced 1 mol of CO2 in the combustion and 1 mol of CO2 was used to produce 1 mol of methanol...

yes me too...

[riadnicolas]

6c...
the step from reactant to products actually consumes slightly more energy than is released from products to reactants.

so you'd have a net gain of CO2 actually.

My understanding was, the question involves the production of methanol by electrolysis (thus consuming CO2), balanced against its subsequent use in combustion engines (thus producing CO2) => overall carbon neutrality.

wasnt it just about methanol production in fuel cell

Oh - yeah, it WAS a fuel cell wasn't it...

i thought it was getting rid of CO2

CO2 was on the reactants side of the equation producing methanol

wat did the question say exactly?

[bucket]

Something like what was the overall affect on the atmospheric CO2 concentration.

[Mao]

6c...
the step from reactant to products actually consumes slightly more energy than is released from products to reactants.

so you'd have a net gain of CO2 actually.

My understanding was, the question involves the production of methanol by electrolysis (thus consuming CO2), balanced against its subsequent use in combustion engines (thus producing CO2) => overall carbon neutrality.

wasnt it just about methanol production in fuel cell

Oh - yeah, it WAS a fuel cell wasn't it...

i thought it was getting rid of CO2

CO2 was on the reactants side of the equation producing methanol

wat did the question say exactly?

what's this about fuel cell...? i don't see it on that page at all

just "electrolytic cell"