help

[bravegirl123]

http://papers.xtremepapers.com/CIE/...d AS Level/Chemistry (9701)/9701_w05_qp_1.pdf
In question 12, my answer comes A which is wrong. How can the answer be D?

 

[gary221]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_w05_qp_1.pdf
In question 12, my answer comes A which is wrong. How can the answer be D?

no the ans has to be D
when Mg is burned with O2 ----> MgO is formed, so ratio of O2:Mg = 1:1
when Al is burned -----> Al2O3 is formed, so ratio of O2:Al = 1.5:1
when S is burned ----> SO3 is formed, so ratio of O2:S = 3:1

Hope i helped.
All credit to Nibz

 

[bravegirl123]

no the ans has to be D
when Mg is burned with O2 ----> MgO is formed, so ratio of O2:Mg = 1:1
when Al is burned -----> Al2O3 is formed, so ratio of O2:Al = 1.5:1
when S is burned ----> SO3 is formed, so ratio of O2:S = 3:1

Hope i helped.
All credit to Nibz

doesnt sulphur burn in oxygen to form SO2?

 

[Aries_95]

doesnt sulphur burn in oxygen to form SO2?

Sulphur burns in EXCESS of oxygen to from SO3
It says exceess of oxygen in th question

 

[bravegirl123]

Sulphur burns in EXCESS of oxygen to from SO3
It says exceess of oxygen in th question

but that is a catalysed rxn right?

 

[syed1995]

Sulphur burns in EXCESS of oxygen to from SO3
It says exceess of oxygen in th question

No.. It forms SO2.. That's why that question was cancelled. You can check the Examiner Report... since the formation of SO3 is a reversible reaction a equilibrium is formed and SO2 isn't converted into SO3.

It requires a V2O5 catalyst and certain conditions for this reaction to occur..

 

[Aries_95]

No.. It forms SO2.. That's why that question was cancelled. You can check the Examiner Report... since the formation of SO3 is a reversible reaction a equilibrium is formed and SO2 isn't converted into SO3.

It requires a V2O5 catalyst and certain conditions for this reaction to occur..

Oh...thanks for the help
bravegirl123: sorry