Chemistry Help HERE ONLY !!

[heat619]

u guys...help me with this question..
ppr3 june 04 7 b) ii

can someone answer tht
i need help with that too

to find which is in excess we have to compare moles and see which one has more, this will be excess.
Moles of Mg=3/24=0.125
Moles of Ethanoic acid= 12/60=0.2
So now u may think that ethanoic acid is excess.
But look at the mole ratios in the formula, it says (1)Mg + 2 ethanoic acid
so u hav to divide moles of acid by 2 so u get 0.1, so with the same ratios, mg has more mole(0.125),so its in excess....

[kam]

i was talking about bii
how many moles of hydrogen formed

and thx By the way
+rep 4 u

[evilzurg307]

Can any one explain the answer to O/N 2008 q4(a)(iii)??

4(a)(iii)Name two compounds (other than sodium hydroxide) that would react with benzoic acid to form sodium benzoate?
A: Sodium oxide and Sodium Carbonate but why???

[kam]

acid+base= salt + water
acid+carbonate=salt + water +carbon dioxide
as the oxide is basic
the salt is sodium benzoate
gettit?
i just hope im right
correct me if im wrong tho

[heat619]

i was talking about bii
how many moles of hydrogen formed

and thx By the way
+rep 4 u

ohh srry lol
k, use mole ratio, if 2 moles gave u 0.2 mol, then 1 mole would give u X
X= (0.2*1)/2
X=0.1

[evilzurg307]

acid+base= salt + water
acid+carbonate=salt + water +carbon dioxide
as the oxide is basic
the salt is sodium benzoate
gettit?
i just hope im right
correct me if im wrong tho

Oh i see
I dint know sodium benzoate was a salt lol

[kam]

acid+base= salt + water
acid+carbonate=salt + water +carbon dioxide
as the oxide is basic
the salt is sodium benzoate
gettit?
i just hope im right
correct me if im wrong tho

Oh i see
I dint know sodium benzoate was a salt lol

i may be wrong tho

[kam]

i need help in nov 2004 q7
c)

[THEIGBOY]

i need help in nov 2004 q7
c)

number of moles of Fe2(SO4)3 = 1/40 or 0.025
number of moles of Fe2 O3 formed = 1/40 or 0.025
mass of iron(III) oxide formed = 0.025 x 160 = 4g
number of moles of SO3 produced = 3/40 or 0.075
volume of sulphur trioxide at r.t.p. = 0.075 x 25
                                               = 1.8dm³
hope it helps



By the way guyz my rep got reduced.... may i know who did it and why?

[reishamix]

hey
can sm1 plz attatch the mark scheme
fr o/n session 2003 chemistry paper 3??
 

[THEIGBOY]

hey
can sm1 plz attatch the mark scheme
fr o/n session 2003 chemistry paper 3??
 

which year?

[THEIGBOY]

argh...sumbudy decreased my rep even more

[reishamix]

argh...sumbudy decreased my rep even more

frget rep man
it dsnt mke a differnc
do u hav the mark scheme??

[THEIGBOY]

argh...sumbudy decreased my rep even more

frget rep man
it dsnt mke a differnc
do u hav the mark scheme??

Which year?
i have all marking schemes from 1999 onwards

[reishamix]

argh...sumbudy decreased my rep even more

frget rep man
it dsnt mke a differnc
do u hav the mark scheme??

Which year?
i have all marking schemes from 1999 onwards

2003