Chemistry: Post your doubts here!

[princess Anu]

Q1; How many isomeric esters, including structural isomers and stereoisomers, can be made with the molecular formula C5H10O2, if methanoic acid is one of the two reactants... I got 4 isomers.. is that correct? options include 2,3,4 & 5


Q2; How many isomers, including structural and stereoisomers, with the formula C4 H8 have structures that include Pi bonding.. I got 4 isomers.. is that correct? options include 1, 2,3 &4

 

[Mathemagical]

Q1; How many isomeric esters, including structural isomers and stereoisomers, can be made with the molecular formula C5H10O2, if methanoic acid is one of the two reactants... I got 4 isomers.. is that correct? options include 2,3,4 & 5


Q2; How many isomers, including structural and stereoisomers, with the formula C4 H8 have structures that include Pi bonding.. I got 4 isomers.. is that correct? options include 1, 2,3 &4

Yes, I got 4 isomers each too.

 

[princess Anu]

Yes, I got 4 isomers each too.

What about alcoholic isomers, including stereo & structural, for C4H10O
I get 4 again options are 3,4,5,6

 

[Mathemagical]

What about alcoholic isomers, including stereo & structural, for C4H10O
I get 4 again options are 3,4,5,6

Yes, I got 4 again too.

 

[princess Anu]

help

 

[Mathemagical]

help

Mr(P) = 31
Mr(P2O5) = 2(31) + 5(16) = 142
In 100 g of fertiliser, there is 30.0% P2O5
That means mass of fertiliser is
= (100/30) * Mr(P2O5)
= (100/30) * 142
= 473.3 g

% of phosphorus in fertiliser is
= (2*31 / 473.3) * 100
= 13.1 %

 

[princess Anu]

Q38..

 

[princess Anu]

..

 

[Autumn98]

if the ans is B..

Thankyou so muuch!

 

[Mathemagical]

..View attachment 54408

If all monomers combine, one molecule of the polymer is formed, which is 1/6.02*10^23 moles. The theoretical range is between 1 and 1/6.02*10^23, but it cannot be 1.

 

[qwertypoiu]

Q38..

Is it A?

 

[Choi WW]

The answer is A

I believe that phosphoric acid is a weak acid, so is the phosphorous acid strong acid?

 

[nehaoscar]

??

 

[nehaoscar]

Mg + 2H2O = Mg(OH)2 + H2

Mg (24.3) + O (16+16) + H (1+1) = 58.3 Mr ... so shouldn't A be wrong?

But then it's D ... is it slightly soluble then?

 

[nehaoscar]

??

 

[Mathemagical]

View attachment 54419
2Mg + 2H2O = 2MgOH + H2

Mg (24.3) + O (16) + H (1) = 41.3 Mr ... so shouldn't A be wrong?

But then it's D ... is it slightly soluble then?

Magnesium burns in steam to produce white magnesium oxide and hydrogen gas.
http://tinyurl.com/nlg5ujc

 

[nehaoscar]

Is it possible to form such an alkene for C? I think it's not because the answer is B ... but could someone tell me why it's not possible?

 

[qwertypoiu]

View attachment 54417
??

C, since CO2 is not polar

 

[Mathemagical]

View attachment 54421
Is it possible to form such an alkene for C? I think it's not because the answer is B ... but could someone tell me why it's not possible?

It is possible. However, you can only form 2 different types since it's symmetrical.

Option B involves 4 different alkenes due to cis-trans isomerism.

 

[qwertypoiu]

The answer is A

I believe that phosphoric acid is a weak acid, so is the phosphorous acid strong acid?

I think Phosphoric acid is formed when P4O10 is put in water. It's considered strong I think, although it's pH is 3.
At least it's not 4-6