Chemistry MCQ thread...

[ideggkr]

Can anyone answer this?

 

[xHazeMx]

The 7 isomers of C3H4Cl2 :

1. CH3CH=CCl2

2 & 3. CH3Cl=CHCl (this has a -cis and a -trans form)

4. CH2ClCCl=CH2

5 & 6. CH2Cl=CHCl (this also has a -cis and a -trans form)

7. CHCl2CH=CH2


I hope that made sense.

check 5 & 6 there is one extra hydrogen atom, thx anyways

Oops, I typed it wrong.
CH2ClCH=CHCl

no problem, that was really helpful

 

[xHazeMx]

Can anyone answer this?

it's B right ?

 

[kakarocks]

Can anyone answer this?

its b

 

[xHazeMx]

answer this giving an explanation for ur answer

 

[Xthegreat]

C

 

[Anonymousx3]

Can anyone answer this?

it's B right ?

Please can you explain why?

 

[Zishi]

answer this giving an explanation for ur answer

C - because whether a reaction will occur spontaneously OR not always depend on its activation energy.

 

[Zishi]

Can anyone answer this?

it's B right ?

Please can you explain why?

Because A and D are soluble things. As for B and C, they're both group 2 metal carbonates. The solubility of metal carbonates decreases down the group, so most probably it has to be B. Plus Mg2+ ions and carbonate ions were already present before addition of calcium hydroxide, and it's asking us what will be formed after its addition, so again it's most probably B.

 

[Anonymousx3]

answer this giving an explanation for ur answer

Yeah, I think it's C too.

Although deltaH is negative and the reaction is thermodynamically favourable, it's not kinetically feasible (activation energy's high and the reaction's very slow). You'd need a lot of energy to break the C-C covalent bonds and restructure the lattice (from tetrahedral to layered structure).

 

[xHazeMx]

Can anyone answer this?

it's B right ?

Please can you explain why?

sorry had to go. anyways zishi answered u

 

[xHazeMx]

answer with an explanation

 

[Zishi]

answer with an explanation

B, because it will give MgO and one mole of CO2. 1 mole of any gas has 24dm^3 volume.

 

[xHazeMx]

answer with an explanation

 

[Zishi]

answer with an explanation

A, by eliminating the other options. The oxidation states of all the atoms remains same.

 

[xHazeMx]

answer with an explanation

A, by eliminating the other options. The oxidation states of all the atoms remains same.

how the oxidation number of Ag remains the same? what will be the oxidation number of the (S2O3)2 part ???

 

[Zishi]

answer with an explanation

A, by eliminating the other options. The oxidation states of all the atoms remains same.

how the oxidation number of Ag remains the same? what will be the oxidation number of the (S2O3)2 part ???

Look, in Na2S2O3, oxidation state of S2O3 is 2-, so in that Ag thing, it's oxidation state will also be -2

Ag + 2(-2) = -3

Ag = +1

So oxidation state of Ag remains same.

 

[xHazeMx]

Brilliant ! thx

 

[xHazeMx]

explanation

 

[Anonymousx3]

explanation

The intermediate is a carbocation. It has a positive charge so it's capable of accepting a lone pair of electrons.
It's an electrophile.