Chemistry: Post your doubts here!

[mygjjk]

In order for atoms to be in the same plane the bond angle must be 120 degrees
The central carbon atom in 1 and 2 has 3 B.P so the bond angle is 120 while in 3 the central carbon will also make a bond with hydrogen so it will have 4 B.P hence the bond angle will be 109.5 not 120.

sorry if this is a dumb question but what do u mean by B.P?

 

[iman iqbal]

sorry if this is a dumb question but what do u mean by B.P?

bond pair

 

[iman iqbal]

You'll have to make a Hess cycle for this question.
View attachment 64781

when drawing the hess cycle, do we always put the elements at the bottom?

 

[Shemyaa]

when drawing the hess cycle, do we always put the elements at the bottom?

Its really based on what you're dealing with, like what kind of reaction do you have and the kind of enthalpy you're trying to find.

 

[Shemyaa]

Idk why I have a feeling they'll get something annoying in redox reactions

 

[iman iqbal]

please help with this

 

[Kanekii]

please help with thisView attachment 64782

B, As Ionic compounds conduct electricity in liquid state. Only 1 and 2 can be ionic compounds. As Y loses an electron to obtain stable electronic configuration and Both X and Z gain electron/s achieve stable electronic configuration.

 

[danidanidani]

Which compound shows optical isomerism?

A.) 2-chloropropane B.)1,2-dichloropropane C.) 1,3-dichloropropane D.) 2,2-dicholoropropane

 

[Kanekii]

Which compound shows optical isomerism?

A.) 2-chloropropane B.)1,2-dichloropropane C.) 1,3-dichloropropane D.) 2,2-dicholoropropane

Its B, As it has 4 different groups attached to the carbon atom.
CH3-CH(Cl)-CH2Cl

 

[silverr1004]

Can someone please explain this question to me
The answer is D

 

[blymphocytes]

Can someone please explain this question to me
The answer is D
View attachment 64784

Even i had the same question!
And a few others

How do you calculate for such questions? The answer is B


The anser is D.........but i dont get why 2 is wrong

 

[blymphocytes]

Idk how to arrive at an answer......the answer is A

 

[iman iqbal]

View attachment 64787Idk how to arrive at an answer......the answer is A

P1V1=P2V2
(5*12)+(6*10)=P2*(5+10)
p2= 8

 

[blymphocytes]

P1V1=P2V2
(5*12)+(6*10)=P2*(5+10)
p2= 8

Thanks!!

 

[blymphocytes]

Who did qp 11 and how did you find it?

 

[Maiday Holsey]

Who did qp 11 and how did you find it?

I did it and it was hard af. What about you?

 

[blymphocytes]

I did it and it was hard af. What about you?

Sameee......i'm not even confident about my answers

 

[blymphocytes]

Most of them from 1 to 20 were C and 21-40 were A :O

I did it and it was hard af. What about you?

 

[Shemyaa]

Sameee......i'm not even confident about my answers

I did 12, and it was horrible as well.
The questions needed alot of time, and most questions were organic.
If we had more time I'd say it was good.
I had no time to check I just answered.

 

[wonghuiyin]

Q: Equal masses of barium carbonate and magnesium carbonate powders are mixed together. The mixture is then heated using a Bunsen burner flame until there is no further change. A gas is given off. Which statements are correct?
1) The residue left after heating reacts with aqueous hydrochloric acid to produce carbon dioxide.
2) The percentage decrease in mass after heating is 26% (to 2 significant figures).
3) The gas given off during heating relights a glowing splint.

1. The fact that some carbon dioxde is produced when the residue is treated with acid means that there is a carbonate present.

2. If 50% of the mixture is magnesium carbonate (relative mass = 84) and it decomposes to MgO (relative mass 40), then the 50% loses 44/84 x 100 % of its mass = 52.4%
so the mass loss of the 100% mixture = 26.2%( dont get this part)

How from 52.4 become 26.2?