Chemistry MCQ thread...

[Zishi]

how about the substitution part ( 6.2/1.089 x 10^9 ) ???

It's because we'd kc in terms of Co and to change it in terms of CO2, we'd to do that...

 

[xHazeMx]

D is correct .. how did u get it ?

 

[histephenson007]

HI ----> H + I

Initial pressures: b, 0 , 0
Change in pressures: x , x/2 , x/2
Pressure at equilibrium: (b-x), x/2, x/2

So, Kp= [(x/2)(x/2)] / (b-x)^2

u can solve it to get D

 

[xHazeMx]

HI ----> H + I

Initial pressures: b, 0 , 0
Change in pressures: x , x/2 , x/2
Pressure at equilibrium: (b-x), x/2, x/2

So, Kp= [(x/2)(x/2)] / (b-x)^2

u can solve it to get D

thanks ! i thought change in pressure was x only .. got it now :Yahoo!:

 

[histephenson007]

My question :

Which reagent when mixed and heated with ammonium sulphate, liberates ammonia?

A. Aqueous bromine
B. dilute hydrochloric acid
C. limewater
D. acidified potassium dichromate (IV)

plz..explain

 

[Zishi]

My question :

Which reagent when mixed and heated with ammonium sulphate, liberates ammonia?

A. Aqueous bromine
B. dilute hydrochloric acid
C. limewater
D. acidified potassium dichromate (IV)

plz..explain

Lime water. You've to learn that ammonium salts reacts with bases to given off ammonia.

 

[xHazeMx]

My question :

Which reagent when mixed and heated with ammonium sulphate, liberates ammonia?

A. Aqueous bromine
B. dilute hydrochloric acid
C. limewater
D. acidified potassium dichromate (IV)

plz..explain

Lime water. You've to learn that ammonium salts reacts with bases to given off ammonia.

(NH4)2SO4 + Ca(OH)2 ------> CaSO4 + 2NH3 + 2H2O

 

[Zishi]

People, bring on more tough questions. . .

 

[xHazeMx]

answer this
explain ur choice

 

[farrukh]

Q.. Bromine extracted from dead sea is transported as 52% solution by mass of calcium bromide.. What mass of bromine is carried in 100 tonnes of solution??

A. 80 tonnes
B. 10 tonnes
C. 41.6 tonnes
D. 52 tonnes

 

[Zishi]

answer this
explain ur choice

I'd say that only 2 and 3 are correct. One is incorrect, because HI IS displaced by conc. sulfuric acid. This leaves you with answer C only. But 2 is correct, because iodide ions are oxidised by conc H2SO4 because it is an oxidising agent. Plus HI is a strong reducing agent, so it reduces conc H2SO4 to sulfur products like H2S, SO2, S.

 

[xHazeMx]

Q.. Bromine extracted from dead sea is transported as 52% solution by mass of calcium bromide.. What mass of bromine is carried in 100 tonnes of solution??

A. 80 tonnes
B. 10 tonnes
C. 41.6 tonnes
D. 52 tonnes

A?

 

[farrukh]

no

 

[Zishi]

Q.. Bromine extracted from dead sea is transported as 52% solution by mass of calcium bromide.. What mass of bromine is carried in 100 tonnes of solution??

A. 80 tonnes
B. 10 tonnes
C. 41.6 tonnes
D. 52 tonnes

I get C as the answer. But I believe that it is wrong. . .If I'm right then I'll explain it...

 

[farrukh]

Q.. Bromine extracted from dead sea is transported as 52% solution by mass of calcium bromide.. What mass of bromine is carried in 100 tonnes of solution??

A. 80 tonnes
B. 10 tonnes
C. 41.6 tonnes
D. 52 tonnes

I get C as the answer. But I believe that it is wrong. . .If I'm right then I'll explain it...

You r correct... please post the solution

 

[Zishi]

Q.. Bromine extracted from dead sea is transported as 52% solution by mass of calcium bromide.. What mass of bromine is carried in 100 tonnes of solution??

A. 80 tonnes
B. 10 tonnes
C. 41.6 tonnes
D. 52 tonnes

I get C as the answer. But I believe that it is wrong. . .If I'm right then I'll explain it...

You r correct...explanation please post the solution

Ok so, Mr of CaBr2 = 200

Mass of bromine in it = 160

Mass of bromine in 100 tonnes of solution = (160/200) times 100 times 52%

 

[xHazeMx]

i got it from the second attempt too

 

[Zishi]

i got it from the second attempt too

Hmm, good. More questions, please.

 

[xHazeMx]

alright, everyone, be ready for THE MIGHTY QUESTION

 

[farrukh]

i have more...but i cant post them...i dont have a scanner