Chemistry: Post your doubts here!

[drowning-in-studies]

The standard enthalpy change for the reaction
2NF3(g) → 2N(g) + 6F(g) is ∆Ho = +1668kJ
What is the bond energy of the N–F bond?
A –556kJ mol–1 B –278kJ mol–1 C +278kJ mol–1 D +556kJ mol–1
Ans is C...but im getting D -_-

 

[Thought blocker]

The standard enthalpy change for the reaction
2NF3(g) → 2N(g) + 6F(g) is ∆Ho = +1668kJ
What is the bond energy of the N–F bond?
A –556kJ mol–1 B –278kJ mol–1 C +278kJ mol–1 D +556kJ mol–1
Ans is C...but im getting D -_-

1668 / (3 * 2)

 

[drowning-in-studies]

1668 / (3 * 2)

Ohh... That's it?
I did the bonds broken-bonds formed

 

[Thought blocker]

Ohh... That's it?
I did the bonds broken-bonds formed

but y?
this was very simple

 

[drowning-in-studies]

but y?
this was very simple

Now its easy

 

[drowning-in-studies]

10.When solid ammonium chloride dissociates at a certain temperature in a 0.500 dm3 container,
ammonia and hydrogen chloride are formed.
NH4Cl (s) NH3(g) + HCl (g)
The initial amount of ammonium chloride was 1.00 mol, and when the system had reached
equilibrium there was 0.300 mol of ammonium chloride.
What is the numerical value of Kc for this reaction under these conditions?
A 0.490 B 1.63 C 1.96 D 3.27
ans is C But how do we get that?

 

[Thought blocker]

10.When solid ammonium chloride dissociates at a certain temperature in a 0.500 dm3 container,
ammonia and hydrogen chloride are formed.
NH4Cl (s) NH3(g) + HCl (g)
The initial amount of ammonium chloride was 1.00 mol, and when the system had reached
equilibrium there was 0.300 mol of ammonium chloride.
What is the numerical value of Kc for this reaction under these conditions?
A 0.490 B 1.63 C 1.96 D 3.27
ans is C But how do we get that?

Makee that initial, change and equilibrium moles table and do it.

 

[drowning-in-studies]

24 Oct-1-ene, CH3(CH2)5CH=CH2, is subjected to thermal cracking.
Which combination of compounds W, X, Y and Z can be obtained?
CH2=CH2 CH3CH=CH2 CH3CH2CH3 CH2=CHCH=CH2
W X Y Z
A W, X, Y and Z
B W, X and Z only
C W, X and Z only
D W and X only
Ans is A But how can there be more carbon atoms after thermal cracking?

 

[Cadence]

Anyone help me to solve this question thx~~~
Total removal of the pollutant So2 is difficult both for economic and technical reasons. the quantities emitted from furnace chimneys can be lowered by using desulfurization plants. The gases are scrubbed with Ca(oH)2 to removes so2. what is the main product formed initially?
9701/11/O/11 ques 18

 

[Thought blocker]

24 Oct-1-ene, CH3(CH2)5CH=CH2, is subjected to thermal cracking.
Which combination of compounds W, X, Y and Z can be obtained?
CH2=CH2 CH3CH=CH2 CH3CH2CH3 CH2=CHCH=CH2
W X Y Z
A W, X, Y and Z
B W, X and Z only
C W, X and Z only
D W and X only
Ans is A But how can there be more carbon atoms after thermal cracking?

Anyone help me to solve this question thx~~~
Total removal of the pollutant So2 is difficult both for economic and technical reasons. the quantities emitted from furnace chimneys can be lowered by using desulfurization plants. The gases are scrubbed with Ca(oH)2 to removes so2. what is the main product formed initially?
9701/11/O/11 ques 18

You guys check out that channel on youtube of metatutor.

 

[Adarsha Shrestha]

Did you get the answer?

 

[Adarsha Shrestha]

2 Equations involving four enthalpy changes are shown.

Na(g) → Na+(g) + e– Na(g) → Na2+(g) + 2e– Na(s) → Na(g)
Na(s) → Na2+(g) + 2e–

∆H= W ∆H = X ∆H = Y ∆H = Z

What is the second ionisation energy of sodium?A 2W B X – W C Y – W D Z – Y
help(

did you get the answer?

 

[Cadence]

did you get the answer?

The Ans is B

 

[Cadence]

Which halogenoalkane produces the highest percentage of product by an SN1 mechanism, when treated with Naoh (aq)
A 2-bromopropane
B 2-chloroprapane
C 1-iodo-2-methylpropane
D 2-iodo-2methylpropane

 

[Thought blocker]

Which halogenoalkane produces the highest percentage of product by an SN1 mechanism, when treated with Naoh (aq)
A 2-bromopropane
B 2-chloroprapane
C 1-iodo-2-methylpropane
D 2-iodo-2methylpropane

which year?

 

[Cadence]

which year?

9701/13/o/13

 

[Thought blocker]

9701/13/o/13

 

[Cadence]

Thank you!!

 

[Cadence]

Anyone pls explain 9701/11/m/14 ques 8 and 9

 

[Thought blocker]

Anyone pls explain 9701/11/m/14 ques 8 and 9

did u searched it on that channel?