chanllenging mcqs

[hunter94]

chanllenging mcqs for chem ....plz ask difficult ones

 

[hassam]

BH3 reacts with (CH3)3N to give (CH3)3NBH3. Which one of the following will be true of
(CH3)3NBH3?
A It is optically active.
B It contains hydrogen bonding.
C The B atom is electron deficient.
D The B atom is tetrahedrally coordinated.

 

[hassam]

Magnesium reacts readily with dilute hydrochloric acid to form magnesium chloride and
hydrogen.
Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g)
The standard enthalpy change for this reaction can be measured in the laboratory.
What further information is needed in order to calculate the standard enthalpy change of
formation of magnesium chloride?
1 ΔHf
, for HCl(aq)
2 ΔHf
, for H2(g)
3 first and second ionisation energies of Mg

 

[intel1993]

hey hassam from where u r actually preparing...??
i mean this question r really gud..................
can u tell me d source??

 

[sweetiepie]

r these important ones????

 

[ideggkr]

BH3 reacts with (CH3)3N to give (CH3)3NBH3. Which one of the following will be true of
(CH3)3NBH3?
A It is optically active.
B It contains hydrogen bonding.
C The B atom is electron deficient.
D The B atom is tetrahedrally coordinated.

D?

 

[ideggkr]

Magnesium reacts readily with dilute hydrochloric acid to form magnesium chloride and
hydrogen.
Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g)
The standard enthalpy change for this reaction can be measured in the laboratory.
What further information is needed in order to calculate the standard enthalpy change of
formation of magnesium chloride?
1 ΔHf
, for HCl(aq)
2 ΔHf
, for H2(g)
3 first and second ionisation energies of Mg

1 only?

 

[ideggkr]

Btw I'm not 100% sure.

Plz explain to me if i'm wrong

 

[kshumaila52]

BH3 reacts with (CH3)3N to give (CH3)3NBH3. Which one of the following will be true of
(CH3)3NBH3?
A It is optically active.
B It contains hydrogen bonding.
C The B atom is electron deficient.
D The B atom is tetrahedrally coordinated.

d is correct, before bond formaion it as electron deficient due to 6 electrons around it but after compoud fornd, it become tetrahedral

 

[kshumaila52]

Magnesium reacts readily with dilute hydrochloric acid to form magnesium chloride and
hydrogen.
Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g)
The standard enthalpy change for this reaction can be measured in the laboratory.
What further information is needed in order to calculate the standard enthalpy change of
formation of magnesium chloride?
1 ΔHf
, for HCl(aq)
2 ΔHf
, for H2(g)
3 first and second ionisation energies of Mg

only 1 s correct

 

[Hateexams93]

why ? i think its B(1 and 2)

 

[prats]

every mscq is challenging in chemistry for me....m zero in chemmm

 

[hassam]

u pp; r ryt.....itS D and 1 only

 

[hassam]

 

[hassam]

just stik with the ICE table

 

[ideggkr]

0.313. C

 

[hassam]

no....i guess u used moles and not the conc...its AA by the way

 

[ideggkr]

no....i guess u used moles and not the conc...its AA by the way

Oh! I get it.

I never used mole instead of conc before.. must beware
thanks :fool:

 

[intel1993]

hey hassam/ideggkr can u plzz show the steps............???

 

[intel1993]

hey can any one plz tell that the abv mcq is from which paper???