Chemistry MCQ thread...

[histephenson007]

Q Which compound has a boiling point which is influenced by hydrogen bonding ?

A. CH3CHO
B. CH3OCH3
C. HC02H
D HC02CH3

please explan it to me with answer !

C is correct because it is carboxylic acid and Carboxylic acid have hydrogen bonding between them they form dimmer .

But D is a carboxylic acid too! wouldn't the answer be A??

D is an ester

Right, right...sorry my bad

 

[hassam]

which one of the following is involved in determining enthalpy change of reaction
A. no. of stages involved in the reaction
B. Ea or reaction
C. initial and final states of reacting system
D. intermediates in the overall reaction

 

[xHazeMx]

which one of the following is involved in determining enthalpy change of reaction
A. no. of stages involved in the reaction
B. Ea or reaction
C. initial and final states of reacting system
D. intermediates in the overall reaction

A ?

 

[xHazeMx]

how is it D and not B ???? isnt Br an electrophile ???

 

[hassam]

U R WRONG for that enthalpp question...its C...STATEMENT 1....is wrong...try remembering wat was hess's law...nd u ll undrstnd
well i tell u NEva think of electrophillic substitution cos its IN A2...and this paper is of AS

 

[Ash1994]

Ammonium sulfate in nitrogenous fertilisers in the soil can be slowly oxidised by air producing
sulfuric acid, nitric acid and water.
How many moles of oxygen gas are needed to oxidise completely one mole of ammonium
sulfate?
A 1 B 2 C 3 D 4

Explain please!

 

[xHazeMx]

U R WRONG for that enthalpp question...its C...STATEMENT 1....is wrong...try remembering wat was hess's law...nd u ll undrstnd
well i tell u NEva think of electrophillic substitution cos its IN A2...and this paper is of AS

Ops! ya correct. i get it now

 

[xHazeMx]

Ammonium sulfate in nitrogenous fertilisers in the soil can be slowly oxidised by air producing
sulfuric acid, nitric acid and water.
How many moles of oxygen gas are needed to oxidise completely one mole of ammonium
sulfate?
A 1 B 2 C 3 D 4

Explain please!

just make a balanced equation and find out the number of moles of oxygen. here is the balanced equation
(NH4)2SO4 + 4 O2 ------> H2SO4 + 2 HNO3 + 2H2O
so the answer is D

 

[hassam]

Which gas can be most easily liquefied by cooling and applying pressure?

A. Ar

B. H2

C. HF

D. CH4

 

[mizmoody]

Q1 ka answer is C
Q2. ka answer is B

HOWWW???? explain plx

 

[xHazeMx]

Which gas can be most easily liquefied by cooling and applying pressure?

A. Ar

B. H2

C. HF

D. CH4

ops its C, HF has hydrogen bonds so it is most easily liquefied.

 

[Zishi]

Which gas can be most easily liquefied by cooling and applying pressure?

A. Ar

B. H2

C. HF

D. CH4

C

 

[hassam]

YEA RYT...

 

[hassam]

Why is hydrogen iodide a stronger acid than hydrogen chloride?
A A molecule of hydrogen chloride is more polar than a molecule of hydrogen
iodide.
B The enthalpy change of formation of hydrogen iodide is greater than that of
hydrogen chloride.
C The covalent bond in the hydrogen iodide molecule is weaker than that in the
hydrogen chloride molecule.
D The dissociation of hydrogen chloride molecules is suppressed by the stronger
permanent dipole–permanent dipole interactions.

 

[xHazeMx]

Why is hydrogen iodide a stronger acid than hydrogen chloride?
A A molecule of hydrogen chloride is more polar than a molecule of hydrogen
iodide.
B The enthalpy change of formation of hydrogen iodide is greater than that of
hydrogen chloride.
C The covalent bond in the hydrogen iodide molecule is weaker than that in the
hydrogen chloride molecule.
D The dissociation of hydrogen chloride molecules is suppressed by the stronger
permanent dipole–permanent dipole interactions.

C ?

 

[hassam]

A chloroalkane W with molecular formula of C5H11Cl exhibits optical activity. On warming
W with alcoholic NaOH, two alkenes X and Y are formed, X being the major product.
One of the products of the reaction between X and hot acidified potassium
manganate(VII) gives a yellow precipitate with alkaline aqueous iodine. Which of the
following could be W?
A CH3CHClCH2CH2CH3 C CH3CH(CH3)CHClCH3
B CH3CH2CHClCH2CH3 D CH3CCl(CH3)CH2CH3

 

[Zishi]

Which gas can be most easily liquefied by cooling and applying pressure?

A. Ar

B. H2

C. HF

D. CH4

ops its C, HF has hydrogen bonds so it is most easily liquefied.

LOL! Good, you're too quick in editing your posts.

Why is hydrogen iodide a stronger acid than hydrogen chloride?
A A molecule of hydrogen chloride is more polar than a molecule of hydrogen
iodide.
B The enthalpy change of formation of hydrogen iodide is greater than that of
hydrogen chloride.
C The covalent bond in the hydrogen iodide molecule is weaker than that in the
hydrogen chloride molecule.
D The dissociation of hydrogen chloride molecules is suppressed by the stronger
permanent dipole–permanent dipole interactions.

C

 

[mizmoody]

sumbdy answer my questions!!!

 

[xHazeMx]

LOL! Good, you're too quick in editing your posts.

 

[hassam]