Factors Affecting Hydrogen Bonding

Q.

Assertion (A): $\mathrm{HF}$ has a greater boiling point than ${\mathrm{H}}_2\mathrm{O}$.

Reason (R): $\mathrm{HF}$ has a stronger hydrogen bonding than ${\mathrm{H}}_2\mathrm{O}$.

1. Both A and R are true and R is the correct explanation of A.

2. Both A and R are true but R is not the correct explanation for A.

3. A is true and R is false.

4. A is false and R is true.

Q.

The bond lengths of C-X bond in alkyl halide increases in the order:

1. C-F < C-Cl < C-Br < C-I

2. C-F > C-Cl > C-Br = C-I

3. C-F < C-Cl < C-Br = C-I

4. C-F > C-Cl > C-Br > C-I

Q.

Hydrogen bonding is maximum in

1. Ethanol

2. Diethyl ether

3. Ethyl chloride

4. Triethylamine

Q. The order of strength of hydrogen bond is:

1. $N-H\cdots N>O-H\cdots O>F-H\cdots F$
2. $N-H\cdots N>O-H\cdots O>F-H\cdots F$
3. $O-H\cdots O>N-H\cdots N>F-H\cdots F$
4. $F-H\cdots F>O-H\cdots O>N-H\cdots N$

Q.

Carboxylic acids are more acidic than phenol and alcohols because of -

1. Intermolecular hydrogen bonding

2. Formation of dimer

3. Highly acidic hydrogen

4. Resonance stabilization of their conjugate base.

Q. ntWhat is the molality of c2h5oh in water solution which will freeze at -10 degree celcius ?molecular weight of c2h5oh =46, kf of water=1.86n

Q. What is hydrogen bonding and what are the factors affecting it

Q.

Why does $N{H}_3$ form hydrogen bond but $P{H}_3$ does not?

Q.

Xe forms compound with only F and O why?

Q. Why is ether not forming hydrogen bonds?

Q. Covalent compounds have low melting points because:

1. Covalent molecules have definite shape
2. Covalent bond is weaker than ionic bond
3. Covalent bond is less exothermic
4. Covalent molecules are held by weak Van der Waals forces

Q. Why 3d3 configuration is more stable than 3d5 configuration in aqueous medium?

Q. Why does $N{H}_3$ form hydrogen bond but $P{H}_3$ does not?

Q.

Differentiate between ionic and covalent bonding on the basis of the following parameters:

(a) formation
(b) physical state
(c) melting and boiling points
(d) solubility
(e) electrical conductivity

Q.

How many $\mathrm{P}-\mathrm{S}$ and bonds are present in ${\mathrm{P}}_4{\mathrm{S}}_3$?

Q. Which of the following is alicyclic compound?

1. 
2. 
   
3. 
4. 

Q.

Is a triple bond longer than a single bond?

Q. Triple bond is not present in

1. Cyanogen
2. Propene
3. Nitrous Oxide
4. Nitrogen-dioxide

Q.

____ compounds have low melting points and boiling points.

Q.

Suggest the most important type of intermolecular attractive interaction in the following pairs.

(i) n-hexane and n-octane

(ii) I₂ and CCl₄

(iii) NaClO₄ and water

(iv) methanol and acetone

(v) acetonitrile (CH₃CN) and acetone (C₃H₆O).

Q.

The bond angle of Cl₂O is:

1. Smaller than that of H₂O

2. Greater than that of H₂O

3. Smaller than that of F₂O

4. Same as that of F₂O

Q. $K{a}_2$ of Maleic acid is lesser than $K{a}_2$ of fumaric acid due to:

1. Intramolecular hydrogen bonding in the ion formed after one proton removal in fumaric acid
2. Intramolecular hydrogen bonding in the ion formed after one proton removal in maleic acid
3. Intermolecular hydrogen bonding in the ion formed after one proton removal in maleic acid
4. Intermolecular hydrogen bonding in the ion formed after one proton removal in fumaric acid

Q.

Which of the following has highest boiling point?

1. $H_{2}O$
2. $C{H}_4$
3. $N{H}_3$
4. $HF$

Q. The strongest hydrogen bond is formed between _____________ and hydrogen.

1. oxygen
2. fluorine
3. chlorine
4. nitrogen

Q. The order of strength of hydrogen bond is:

1. $N-H\cdots N>O-H\cdots O>F-H\cdots F$
2. $N-H\cdots N>O-H\cdots O>F-H\cdots F$
3. $O-H\cdots O>N-H\cdots N>F-H\cdots F$
4. $F-H\cdots F>O-H\cdots O>N-H\cdots N$

Q. Hydrogen bonds are formed in many compound e.g $H_{2}O$, $HF$ , $N{H}_{3}O$. The bonding point of such compounds depends to large extent on the strength of hydrogen bond of the number of hydrogen bonds. The correct decreasing order of the boiling point of above compound is:

1. $HF>H_{2}O>N{H}_3$
2. $H_{2}O>HF>N{H}_3$
3. $N{H}_3>HF>H_{2}O$
4. $N{H}_3>H_{2}O>HF$

Q.

Differentiate between polar and non-polar covalent compounds.

Q. Hydrogen bonds are formed in many compounds e.g., $H_{2}O,HFandN{H}_3$. The boiling point of such compounds depends to a large extent on the strength of the hydrogen bond and the number of hydrogen bonds. The correct decreasing order of the boiling points of the above compounds is :

1. $HF>H_{2}O>N{H}_3$
2. $H_{2}O>HF>N{H}_3$
3. $N{H}_3>HF>H_{2}O$
4. $N{H}_3>H_{2}O>HF$

Q. Covalent compounds have low melting point because –

1. Covalent molecules have definite shape
2. Covalent bond is weaker than ionic bond
3. Covalent molecules are held by weak Vander Waal’s forces
4. Covalent bond is less exothermic

Q. Arrange the following in the decreasing order of hydrogen bonding :

1. $C{H}_3-OH$ , >$C{H}_3-N{H}_2$ >$C{H}_3-F$ >$C{H}_4$
2. $C{H}_3-OH$>$C{H}_3-F$>$C{H}_3-N{H}_2$ >$C{H}_4$
3. $C{H}_3-F$>$C{H}_3-OH$>$C{H}_3-N{H}_2$>$C{H}_4$
4. $C{H}_4$>$C{H}_3-F$> $C{H}_3-N{H}_2$ >$C{H}_3-OH$