Anomalous Behaviour of Fluorine

Q. Assertion: The boiling point order of group $15$ hydrides is $P{H}_3<As{H}_3<N{H}_3<Sb{H}_3<Bi{H}_3$.
Reason: $H$-bonding in $N{H}_3$ dominates van der Waals forces in bigger $Sb$ molecules.

1. Both Assertion and reason are correct and Reason is the correct explanation for the Assertion
2. Both Assertion and reason are correct and Reason is NOT the correct explanation for the Assertion
3. Assertion is correct and reason is incorrect
4. Assertion is incorrect and reason is correct

Q. The variation of the boiling points of the hydrogen halides is in the order $HF>HI>HBr>HCl$
What explains the higher boiling point of hydrogen fluoride?

1. There is strong hydrogen bonding between HF molecules.
2. The bond energy of HF molecules is greater than in other hydrogen halides.
3. The effect of nuclear shielding is much reduced in fluorine which polarises the HF molecule.
4. The electronegativity of fluorine is much higher than for other elements in the group.

Q.

The melting points and solubility in water of amino acids are generally higher than that of the corresponding halo acids. Explain.

Q. Which of the following halides easily undergoes hydrolysis?

1. $AgCl$
2. $N{F}_3$
3. $Si{F}_4$
4. $C{F}_4$

Q.

Which acid of each pair shown here would you expect to be stronger?

(i) CH₃CO₂H or CH₂FCO₂H

(ii)CH₂FCO₂H or CH₂ClCO₂H

(iii) CH₂FCH₂CH₂CO₂H or CH₃CHFCH₂CO₂H

(iv)

Q.

Write the importance of synthetic polymer in our life.

Q. Why tricyclopropyl carbocation is more stable than triphenylcarbocation. Triphenylcarbocation should be more stable since it has resonance instead of tricyclopropyl carbocation

Q.

Give Reason :

Hydrogen fluoride $\left(\mathrm{HF}\right)$ is the least volatile and hydrochloric acid $\left(\mathrm{HCl}\right)$ is the most volatile among hydrogen halides.

Q.

Arrange the following compounds in increasing order of their property as indicated:

(i) Acetaldehyde, Acetone, Di-tert-butyl ketone, Methyl tert-butyl ketone (reactivity towards HCN)

(ii) CH₃CH₂CH(Br)COOH, CH₃CH(Br)CH₂COOH, (CH₃)₂CHCOOH, CH₃CH₂CH₂COOH (acid strength)

(iii) Benzoic acid, 4-Nitrobenzoic acid, 3, 4-Dinitrobenzoic acid, 4-Methoxybenzoic acid (acid strength)

Q. Why are pentahalides more covalent than trihalides ?

Q.

Name the compound which is insoluble in cold water but soluble in hot water?

Q. Fluorine does not have d-orbitals in its valence shell - True or False?

1. True
2. False

Q. Which of the following statement is not correct for nitrogen?
[1 Mark]

1. It electronegativity is very high
2. d-orbitals are available for bonding
3. It is a typical non-metal
4. Its molecular size is small

Q. Which of the following statement is not true for halogens ? 1) All form monobasic oxyacids. 2) All are oxidizing agents. 3) All but fluorine show positive oxidation states. 4) Chlorine has the highest electron gain enthalpy.

Q.

How do Group $7$ elements react?

Q. Comparatively high boiling point of $HF$ is due to:

1. High reactivity of fluorine
2. Small size of hydrogen atom
3. Formation of hydrogen bonds and consequent association
4. High I.E. of flourine

Q. For carbanion stability order will be :

1. $P>R>Q>S$
2. $Q>R>S>R$
3. $P>Q>S>R$
4. $S>R>Q>P$

Q.

Assertion: Atom is the smallest portion of matter which can take part in chemical combination.

Reason: Atoms of all elements can exist independently.

1. both assertion and reason are correct and the reason is the correct explanation for the assertion

2. both assertion and reason are correct but the reason is not the correct explanation for assertion.

3. the assertion is correct but reason is incorrect

4. the assertion is incorrect but the reason is correct

Q.

phenol is an acid but it does not react with sodium bicarbonate soln.why?

Q.

Fajan rule in nacl and cucl I didn't understand even after seeing the video...

Q.

Choose the correct statements:

1. Fluorine is a super halogen

2. Iodine shows Lewis basic character

3. $AgF$ is insoluble in water

4. $SC{N}^{-}$ is a pseudohalide

Q.

Do Halogens React With Water?

Q. Which of the following cannot be hydrolysed?

1. $O{F}_2$
2. $SiC{l}_4$
3. $NC{l}_3$
4. $S{F}_4$

Q. Which of the following is most electronegative element?

1. Li
2. Al
3. C
   
4. F
5. Ca

Q.

Assertion (A): Ammonia has hydrogen bonding whereas $\mathrm{HCl}$ has no hydrogen bonding.

Reason (R): Nitrogen has greater electronegativity than chlorine.

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 of A.

3. A is true and R is false.

4. A is false and R is true.

Q. Explain why is ortho nitrophenol more acidic than ortho methoxyphenol?

Q. Stability decreases in the order

1. H-F > H-Cl > H-Br > H-I
2. H-Cl > H-F > H-Br > H-I
3. H-F > H-Br > H-Cl > H-I
4. H-F > H-Cl > H-I > H-Br

Q. What is the contribution of chemistry in the following fields?
a) Industry
b) Clothings
c) Cosmetics
d)National Defence
e) Medicines

Q.

Phenol is more acidic than alcohol. Give reasons.

Q. Fluorine does not show variable oxidation states because_________

1. of absence of d-orbitals
2. absence of p-orbitals
3. absence of s-orbital
4. it is a halogen