Orthoboric Acid

Q.

Why is sulphuric acid not used during the reaction of alcohols with KI?

Q. Assertion (A): Nitration of benzene with nitric acid requires the use of concentrated sulphuric acid.

Reason (R): The mixture of concentrated sulphuric acid and concentrated nitric acid produces the electrophile, $N{0}_2^{+}$

1. Both A and R are correct but R is not the correct explanation of A.
2. Both A and R are not correct.
3. Both A and R are correct and R is the correct explanation of A.
4. A is not correct but R is correct.

Q. A solution containing 0.1 mole of urea in 1 L ofglacial acetic acid, when cooled the first crystalwhich appears at the freezing point contain themolecules of

Q.

Which chemical is known as king of chemicals?

1. ${\mathrm{H}}_2{\mathrm{CO}}_3$

2. $\mathrm{HCl}$

3. ${\mathrm{CH}}_3\mathrm{COOH}$

4. ${\mathrm{H}}_2{\mathrm{SO}}_4$

Q.

What is endpoint in titration?

Q. Boric acid $\left(H_{3}B{O}_3\right)$ has:

1. Layer structure in which $B{O}_3$ units are linked by oxygen
2. Trigonal structure
3. Tetrahedral structure
4. Layer structure in which planar $B{O}_3$ units are linked by hydrogen bonding

Q. pure water boils at 373k and purenitric acid boils at 359k .The azeotropic mixture of water and nitric acidboilsat Tk.

Q. In the nitration of benzene using a mixture of conc. $H_{2}S{O}_4$ and conc. $HN{O}_3$, the species which initiates the reaction is _________.

1. $N{O}_2$
2. $N{O}_2^{-}$
3. $N{O}_2^{+}$
4. $N{O}^{+}$

Q.

Explain what happens when boric acid is heated.

Q.

The compound that is not a lewis acid is

1. ${\mathrm{BCl}}_3$

2. ${\mathrm{BaCl}}_2$

3. ${\mathrm{AlCl}}_3$

4. ${\mathrm{SnCl}}_4$

Q.

Chemical name for ${\mathrm{Na}}_2{\mathrm{PbO}}_2$

Q. Which of the following halides undergo $E_2$ elimination?

1. 
2. 
3. 
4. 

Q. The treatment of alkyl chlorides with aqueous $KOH$ leads to the formation of alcohols but in the presence of alcoholic $KOH$, alkenes are major products. Explain.

Q.

18(a) Boric acid is a tribasic acid.

1. True
2. False

Q. Reaction between diethyl cadmium and acetyl chloride leads to the formation of

1. Dimethyl ketone
2. Diethyl ketone
3. Ethyl methyl ketone
4. Acetaldehyde

Q.

Is boric acid a protic acid? Explain.

Q.

$B(OH{)}_3+NaOH\rightleftharpoons NaB{O}_2+Na[B(OH{)}_4{]}^{-}+H_{2}O$

How can the reaction above be made to proceed in the forward reaction?

1. Addition of cis-1, 2-diol

2. Addition of borax

3. Addition of trans-1, 2-diol

4. Addition of $N{a}_{2}HP{O}_4$

Q. What happens when a methyl orange solution is mixed with $HCl$?

1. The solution turns yellow
2. The solution turns red
3. The solution turns blue
4. The solution turns pink

Q. Formalin is :

1. a dilute sucrose solution
2. a solution of fructose
3. none of the above
4. 40$\%$ aq. solution of formaldehyde

Q.

Name the following:

The process of removal of water from organic compounds.

Q.

Why is Carboxymethyl cellulose added while making detergent powder?

Q.

(a) Classify following oxides as neutral, acidic, basic or amphoteric:

$CO,B_2{O}_3,Si{O}_2,C{O}_2,A{l}_2{O}_3,Pb{O}_2,T{l}_2{O}_3$

(b)Write suitable chemical equations to show their nature.

Q. Which of the following statement (s) about $H_{3}B{O}_3$ is / are correct?

1. It is a strong tribasic acid.
2. It is prepared by acidifying an aqueous solution of borax
3. It has a layer structure in which planar $B{O}_3$ units are joined by hydrogen bonds.
4. It does not act as proton donor as it acts as a lewis acid by accepting lone pair hydroxyl ions.

Q.

Boric acid is polymeric due to
(a) its acidic nature (b) the presence of hydrogen bonds
(c) its monobasic nature (d) its geometry

Q. How will you convert $\text{4-nitrotoluene to 2-bromobenzoic acid?}$

Q. The oxoacid of phosphorous that is easily obtained from a reaction of alkali and white phosphorus and has two $P-H$ bounds, is:

1. Phosphinic acid
2. Hypophosphoric acid
3. Pyrophosphorus acid
4. Phosphonic acid

Q.

Give a reason for the following.

Phosphoric acid is a tribasic acid.

Q. A compound $\left(A\right)$ of boron reacts with $NM{e}_3$ to give an adduct $\left(B\right)$ which on hydrolysis gives a compound $\left(C\right)$ and hydrogen gas. Compound $\left(C\right)$ is an acid. Identify the compounds $A,B$ and $C$. Give the reactions involved.

Q.

Hydrochloric acid is used in the preparation carbon dioxide. Give a balanced equation to prepare carbon di oxide and property of $HCl$ illustrated by the reactions.

Q. According to hard and soft acid base principle, a hard acid:

1. has low charge density
2. shows preference for soft bases
3. shows preference for donor atoms of low electronegativity
4. is not polarizable