The order of first ionization energies of the elements Li, Be, B, Na is :

• Li> Be> B > Na

• Be > B > Li > Na

• Na > Li > B> Be

• Be > Li > B > Na

Calculate the mass loss in the following.

${}_1{}^2\mathrm{H} + {}_1{}^3\mathrm{H} \to {}_2{}^4\mathrm{H} + {}_0{}^1\mathrm{n}$

[Given the masses : ²H = 2.014;³H = 3.016; He = 4.004; n = 1.008 amu]  

• 0.018 amu

• 0.18 amu

• 0.0018 amu

• 1.8 amu

Δ H and ΔS for a reaction are +30.558 kJ mol^-1 and 0.066 kJ K^-1mol^-1 at 1 atm pressure. The temperature at which free energy change is equal to zero and the nature of the reaction below this temperature are :

• 483 K, spontaneous

• 443 K, non-spontaneous

• 443 K, spontaneous

• 463 K, non-spontaneous

An alkene having the molecular formula C₉H₁₈ on ozonolysis gives 2, 2-dimethyl propanal and 2-butanone. The alkene is :

• 2, 2, 2-trimethyl-3-hexene

• 2, 2, 6-trimethyl-3-hexane

• 2, 3, 4-trimethyl-2-hexene

• 2, 2, 4-trimethyl-3-hexene

Observe the following reactions and predict the nature of A and B:

• A and B both are 

• A and B both are 

• A is  and B is 

• A is  and B is 

16.

Nitration of aniline in strongly acidic medium, result in the formation of m-nitroaniline also. This is because :

• amino group is meta orienting during electrophilic substitution reaction

• nitro group goes always to the meta position irrespective of the substituents

• nitration of aniline is a nucleophilic substitution reaction in strongly acidic medium

• in strongly acidic conditions aniline is present as anilinium ion

How many σ and Π bonds are present in toluene?

• 3Π + 8σ

• 3Π + 10σ

• 3Π + 15σ

• 6Π + 3σ

Which of the following Fischer's projection formula is identical to D-glyceraldehyde?

The name of the compound fig is:

• (2Z, 4Z)-2, 4-hexadiene

• (2Z, 4E)-2, 4-hexadiene

• (2E, 4Z)-2, 4-hexadiene

• ( 4E, 4Z)-2, 4-hexadiene

When 32.25 g of ethyl chloride is subjected to dehydrohalogenation reaction the yield of the alkene formed is 50%. The mass of the product formed is (atomic mass of chlorine is 35.5).

• 14 g

• 28 g

• 64.5 g

• 7 g