Solution

The number of σ and π bonds in CH₂= CH – CH = CH₂

8σ and 2π bonds
9σ and 1π bonds
9σ and 3π bonds
9σ and 2π bonds

Solution

As shown above, the given compound (1, 3-butadiene)contains 9σ and 2π bonds

In a closed system : A_(s) ⇌ 2B_(g) + 3C_(g), if the partial pressure of C is doubled, then partial pressure of B will be:

two times the original value
one-half of its original value
\(\frac{1}{2\sqrt{2}}\) times the original value
\(2\sqrt{2}\) times its original value

Solution

What is the correct orbital designation of an electron with the quantum number, n = 4, l = 3, m = –2, s = 1/2 ?

Solution

n = 4 represents 4th orbit

l = 3 represents f subshell

m = –2 represents orientation of f-orbital

s = 1/2 represents direction of spin of electron.

∴ The orbital is 4f.

A weak acid, HA is found to be 10% ionized in 0.01 M aqueous solution.Calculate the pH of a solution which is 0.1 M in HA and 0.05 M in Na A.

5.365
6.355
3.653
6.593

Solution

α= 0.1,
\(K_{a}=\frac{\alpha ^{2}C}{1-\alpha }=\frac{(0.1)^{2}\times (0.01)}{(1-0.1)}= 1.11\times 10^{-4}\)

Now pK_a= –log 1.11×10^-4=3.9542

\(pH=pK_{a}+log\frac{[salt]}{[acid]}\)

= 3.9542 +log\(\left [ \frac{0.05}{0.10} \right ]= 3.653\)

Phenol is heated with a solution of mixture of KBr and KBrO₃.The major product obtained in the above reaction is :

2-Bromophenol
3-Bromophenol
4-Bromophenol
2, 4, 6-Tribromophenol

Solution

Solution

274.339 K
– 1.339 K
257.3K
– 1.339°C

Solution

Which of the following chemicals is not present in clear hard water?

MgCO₃
MgSO₄
Mg(HCO₃)₂
CaCl₂

Solution

MgCO₃ is insoluble in water.

Which is the correct order of electronegativity?

F > N < O > C
F > N > O > C
F> N > O < C
F < N < O =C

DIRECTIONS : These are Assertion-Reason type question. Question contain two statements:Statement-1 (Assertion) and Statement-2 (Reason). Answer these question from the following four options.

Statement-1 :CN^– ion is an ambident nucleophile.
Statement-2 :Nucleophiles are electron rich species.

Statement-1 is true, Statement-2 is true, Statement-2 is a correct explanation for Statement -1
Statement -1 is true, Statement-2 is true ; Statement-2 is NOT a correct explanation for Statement - 1
Statement - 1 is true, Statement-2 is false
Statement -1 is false, Statement-2 is true

Solution

If Z is the number of atoms in the unit cell that represents the closest packing sequence ….. ABC ABC ……, the number of tetrahedral voids in the unit cell is equal to :

Solution

In cubic closed pack system (CCP system) .......ABC
ABC....... type of arrangement of layers is found. In this system, there are atoms at the corners as well as centre of the unit cell
∴ No. of atoms per unit cell = 8 × \(\frac{1}{8}\) + 1 = 2
Hence, the no. of tetrahedral voids in a unit cell = 2Z