M.C.Q (1 Marks)

MCQ 11 Mark

The catalyst required for the given reaction is
$
HC=CH+\text { dil. } H_2 SO_4 \xrightarrow{\text { Catalyst }} CH_3 CHO
$

A
Pd
B
$AlCl _3$
C
Pt
✓
$HgSO _4$

Answer

Correct option: D.

$HgSO _4$

(d) $HgSO _4$
Explanation: Alkynes are not readily hydrated due to their low reactivity towards electrophilic addition reactions.Further dilute $H _2 SO _4$ has no effect on carbon carbon triple bond. In the presence of HgSO 4 as catalyst, hydration occurs readily.

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MCQ 21 Mark

The correct equation for the change in enthalpy is:

✓
$\Delta H =\Delta U + p \Delta V$
B
$\Delta H =\Delta U + n \frac{p}{V}$
C
$\Delta H =\Delta U +\frac{p}{V}$
D
$\Delta H=\Delta U+T \Delta V$

Answer

Correct option: A.

$\Delta H =\Delta U + p \Delta V$

(a) $\Delta H=\Delta U+p \Delta V$
Explanation: Enthalpy is a thermodynamic quantity equivalent to the total heat content of a system. It is equal to the internal energy of the system plus the product of pressure and volume.

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MCQ 31 Mark

d-Block Elements are characterized by the:

A
inner d orbitals are not filled.
B
absence of d orbital electrons.
C
filling of outer d orbitals.
✓
filling of inner d orbitals by electrons.

Answer

Correct option: D.

filling of inner d orbitals by electrons.

(d) filling of inner d orbitals by electrons.
Explanation: d-Block elements also known as transition elements are characterized by the filling of inner d orbitals by electrons before the valence-shell s orbital.

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MCQ 41 Mark

Carbon-carbon double bond in alkenes consists of:

A
one strong sigma $(\sigma)$ bond due to head-on overlapping of $sp ^3$ hybridised orbitals one weak pi $(\pi)$ bond.
✓
one strong sigma $(\sigma)$ bond due to head-on overlapping of $sp ^2$ hybridised orbitals one weak pi $(\pi)$ bond.
C
one weak sigma $(\sigma)$ bond due to head-on overlapping of $sp ^2$ hybridised orbitals one weak pi $(\pi)$ bond.
D
one weak sigma $(\sigma)$ bond due to head-on overlapping of $sp ^3$ hybridised orbitals one weak pi $(\pi)$ bond.

Answer

Correct option: B.

one strong sigma $(\sigma)$ bond due to head-on overlapping of $sp ^2$ hybridised orbitals one weak pi $(\pi)$ bond.

(b) one strong sigma $(\sigma)$ bond due to head-on overlapping of $sp ^2$ hybridised orbitals one weak pi $(\pi)$ bond.
Explanation: Sigma bond is formed by the head-on overlap of $sp ^2$ hybridized orbitals while the pi bond is formed by lateral or sideways overlapping of the two 2p-orbitals of the two carbon atoms. Alkenes contain 1 weak pi bond and 1 strong sigma bond.

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MCQ 51 Mark

How many metamers are possible for pentan-1-al?

A
Two
B
Four
C
Three
✓
Zero

Answer

Correct option: D.

Zero

(d) Zero
Explanation:

Here the functional group is aldehyde $(- CHO )$ which is a terminal functional group and hence no metamers are possible.

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MCQ 61 Mark

$Zn ^{2+} / Zn$ represents:

A
the oxidation number of +2 of Zinc
B
the oxidised form of Zinc
✓
redox couple
D
the reduced form of Zinc

Answer

Correct option: C.

redox couple

(c) redox couple
Explanation: This is a redox couple where the following reaction takes place:
$
Zn^{2+}+2 e^{-} \rightarrow Zn
$

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MCQ 71 Mark

Calculate the wavelength (in nanometer) associated with a proton moving at $1.0 \times 10^3 ms^{-1}$ (Mass of proton $=$ $1.67 \times 10^{-27} kg$ and $h =6.63 \times 10^{-34} Js$ )

✓
0.40 nm
B
0.032 nm
C
14.0 nm
D
2.5 nm

Answer

Correct option: A.

0.40 nm

(a) 0.40 nm
$
\begin{aligned}
& \text { Explanation: } \lambda=\frac{h}{m v}=\frac{6.63 \times 10^{-34}}{1.67 \times 10^{-27} \times 1 \times 10^3} \\
& =3.97 \times 10^{-10} m \approx 0.40 nm
\end{aligned}
$

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MCQ 81 Mark

Thermodynamics is not concerned about

A
energy changes involved in a chemical reaction.
✓
the rate at which a reaction proceeds.
C
the feasibility of a chemical reaction.
D
the extent to which a chemical reaction

Answer

Correct option: B.

the rate at which a reaction proceeds.

(b) the rate at which a reaction proceeds.
Explanation: Thermodynamics tells whether a reaction will take place or not. It doesn't tell about the rate (speed) of reaction.

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MCQ 91 Mark

The formula $E = h \nu$ is used to calculate

A
wave number
B
energy of the ejected electrons
C
radiation emitted by a black body
✓
energy of quantum

Answer

Correct option: D.

energy of quantum

(d) energy of quantum
Explanation: Max Planck theorized that energy was transferred in chunks known as quanta, equal to $h \nu$. The variable h is a constant equal to $6.63 \times 10^{-34} J \cdot s$ and the variable $\nu$ represents the frequency in $1 / s$.
This equation allows us to calculate the energy of photons, given their frequency.
If the wavelength is given, the energy can be determined by first using the wave equation $(c=\lambda \times \nu)$ to find the frequency, then using Planck's equation to calculate energy.

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MCQ 101 Mark

The bond dissociation energies of $H _2, Cl _2$ and HCl are 104,58 and $103 kcal mol ^{-1}$ respectively. The enthalpy of formation of HCl would be

A
$+22 kcal mol ^{-1}$
B
$-44 kcal mol ^{-1}$
C
$+44 kcal mol ^{-1}$
✓
$-22 kcal mol ^{-1}$

Answer

Correct option: D.

$-22 kcal mol ^{-1}$

(d) $-22 kcal mol ^{-1}$
Explanation: $-22 kcal mol ^{-1}$

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MCQ 111 Mark

An anion $A ^{3-}$ has 18 electrons. Write the atomic number of A.

A
24
B
21
C
12
✓
15

Answer

Correct option: D.

(d) 15
Explanation: $A ^{3-}$ means it has got an additional 3 electrons. The atomic number is the number of electrons in a neutral atom.
Therefore atomic number $=18-3=15$.

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MCQ 121 Mark

The collective study of separation, identification and quantitative determination of the composition of different substances is dealt under __________ chemistry.

✓
analytical
B
bio
C
inorganic
D
organic

Answer

Correct option: A.

analytical

(a) analytical
Explanation: analytical

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Chemistry M.C.Q (1 Marks)

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