GATE Overflow for GATE XE - Recent questions and answers in Chemistry of High Polymers

GATE XE 2026 | Question: 110

Tue, 24 Feb 2026 15:35:19 +0000

Resol is produced by reaction of $\_\_\_\_\_\_$.

phenol with an excess of formaldehyde in presence of a base catalyst
formaldehyde with an excess of phenol in presence of a base catalyst
phenol with an excess of formaldehyde in presence of an acid catalyst
an equimolar mixture of phenol and formaldehyde at neutral $\text{pH}$

GATE XE 2026 | Question: 117

Tue, 24 Feb 2026 15:33:00 +0000

A certain amount of plasticizer with a glass transition temperature $\left(T_{g}\right)$ of $-50^{\circ} \mathrm{C}$ was added to a polymer to reduce its $T_{g}$ from $70^{\circ} \mathrm{C}$ to $30^{\circ} \mathrm{C}$. Using the Fox equation, the weight fraction of the plasticizer used is $\_\_\_\_\_\_$ (rounded off to two decimal places).

GATE XE 2026 | Question: 132

Tue, 24 Feb 2026 15:29:19 +0000

Match the vitamins in Column I with their respective coenzyme forms listed in Column II.

$$\begin{array}{|ll|ll|} \hline & \textbf{Column I} & & \textbf{Column II} \\ \hline \text{P.} & \text{Vitamin } B_{1} & 1.& \text{Tetrahydrofolate} \\ \hline Q. & \text{Vitamin } B_{2} & 2.& \text{Methylcobalamin} \\
\hline R. & \text{Pantothenic acid} & 3. & \text{Thiamine pyrophosphate} \\ \hline S. & \text{Vitamin } B_{12} & 4. &\text{Flavin adenine dinucleotide} \\ \hline T. & \text{Folic acid} & 5.& \text{Coenzyme A} \\ \hline
\end{array}$$

$\text{P-3; Q-4; R-5; S-2; T-1}$
$\text{P-4; Q-3; R-1; S-5; T-2}$
$\text{P-1; Q-5; R-4; S-2; T-3}$
$\text{P-5; Q-2; R-4; S-3; T-1}$

GATE XE 2025 | Question: 120

Sun, 04 May 2025 19:05:00 +0000

The 'unperturbed dimension' of the polymer chain is represented as,

$$\left(\overline{r_{o}^{2}}\right)^{1 / 2} \propto \bar{l}(n)^{1 / 2}$$

where,
$\left(\overline{r_{o}^{2}}\right)^{1 / 2}=$ root-mean square end-to-end distance\

$\bar{l}=$ average length of a segment

$n=$ number of segments in the chain

Using the above information, root-mean square end-to-end distance of a branched polyethylene would be $\_\_\_\_\_\_\_\_$ when compared with that of the linear polyethylene of the same molecular weight and the same number of segments.

Same
Higher
Lower
Exactly $\sqrt{2}$ times

GATE XE 2024 | Question: 48

Sun, 21 Jul 2024 16:42:08 +0000

Which of the following options is/are true for glass transition temperature $\mathrm{T}_{\mathrm{g}}$ ?

Above $\mathrm{T}_{\mathrm{g}}$, glass transforms from an amorphous solid to a viscous liquid.
$\mathrm{At}_{\mathrm{g}}$, glass transforms from an amorphous solid to a crystalline solid.
$\mathrm{T}_{g}$ is dependent on the heating rate.
Below $\mathrm{T}_{\mathrm{g}}$, nucleation and growth takes place in glass.

GATE XE 2024 | Question: 101

Sun, 21 Jul 2024 16:41:21 +0000

Melting phenomenon in a semi-crystalline polymer is a __________ order phase transition.

zeroth
first
second
third

GATE XE 2023 | Question: 54

Wed, 14 Feb 2024 18:09:31 +0000

Q. 64
An electrochemical cell consists of pure $\mathrm{Zn}$ electrode (anode) and a hydrogen electrode (cathode) in a dilute $\mathrm{Zn}^{+2}$ solution. The overall reaction is:
\[
\mathrm{Zn}(\mathrm{s})+2 \mathrm{H}^{+}=\mathrm{H}_{2}+\mathrm{Zn}^{+2}
\]

If the overall cell potential is $+0.690 \mathrm{~V}$, then the value of $\ln \frac{\left[\mathrm{Zn}{ }^{+2}\right]}{\left[\mathrm{H}^{+}\right]^{2}}$ is (rounded off to two decimal places)

Given: Pressure of hydrogen gas $=1 \mathrm{~atm} ;$ Temperature $=298 \mathrm{~K}$;
$\frac{R T}{F}=0.0256 \mathrm{~V}$, where $\mathrm{R}$ is gas constant and $\mathrm{F}$ is Faraday constant
The standard reduction potential of:
$\mathrm{Zn}^{+2}+2 \mathrm{e}=\mathrm{Zn}\left(\mathrm{E}^{\mathrm{o}}=-0.762 \mathrm{~V}\right)$ versus Standard Hydrogen Electrode
\[
2 \mathrm{H}^{+}+2 \mathrm{e}=\mathrm{H}_{2}\left(\mathrm{E}^{o}=0 \mathrm{~V}\right)
\]

GATE XE 2023 | Question: 115

Wed, 14 Feb 2024 18:08:29 +0000

\begin{tabular}{l|l}
Q.125 & \begin{tabular}{l}
Among the options given, which method(s) is/are used for the synthesis of atactic \\
polystyrene?
\end{tabular} \\
\hline

& Free radical polymerization \\
\hline
& Ring opening polymerization \\
\hline
& Polycondensation \\
& Ionic polymerization
\end{tabular}