List of top Chemistry Questions

a, b, c, d are electromagnetic radiations. Frequencies of a, b, c are $3 \times 10^{15$ Hz, respectively, whereas the wavelength of c, d are 400 nm, 750 nm, respectively. The increasing order of their energies is}

The standard reduction potentials are: $ E^\circ_{\text{Ag}^+/\text{Ag}} = +0.80\, \text{V} $ and $ E^\circ_{\text{Cu}^{2+}/\text{Cu}} = +0.34\, \text{V} $. What will happen when a copper rod is placed in a solution of silver nitrate?

Consider the following:
Statement-I: Both BeSO$_4$ and MgSO$_4$ are readily soluble in water.
Statement-II: Among the nitrates of alkaline earth metals, only Be(NO$_3$)$_2$ on strong heating gives its oxide, NO$_2$, and O$_2$.
The correct answer is

Consider the following
Statement-I: Kolbe's electrolysis of sodium propionate gives n-hexane as product.
Statement-II: In Kolbe's process, CO$_2$ is liberated at anode and H$_2$ is liberated at cathode.

Observe the following given changes: \[ \text{wood} \xrightarrow[\text{absence of air}]{\text{high temperature}} X
\text{coal} \xrightarrow[\text{absence of air}]{\text{high temperature}} Y \] X and Y respectively are:

In each of four separate beakers (I, II, III, IV), X mL of 1M Fe$_2$O$_3$·xH$_2$O colloidal solution is present.
Equal volume and equal concentration of KCl, K$_4$[Fe(CN)$_6$], K$_3$PO$_4$ and K$_2$SO$_4$ was added into I, II, III and IV respectively.
The efficiency of precipitations in these beakers follows the order

Match the following polymers with their applications:

Consider the following Statement-I : Lactose is composed of $ \alpha $-D-glucose and $ \beta $-D-glucose. Statement-II : Lactose is a reducing sugar. The correct answer is

The catalyst used for the isomerisation of n-alkanes to branched chain alkanes is:

The empirical formula weight of 'Z' in the given reaction sequence is
n-propyl bromide $ \xrightarrow{\text{Na}} $ X $ \xrightarrow{\text{V}_2\text{O}_5, 773 \, \text{K}} $ Y $ \xrightarrow{\text{Cl}_2, \, \text{UV}, 500 \, \text{K}} $ Z
Dry ether, 20 atm

Which one of the following compounds does not give benzoic acid when treated with alkaline $ KMnO_4 $?

At 700 K, the equilibrium constant $K_e$ for the reaction $ \text{N}_2(g) + 3\text{H}_2(g) \rightleftharpoons 2\text{NH}_3(g) $ is 0.2 mol L$^{-2}$. What is the value of $K$ for the reverse reaction?

Which one of the following gases is the major contributor to global warming?

At 25$^\circ$C, the percentage of ionization of x M acetic acid is 4.242. What is the pH of the acetic acid solution?
Given: $\log 4.242 = 0.6275$, $\log 0.04242 = -1.372$, $K_a = 1.8 \times 10^{-5}$

Observe the following reactions (g = gas):
I. N$_2$(g) + 3H$_2$(g) $\xrightarrow[\text{200 atm}]{\text{773K, X}}$ 2NH$_3$(g)
II. CO(g) + H$_2$O(g) $\xrightarrow[\text{673 K}]{\text{Y}}$ CO$_2$(g) + H$_2$(g)
III. CH$_4$(g) + H$_2$O(g) $\xrightarrow[\text{1270 K}]{\text{Z}}$ CO(g) + 3H$_2$(g)
Catalysts X, Y, Z respectively are

What is the molarity of a solution prepared by dissolving 10 grams of NaOH (molar mass = 40 g/mol) in 500 mL of solution?

The enthalpy of formation of $ \text{CO}_2(\text{g}) $ and $ \text{H}_2\text{O}(l) $ are $-393.5$ and $-286 \text{ kJ mol}^{-1}$ respectively. If the heat of combustion of $ \text{CH}_3\text{OH}(l) $ is $-749 \text{ kJ mol}^{-1}$, the enthalpy of formation of $ \text{CH}_3\text{OH}(l) $ $in \text{kJ mol}^{-1}$ is

Match the following