List of top Chemistry Questions

The polymer formed by \(X\) and \(Y\) is

At \(T\)(K), adsorption of gas \((A)\) on solid adsorbent \((B)\) follows Freundlich adsorption isotherm. On \(10\) g of \(B\), adsorption of gas \((A)\) gave the isotherm shown below. What is \(x\) (the quantity of \(A\) adsorbed in one gram of \(B\)) when the pressure of \(A\) is \(1.259\) atm?

\[ (\log 1.259=0.1,\qquad \text{Antilog}(0.1)=1.259) \]

\(\mathrm{XeF_4}\) on reaction with \(\mathrm{O_2F_2}\) at \(143\ \mathrm{K}\) gives a Xenon compound \(A\). On complete hydrolysis, \(A\) gives HF and \(B\). The hybridisation of the central atom in \(B\) is

Identify the pair of metals which are refined by zone refining method?

Which of the following reactions are correct with respect to the formation of products? I. \[ \mathrm{XeF_6+NaF\rightarrow Na[XeF_7]} \] II. \[ \mathrm{XeF_2+PF_5\rightarrow [XeF]^+[PF_6]^-} \] III. \[ \mathrm{XeF_4+SbF_5\rightarrow [XeF_3]^+[SbF_6]^-} \] The correct answer is

Which of the following statements are correct? I. Reaction of bromine with excess fluorine gives a T-shaped compound. II. Iodine oxides decompose on heating. III. Roasting of sulphide ores gives \(\mathrm{SO_2}\) as a byproduct. The correct answer is

The following reaction takes place in a galvanic cell at \(298\) K \[ \mathrm{Fe^{2+}(aq)+Ag^+(aq)\rightarrow Fe^{3+}(aq)+Ag(s)} \] The \(\Delta_rG^\circ\) (in kJ mol\(^{-1}\)) and \(\log K_c\) values are respectively \[ (F=96500\ \mathrm{C\,mol^{-1}},\; E^\circ_{\mathrm{Ag^+/Ag}}=0.80\ \mathrm{V},\; E^\circ_{\mathrm{Fe^{3+}/Fe^{2+}}}=0.77\ \mathrm{V},\; R=8.3\ \mathrm{J\,mol^{-1}K^{-1}}) \]

At \(T\)(K), the following data is obtained for the decomposition of \(A(g)\), which follows first order kinetics \[ A(g)\rightarrow B(g)+C(g) \] \[ \begin{array}{|c|c|} \hline \text{Time (s)} & \text{Total pressure (atm)} \hline 0 & 0.5 100 & 0.6 x & 0.65 \hline \end{array} \] What is \(x\) (in s)? \[ (\log1.25=0.097,\qquad \log1.4285=0.1549) \]

If two liquids \(A\) and \(B\) have \[ P_A^\circ:P_B^\circ=1:2 \] and have mole fraction in solution as \(1:2\), then mole fraction of \(B\) in vapour phase is

Observe the following reaction sequence and the statements given about the product \(Y\)

I. Reaction of \(Y\) with \(\mathrm{Br_2/UV}\) light forms aryl bromide.
II. Reaction of \(Y\) with \(\mathrm{CrO_3/(CH_3CO)_2O}\) followed by hydrolysis gives a compound which is acidic in nature.
The correct answer is

An alkene, \(\mathrm{C_4H_8}\) (\(X\)), on reaction with HBr gives a compound \(Y\). Hydrolysis of \(Y\) follows the \(S_\mathrm{N}1\) mechanism. The ozonolysis products of \(X\) are

A metal crystallizes in cubic lattice with edge length of \(4\ \text{\AA}\). The number of unit cells of this metal present in \(128\ \text{cm}^3\) volume is

Empirical formula weight of borazine is \[ (\text{At. wt: }H=1\ \text{u},\ B=10.8\ \text{u},\ N=14\ \text{u}) \]

Given below are two statements Statement-I: The solubility of \(\mathrm{CaCl_2}\) and \(\mathrm{MgCl_2}\) in water is more than that of \(\mathrm{NaCl}\). Statement-II: \(\mathrm{Ca(NO_3)_2}\) on heating gives three products. The correct answer is

IUPAC names of the following compounds \(X\) and \(Y\) are respectively

Which of the following reactions give hydrogen gas? \[ \begin{aligned} \text{I. }&\text{Reaction of tin with steam} \text{II. }&\text{Passage of steam over hot coke} \text{III. }&\text{Passage of air over hot coke} \end{aligned} \] The correct answer is

An alkene, \(X\) \((\mathrm{C_5H_{10}})\) exhibits cis/trans isomerism. Bromination of \(X\) followed by reaction with reagent(s) \(Y\) gave the product \(Z\). What are \(Y\) and \(Z\)?

The chemical prepared by Solvay's process is \(X\). The chemical prepared by Castner-Kellner process is \(Y\). \(X\) and \(Y\) are respectively

The pH of \(0.01\) M aqueous aniline solution at \(298\) K is \(8.3\). Its degree of dissociation \((\alpha)\) is \[ (K_b\text{ of aniline}=4\times10^{-10}; \ \text{antilog}(0.7)=5.0; \ \text{antilog}(0.3)=2.0; \ \text{antilog}(0.4)=2.5) \]

What is the enthalpy change (in kJ mol\(^{-1}\)) for the following reaction? \[ \mathrm{CH_4(g)\rightarrow C(g)+4H(g)} \] Given \[ \Delta_fH^\circ(\mathrm{CH_4})=-74.8\ \text{kJ mol}^{-1}, \] \[ \mathrm{H_2(g)\rightarrow 2H(g)};\qquad \Delta_aH^\circ=435\ \text{kJ mol}^{-1}, \] \[ \mathrm{C(s)\rightarrow C(g)};\qquad \Delta_aH^\circ=716.7\ \text{kJ mol}^{-1}. \]

How many of the following molecules ions are paramagnetic in nature? \[ \mathrm{N_2,\ O_2,\ F_2,\ NO,\ CO,\ O_2^-,\ O_2^{2-},\ N_2^+,\ NO^+,\ NO^-,\ H_2} \]

Consider the following \[ \mathrm{HF,\ H_2O,\ BeCl_2,\ CO_2,\ BF_3,\ NF_3,\ CCl_4,\ CHCl_3} \] The number of polar molecules is

In which of the following compounds, the size of manganese is maximum?

Which of the following is an endothermic process? \((g=\text{gas})\)

At \(T\)(K), the pressure of two ideal gases \(A\) and \(B\) is in the ratio \[ P_A:P_B=2:5. \] At this temperature, their densities are the same. The molar mass ratio \[ (M_A:M_B) \] is