List of top Chemistry Questions

The number of –OH groups in open chain and ring structures of D-glucose are respectively

The bond lengths of diatomic molecules of elements X, Y, and Z respectively are 143, 110, and 121 pm. The atomic numbers of X, Y, and Z respectively are:

Two statements are given below:
I. SO₂ is used as antioxidant in wine
II. BHA is used as food preservative in dry fruits

The dissociation constants of a diacid HA are $K_{a1} = 6 \times 10^{-2}$ and $K_{a2} = 6 \times 10^{-5}$. The pH of 0.011 M $HA$ solution is 2.0. What is the value of $\left[\frac{{A}^-}{{HA}}\right]$?

p-Methyl benzene nitrile can be prepared from which of the following?

A mixture of ethyl iodide and n-propyl iodide is subjected to Wurtz reaction. The hydrocarbon which will not be formed is:

Aniline on direct nitration at 288 K gives 51% (A), 47% (B) and 2% (C). ‘B’ on diazotisation, followed by reaction with CuCN | KCN gives a compound X. The percentage of nitrogen in X is:

At 300 K, for the reaction, \[ \text{A}_2 \text{B}_2(g) \rightleftharpoons \text{A}_2(g) + \text{B}_2(g) \]
$\text{is 100 mol L}^{-1}$. $\text{What is its } K_p \text{(in atm)} \text{at the same temperature?} $
$\text{(R = 0.082 L atm mol}^{-1}$ $\text{K}^{-1}) $

Identify the correct equation relating $ \Delta H $, $ \Delta U $, and $ \Delta T $ for 1 mole of an ideal gas (R = gas constant):

What are X and Y respectively in the following reactions?

Arrange the following in the correct order of their acidic strength: I. $ \text{C}_6 \text{H}_4 (\text{OH}) $ (I) II. $ \text{C}_6 \text{H}_5 (\text{OH}) $ (II) III. $ \text{C}_6 \text{H}_4 (\text{NO}_2)(\text{OH}) $ (III) IV. $ \text{C}_6 \text{H}_4 (\text{NO}_2)(\text{OH}) $ (IV)

The number of molecules having one lone pair of electrons on the central atom is from the following list: SnCl$_2$, XeF$_6$, SO$_3$, ClF$_3$, BrF$_5$, H$_2$O, XeO$_3$.

Identify the incorrect set from the following:

Which of the following is correct statement?

Which complex among the following is most paramagnetic?

The product of which of the following reactions undergo hydrolysis by SN1 mechanism?

Ba, Ca, Sr form halide hydrates. Their formulae are $ BaCl_2 \cdot xH_2O $, $ CaCl_2 \cdot yH_2O $, $ SrCl_2 \cdot zH_2O $. The values of $ x, y, z $ respectively are:

The equilibrium constant for the dissociation of HI at 773 K is:

What is Y in the following reaction sequence?

For a first-order reaction, the concentration of reactant was reduced from 0.03 mol L$^{-1}$ to 0.02 mol L$^{-1}$ in 25 min. What is its rate (in mol L$^{-1}$ s$^{-1}$)?

What are the variables in the graph of powder diffraction pattern of a crystalline solid?

The correctly matched set of the following is:

50 mL of 1 M HCl was completely reacted with $x$ g of CaCO3 to form CaCl2, CO2, and H2O. What is the value of $x$ in g?

Which of the following is a lung irritant?

Observe the following set of reactions:

Correct statement regarding Y and B is: