List of top Chemistry Questions

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 $\left[\frac{{A}^-}{{HA}}\right]$?

Hydrated sodium aluminum silicate is called:

Which of the following are present in DNA?

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:

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

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

At STP $x$ g of a metal hydrogen carbonate (MHCO$_3$) (molar mass $84 \, {g/mol}$) on heating gives CO$_2$, which can completely react with $0.02 \, {moles}$ of MOH (molar mass $40 \, {g/mol}$) to give MHCO$_3$. The value of $x$ is:

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

At $ T(K) $, two liquids A and B form an ideal solution. The vapour pressures of pure liquids A and B at that temperature are 400 and 600 mm Hg respectively. If the mole fraction of liquid B is 0.3 in the mixture, the mole fractions of A and B in vapour phase respectively are:

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):

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$_3$.

Which of the following is correct statement?

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)

What are X and Y respectively in the following reactions?