List of top Chemistry Questions

Cite the name of the enzyme responsible for the following biochemical transformation: \[ C_6H_{12}O_6 (\text{Glucose}) \xrightarrow{\text{Enzyme}} 2C_2H_5OH + 2CO_2 (\text{Ethanol}) \]

An aqueous HCl solution has the pH = 5. If 1 ml of this solution is being diluted to 1 L, then predict the pH of the resulting solution.

1 molal NaCl solution has the density 1.21 gm/cc. Find the molar concentration of the same solution.

At 12°C and 756 mm atmospheric pressure, a balloon contains 450 ml air. If the balloon is shifted to a place of temperature 5°C and atmospheric pressure 765 mm, then indicate the nature (shape) and degree (volume) of change of the balloon.

At 30°C, a substance being dissolved in CCl$_4$ (solvent) exhibits its dissociation half-life as 2.5 hrs. If 256 g of the substance is taken initially, then tell how much of it will remain as such after 20 hrs.

In HF molecule, internuclear distance is 0.92 Å and dipole moment approximates 2 D. Estimate the percentage ionic character of HF molecule.

First ionisation potential energy of Li(m) is 520 kJ/mol$^{-1}$, hence calculate the energy required to convert Li-atoms present in 70 mg Li(m) into Li$^+$ ion.

Analyzing the following reaction, ascertain the final product:

How would you differentiate between $ \text{O}_3 $ and $ \text{H}_2\text{O}_2 $ (chemically)?

In solid state, nitrogen exists in two different allotropic forms ($\alpha$ and $\beta$). Give an idea regarding their shapes and stability.

Ascertain the products $B_1$ and $C_1$ of the following reaction:

Write the end product of the following reaction:

Identify the product(s) of the following two reactions (i) and (ii):

Upon addition of phenolphthalein to the aqueous solution of borax, pink colour generates i.e. solution becomes pink. At this stage, if glycerol is being added to the pink coloured solution, it turns colourless. Highlight the phenomenon.

In aqueous medium, cations like $ \text{H}^+ $ and $ \text{Li}^+ $ undergo hydration and exist in the hydrated form. Predict the numbers of water molecules surrounded with $ \text{H}^+ $ and $ \text{Li}^+ $ ions to form stable complex structure respectively.

In the contact process of manufacturing $\text{H}_2\text{SO}_4$, the arsenic purifier used in the industrial plant contains:

Trans-esterification is a reaction between

Which of the following compound(s) is/are chiral?

What is the integrated rate equation for a first-order reaction?

It is postulated that huge deposits of NaCl (rock salt) and CaCO3 (chalk and marble) are sites of erstwhile oceans, where the salts had been concentrated through weathering by rain and wind and leaching by rivers. Select the correct explanatory statement in this context.

Which of the following solutions, when mixed, will not form a buffer solution?

For the reaction:

$3Fe_{(s)} + 2O_2{(g)} \rightarrow Fe_3O_4{(s)}$

$\Delta H = -1650\,\text{kJ mol}^{-1}$, $\Delta S = -600\,\text{J K}^{-1} \text{mol}^{-1}$ at $300\,\text{K}$. What is the value of free energy change for the reaction at $300\,\text{K}$?

Identify the number of molecules having permanent dipole moment from the following: $$ CCl_4, NF_3, H_2S, HBr, SF_4, SiF_4, XeF_4, BeCl_2, SnCl_2, BrF_5, SO_2 $$

For the reaction: $$ 2A + B \rightarrow 2C + D $$ The following kinetic data were obtained for three different experiments performed at the same temperature: $$ \begin{array}{|c|c|c|c|} \hline \text{Experiment} & [A]_0 \, (\text{M}) & [B]_0 \, (\text{M}) & \text{Initial rate} \, (\text{M/s}) \\ \hline \text{I} & 0.10 & 0.10 & 0.10 \\ \text{II} & 0.20 & 0.10 & 0.40 \\ \text{III} & 0.20 & 0.20 & 0.40 \\ \hline \end{array} $$ The total order and order in $[B]$ for the reaction are respectively:

Which of the following is a non-biodegradable polymer?