List of top Chemistry Questions

Enzymes that utilize ATP in phosphate transfer require an alkaline earth metal (M) as the cofactor. M is:

Styrene-butadiene elastomers $ (SBR) $ are the largest-volume synthetic rubber in the world. What is the ratio of butadiene : styrene in $ SBR $ ?

Extent of physisorption of a gas increases with _________ .

$ CHCl_3 $ is a polar solvent while $ CCl_4 $ is a non-polar solvent because $ CCl_4 $ has

The compound that is most difficult to protonate is:

4d, 5p, 5f and 6p orbitals are arranged in the order of decreasing energy. The correct option is :

Identify the correct statement(s):

A copper coin was electroplated with Zn and then heated at high temperature until there is a change in colour. What will be the resulting colour ?

The compound(s), capable of producing achiral compound on heating at 100°C is/are

Average atomic weight of an element M is 51.7. If two isotopes of $M, M^{50}$ and $M^{52}$ are present, then percentage of occurrence of $M^{50}$ in nature will be.

Eutrophication causes

1 L of 2 M CH3COOH is mixed with 1 L of 3M C2H5OH to form an ester. The rate of the reaction with respect to the initial rate when each solution is diluted with an equal volume of water will be

According to the VSEPR theory, the shape of $ClO_3^{-}$ would be

The Crystal Field Stabilisation Energy (CFSE) for $[CoCl_6]^{4-}$ is $18000\, cm^{-1}$. The CFSE for $[CoCl_4]^{2-}$ will be-

Which is the correct thermal stability order for $H_2E$ (E = O. S. Se. Te and $Po$) ?

Which of the following species is not stable ?

Which of the following is incorrect statement ?

The rate of radioactive disintegration at an instant for a radioactive same of half life $2.2 \times 10^9\,s^{-1}$ is $10^{10} \,s^{-1}$. The number of radioactive atoms in that sample at that instant is,

Which will make basic buffer?

A gas at 350 K and 15 bar has molar volume 20 percent smaller than that for an ideal gas under the same conditions. The correct option about the gas and its compressibility factor (Z) is :

The number of moles of solute present in the solutions of $I, II$ and $III$ is respectively I. $500 \,mL$ of $0.2\, M\, NaOH$ II. $200 \,mL$ of $0.1 \,N \,H _{2} SO _{4}$ II. $6 g$ of urea in $1 \,kg$ of water

Chlorine oxidises sulphur dioxide in the presence of water to give an oxyacid $A$. Chlorine also oxidises iodine in the presence of water to give an oxyacid $B$. The oxidation states of $S$ and $I$ in $A$ and $B$ are respectively

An organic compound $X\left( C _{7} H _{7} Cl \right)$ when reacted with $KCN / C _{2} H _{5} OH$ gave major product $Y . Z$ is formed when $Y$ is reduced with $LiAlH _{4}$. What are $Y$ and $Z$ ?

The wave functions of $1s$ orbitals of two hydrogen atoms are $\Psi_A$ and $\Psi_B$. $\Psi_A$ and $\Psi_B$ are linearly combined to form two molecular orbitals ($\sigma$ and $\sigma^{\ast}$). Which of the following statements are collect? I. $\sigma^{*}$ is equal to $(\Psi_{A}-\Psi_{B})$. II. In $\sigma$ - orbital, one nodal plane is present in between two nuclei. III. The energy of $\sigma$ - orbital is lower than the energy of $\sigma^{*}$ -orbital.

Identify $Z$ in the following sequence of reactions. $\ce{ C_2 H_4 Br_2 ->[(i) Alc.KOH][(ii) NaNH_2] X ->[Red\, hot][Fe \,tube\, 873 K] Y ->[(CH_3CO)_2 O/\Delta][Anhyd. AlCl_3] Z}$