List of top Chemistry Questions

IUPAC name of [Co(NH$_3$)$_4$(H$_2$O)Cl]Cl$_2$ is:

An alcohol 'X' (C$_4$H$_{10}$O) reacts with conc. HCl at room temperature and gives chloride. 'X' on dehydration followed by ozonolysis gives 'Y' and 'Z'. Find 'Y' and 'Z'.

Mole fraction of H$_2$SO$_4$ in aqueous solution is 0.9. Find mass % of H$_2$SO$_4$. (H=1, S=32, O=16 u)

First order reaction (A→P) with slopes mA, mB, mC at points A, B, C. Identify correct order.

Identify the crystal system in which body-centered lattice is not present.

At 298 K, equilibrium: M(s)+2Ag$^+$(aq)→M$^{2+}$(aq)+2Ag(s), K=10$^{15}$, ΔS=10 J/K. Find ΔrH (kJ/mol). FRT×2.303=0.06, F=96500 C/mol.

X and Y in reactions:

Increase in concentration of 'X' in blood of pregnant women who smoke may induce premature delivery. What is 'X'?

IUPAC names of benzene derivatives are respectively:

The reaction/s which represent the production of diborane on an industrial scale is/are:
I. 4BF$_3$ + 3LiAlH$_4$ → 2B$_2$H$_6$ + 3LiF + 3AlF$_3$
II. 2NaBH$_4$ + I$_2$ → B$_2$H$_6$ + 2NaI + H$_2$
III. 2BF$_3$ + 6NaH → B$_2$H$_6$ + 6NaF

Identify correctly matched sets:
I. NaHCO$_3$ - fire extinguisher
II. Na$_2$CO$_3$ - water softening
III. NaOH - purification of bauxite

Correct statements regarding halides of group 14 elements:
I. Stability of dihalides: SiX$_2$ > GeX$_2$ > SnX$_2$ > PbX$_2$
II. SnF$_4$, PbF$_4$ are ionic
III. PbI$_4$ does not exist

X and Y in reaction sequence:

Among alkaline earth metals, metal with least melting point is:

Identify the pairs in which both molecules do not possess same type of hybridization:
I. H$_2$O, SO$_2$
II. PCl$_3$, NH$_3$
III. SO$_2$, SO$_3$
IV. BCl$_3$, NCl$_3$

At 27$^\circ$C, 100 mL of 0.05 M Cu$^{2+}$ solution is added to 1 L of 0.1 M KI. Find [KI] in resultant solution.

Which of the following statements are correct?
I. The increasing order of covalent character of NaCl, RbCl, MgCl$_2$ is RbCl < NaCl <\ MgCl$_2$
II. The high boiling point of water is due to intramolecular hydrogen bonding
III. H$_2$O has more dipole moment among NH$_3$, H$_2$O, and HF

Isotherms ($p$-$V$ lines) of one mole of an ideal gas at $T_1$ and $T_2$ have slope ratio 1:2. If $T_1=1000$ K, find $T_2$.

Given $K_p$ for $2AO_2 + O_2 \rightleftharpoons 2AO_3$ is $4 \times 10^{10}$. Find $K_p'$ for $3AO_3 \rightleftharpoons 3AO_2 + \frac{3}{2} O_2$.

Identify the correct statements:
I. Energy of an isolated system is constant
II. In a closed system, exchange of both energy and matter is possible
III. Enthalpy is extensive

Which of the following is used as stabilizer for H$_2$O$_2$?

Ionization enthalpies of the elements X, Y, Z having successive atomic numbers respectively are 2080, 496, 737 kJ mol$^{-1}$. X, Y, Z are:

Observe the elements from H (Z=1) to Ca (Z=20). How many elements have no unpaired electrons in their ground state?

Among Li, Na, O, S, the elements having the most negative electron gain enthalpy and least negative electron gain enthalpy respectively are:

According to Bohr's theory of hydrogen atom, the approximate angular momentum of electron in H atom in the ground state is ($h = 6.62 \times 10^{-34}$ Js):