List of top Chemistry Questions

In the reaction, $C_{(s)} + O_{2(g)} \to CO_{2(g)}$

What is the effect of dilution on the equivalent conductance of strong electrolyte?

$4$ moles each of $S O_{2}$ and $O_{2}$ gases are allowed to react to form $SO_{3}$ in a closed vessel. At equilibrium $25 \%$ of $O_{2}$ is used up. The total number of moles of all the gases present at equilibrium is

A $5 \%$ solution (by mass) of cane sugar in water has freezing point of $271 \,K$ and freezing point of pure water is $273.15 \,K$. The freezing point of a $5 \%$ solution (by mass) of glucose in water is

The water pouch of instant cold pack for treating athletic injuries breaks when squeezed and $NH_4NO_3$ dissolves lowering the temperature. Addition of nonvolatile solute into solvent results into depression of freezing point of solvent.

$ 35.4\,\,mL $ of $ HCl $ is required for the neutralization of a solution containing $0.275 \,g$ of sodium hydroxide. The normality of hydrochloric add is?

Which of the following does not effect half-life of first order reaction?

Half-life of a substance is 6 min. If its initial amount is 32 g, then amount present after 18 minis:

The rate constant of a reaction is $2.3\times10^{-2} mol^{-2} L^{2} min^{-1}.$ The order of reaction is

The rate constant for a first order reaction whose half-life, is $480\, s$ is:

According to transition state theory, for the formation of an activated complex, one of the vibrational degrees of freedom is converted into a translational degree of freedom. Energy of the activated complex is higher than the energy of reactant molecules.

In a chemical reaction two reactants takes part. The rate of reaction is directly proportional to the concentration of one of them and inversely proportional to the concentration of the other. The order of reaction is:

Sodium pyrophosphate is represented by which of the following formula?

Which of the following statements is incorrect?

Density of a 2.05 M solution of acetic acid in water is 1.02 g/mL. The molality of the solution is:

Which of the following molecules/ions does not contain unpaired electrons ?

Molecular orbital theory was given by:

$CH_3Br+ Nu^- \to CH_3 - Nu + Br^-$ The decreasing order of the rate of the above reaction with nucleophiles $(Nu^-)$A to D is : $ [Nu^- = (A)PhO^-, (B)AcO^-, (C)HO^-,(D)CH_3O^-]$

Among the following which one can have a meso form?

The empirical formula of a compound is $CH _{2}$. One mole of this compound has a mass of $42\, g$. Its molecular formula is :

Which of the following statements is incorrect?

$ Ag^+ \, + NH_3 \rightleftharpoons [ Ag ( NH_3 ) ]^+ ; K_1 = 3.5 \times 10^{ - 3 } $ $ [ Ag ( NH_3 )]^+ \, + NH_3 \rightleftharpoons [ Ag (NH_3 )_2 ]^+ ; K_2 = 1.7 \times 10^{ - 3 } $ then the formation constant of $ [ Ag (NH_3)_2]^+ $ is...

Some chemists at ISRO wished to prepare a saturated solution of a silver compound and they wanted it to have the highest concentration of silver ion possible. Which of the following compounds, would they use? $K_{s p}( AgCl )=1.8 \times 10^{-10} $ $K_{s p}( AgBr )=5.0 \times 10^{-13} $ $K_{s p}\left( Ag _{2} CrO _{4}\right)=2.4 \times 10^{-12}$

$40\, ml$ of $0.1\, M$ ammonia solution is mixed with $20 \,ml$ of $0.1\, M\, HCl$. What is the $pH$ of the mixture? $\left( p K_{b}\right.$ of ammonia solution is $\left.4.74\right)$

Transition elements are generally used as catalyst because