List of top Chemistry Questions

The starting material for convenient preparation of deuterated hydrogen peroxide \(\left(D_2 O _2\right)\) in laboratory is :

Which of the following statements is correct about freons?

The effect of addition of helium gas to the following reaction in equilibrium state, is : \(PCl _5( g ) \rightleftharpoons PCl _3( g )+ Cl _2( g )\)

\(H_2O_2\) behave like reducing agent in which of the following reactions:

S1: Be+2 has higher SRP than other alkaline earth metals.
S2: Be+2 has higher hydration energy and greater △aH (atomisation enthalpy) than other alkaline earth metals.

\([Co(NH_3)_6]^{3+} \text{is} \) ________\(\text{hybridised and}\)________
The metal which is extracted by oxidation and subsequent reduction from its ore is:

Given below are two statements, one is labelled as Assertion A and the other is labelled as Reason R 
Assertion (A) : Benzene is more stable than hypothetical cyclohexatriene 
Reason (R) : The delocalised π-electrons cloud is attracted more strongly by the nuclei of the carbon atoms than the electron cloud localised between two carbon atoms.
In the light of the above statements, choose the correct answer from the options given below

Which one amongst the following are good oxidizing agents?
(A) \( \text{Sm}^{\text{2+}}\)
(B) \(\text{Ce}^{\text{2+}}\)
(C)\( \text{Ce}^{\text{4+}}\)
(D) \(\text{Tb}^{\text{4+}}\)
Choose the most appropriate answer from the options given below:

For which of the following aqueous ion, spin only magnetic moment is 3.87 BM?

\(A(g) ⇋ 2B(g) + C(g)\)
For the given reaction, if the initial pressure is 450 mm Hg and the pressure at time t is 720 mm Hg at a constant temperature T and constant volume V. The fraction of A(g) decomposed under these conditions is \(x × 10^{–1}\). The value of x is _____ . (nearest integer)
In alkaline medium, the reduction of permanganate anion involves a gain of _____ electrons.
The electron in the \(n^{th}\) orbit of \(Li^{2+}\) is excited to \((n + 1)\) orbit using the radiation of energy \(1.47 × 10^{–1}J \) (as shown in the diagrarn). The value of n is ______ .
Given: \(R_H = 2.18 × 10^{–18} J\).
The number of incorrect statement/s from the following is ____ .
A. The successive half lives of zero order reactions decreases with time.
B. A substance appearing as reactant in the chemical equation may not affect the rate of reaction.
C. Order and molecularity of a chemical reaction can be a fractional number.
D. The rate constant units of zero and second order reaction are mol L–1s–1 and mol–1 Ls–1 respectively.
During the reaction of permanganate with thiosulphate, the change in oxidation of manganese occurs by value of 3. Identify which of the below medium will favour the reaction
The number of endothermic process/es from the following is _____ .
A. \(I_2 (g) → 2I (g)\)
B. \(HCl (g) → H(g) + Cl (g)\)
C. \(H_2O(l) → H_2O (g)\)
D. \(C(s) + O_2 (g) → CO_2 (g)\)
E. Dissolution of ammonium chloride in water.
The difference in the oxidation state of \(Xe\) between the oxidised product of \(Xe\) formed on complete hydrolysis of \(XeF_4\) and \(XeF_4\) is _____ .
An aqueous solution of volume 300 cm3 contains 0.63 g of protein. The osmotic pressure of the solution
at 300 K is 1.29 mbar. The molar mass of the protein is ____ g mol–1.
Given: R = 0.083 L bar K–1 mol–1
The specific conductance of 0.0025 M acetic acid is \(5 × 10^{–5} S\ cm^{–1}\) at a certain temperature. The dissociation constant of acetic acid is ___________ \(× 10^{–7}.\) (Nearest integer) Consider limiting molar conductivity of \(CH_3COOH\) as \(400\  S cm^2 mol^{–1}\).
The number of molecules from the following which contain only two lone pair of electrons is _____ .
\(H_2O, N_2, CO, XeF_4, NH_3, NO, CO_2, F_2\)
Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R:
Assertion A: 3.1500 g of hydrated oxalic acid dissolved in water to make 250.0 mL solution will result in 0.1 M oxalic acid solution.
Reason R: Molar mass of hydrated oxalic acid is 126 g mol–1.
In the light of the above statements, choose the correct answer from the options given below.
Which one of the following elements will remain as liquid inside pure boiling water?
Ferric chloride is applied to stop bleeding because-
The major product P formed in the given reaction is:
The major product P formed
Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R:
Assertion A: The energy required to form \(Mg^{2+}\) from Mg is much higher than that required to produce \(Mg^+\)
Reason R: \(Mg^{2+}\) is small ion and carry more charge than \(Mg^{+}\).
In the light of the above statements, choose the correct answer from the options given below.