List of top Chemistry Questions asked in CBSE Class XI

Arrange the following metals in the order in which they displace each other from the solution of their salts.
Al, Cu, Fe, Mg and Zn.
Calculate the pH of the resultant mixtures: 
a) 10 mL of 0.2M Ca(OH)2 + 25 mL of 0.1M HCl 
b) 10 mL of 0.01M H2SO4 + 10 mL of 0.01M Ca(OH)2
c) 10 mL of 0.1M H2SO4 + 10 mL of 0.1M KOH
The ionic product of water at 310 K is 2.7 × 10–14. What is the pH of neutral water at this temperature?
Given the standard electrode potentials,
K+ /K = -2.93V,
Ag+/Ag = 0.80V, 
Hg2+/Hg = 0.79V 
Mg2+/Mg = -2.37V.
Cr3+/Cr = -0.74V
Arrange these metals in their increasing order of reducing power.
Depict the galvanic cell in which the reaction Zn(s) + 2Ag+ (aq) \(\rightarrow\)  Zn2+ (aq) + 2Ag(s) takes place, further show: 
  1. which of the electrode is negatively charged, 
  2. the carriers of the current in the cell, and
  3. individual reaction at each electrode.
Write IUPAC names of the following compounds:
IUPAC names of the following compounds
Fluorine reacts with ice and results in the change:
\(H_2O(s) + F_2{(g)} \rightarrow HF{(g)} + HOF{(g)}\) Justify that this reaction is a redox reaction.
While sulphur dioxide and hydrogen peroxide can act as oxidising as well as reducing agents in their reactions, ozone and nitric acid act only as oxidants. Why?
Suggest a list of the substances where carbon can exhibit oxidation states from -4 to +4 and nitrogen from -3 to +5.
Write the formulae for the following compounds: 
(a) Mercury (II) chloride (b) Nickel (II) sulphate 
(c) Tin (IV) oxide (d) Thallium (I) sulphate 
(e) Iron (III) sulphate (f) Chromium (III) oxide
The ionization constant of chloroacetic acid is 1.35 × 10–3. What will be the pH of 0.1M acid and its 0.1M sodium salt solution?
Predict if the solutions of the following salts are neutral, acidic or basic: NaCl, KBr, NaCN, NH4NO3, NaNO2 and KF
A 0.02M solution of pyridinium hydrochloride has pH = 3.44. Calculate the ionization constant of pyridine.
The ionization constant of nitrous acid is 4.5 × 10–4. Calculate the pH of 0.04 M sodium nitrite solution and also its degree of hydrolysis.
The pH of 0.1M solution of cyanic acid (HCNO) is 2.34. Calculate the ionization constant of the acid and its degree of ionization in the solution.
The solubility of Sr(OH)2 at 298 K is 19.23 g/L of solution. Calculate the concentrations of strontium and hydroxyl ions and the pH of the solution.
If 0.561 g of KOH is dissolved in water to give 200 mL of solution at 298 K. Calculate the concentrations of potassium, hydrogen and hydroxyl ions. What is its pH?
The pH of milk, black coffee, tomato juice, lemon juice and egg white are 6.8, 5.0, 4.2, 2.2 and 7.8 respectively. Calculate corresponding hydrogen ion concentration in each.
The ionization constant of propanoic acid is 1.32 × 10–5. Calculate the degree of ionization of the acid in its 0.05M solution and also its pH. What will be its degree of ionization if the solution is 0.01M in HCl also?
Why is benzene extra ordinarily stable though it contains three double bonds?
Calculate the hydrogen ion concentration in the following biological fluids whose pH are given below: 
(a) Human muscle-fluid,6.83 
(b) Human stomach fluid,1.2 
(c) Human blood,7.38 
(d) Human saliva,6.4
Write chemical equations for combustion reaction of the following hydrocarbons:
  1. Butane
  2. Pentene
  3. Hexyne
  4. Toluene
Draw the cis and trans structures of hex-2-ene. Which isomer will have higher b.p. and why?
Propanal and pentan-3-one are the ozonolysis products of an alkene? What is the structural formula of the alkene?
An alkene ‘A’ contains three C – C, eight C – H σ bonds and one C – C \(\pi\) bond. ‘A’ on ozonolysis gives two moles of an aldehyde of molar mass 44 u. Write IUPAC name of ‘A’.