STANDARD Chemistry Class 11 Questions

The number of chain isomers possible for hydrocarbon C₅H₁₂ is

A reaction is said to be in equilibrium when

Which of the following statements is not true?

The nucleus of helium contains

Which of the following represents the given sequence of hybridisation of carbon atoms from left to right sp², sp², sp, sp?

A real gas behaves like an ideal gas if its

System in which there is no exchange of matter, work or energy from surroundings is

U = q + w, is mathematical expression for

The hybridisation of carbons of C – C single bond of HC ≡ C – CH = CH₂ is

Study the given figure and label X, Y and Z.

Wurtz reaction may be used to unite

Which of the following is not a redox reaction?

The number of electrons and neutrons of an element is 18 and 20 respectively. Its mass number is

A mixture of 1-iodoethane and 1-iodopropane is treated with sodium metal and dry ether to carry out Wurtz reaction. Which of the following hydrocarbons will be formed?

The work done during the expansion of a gas from 4 dm³ to 6 dm³ against a constant external pressure of 3 atm is (1 L atm = 101.32 J)

Which species is acting as a reducing agent in the following reaction? 14H⁺ + Cr₂O₇²⁻ + 3Ni → 2Cr³⁺ + 7H₂O + 3Ni²⁺

Two stable isotopes ⁶Li and ⁷Li have respective abundances of 7.5% and 92.5%. These isotopes have masses 6.01512 u and 7.01600 u respectively. The atomic weight of lithium is

An isotone of ⁷⁶₃₂Ge is

An alkene CH₃CH = CH₂ is treated with B₂H₆ in presence of H₂O₂. The final product formed is

If w is the amount of work done by the system and q is the amount of heat supplied to the system, identify the type system of the system.

Which alkane is produced when sodium salt of butanoic acid is heated with soda lime?

The natural boron of atomic weight 10.81 is found to have two isotopes ¹⁰B and ¹¹B. The ratio of abundance of isotopes of natural boron should be

Which one is the wrong statement

A process is called reversible when

Cumene on reaction with oxygen followed by hydrolysis gives

For an isothermal reversible expansion process, the value of q can be calculated by the expression

According to VSEPR theory,

The reaction, CH₂=CH−CH₃ + HBr → CH₃−CHBr−CH₃ is an example of

In an adiabatic expansion of ideal gas

The shape of water molecule which should be tetrahedral has a bent or distorted tetrahedral shape with a bond angle 104.5°. What could be the reason for this?

The negative part of the addendum (the molecule to be added) adds on to the carbon atom of the double bond containing the least number of hydrogen atoms. This rule is known as

Two litres of an ideal gas at a pressure of 10 atm expands isothermally into a vacuum until its total volume is 10 litres. How much heat is absorbed and how much work is done in the expansion?

Which step is chain propagation step in the following mechanism? (i) Cl₂ → hν → Cl• + Cl• (ii) Cl• + CH₄ → •CH₃ + HCl (iii) Cl• + Cl• → Cl₂ (iv) •CH₃ + Cl → CH₃Cl

In Balmer series of emission spectrum of hydrogen, first four lines with different wavelength Hα, Hβ, Hγ and Hδ are obtained. Which line has maximum frequency out of these?

The enthalpy change of a reaction does not depend upon

Which of the following reactions follows Markovnikov’s rule?

The magnetic moment of a divalent ion in aqueous solution with atomic number 25 is

Consider the given diagram for 1 mole of a gas X and answer the following question. The process A → B represents

Identify the products X and Y formed in the following reaction. CH₃—CH₂—CH=CH—CH₃ + HCl → X + Y

Match the column I with column II to identify the products of oxidation of alkanes and mark the appropriate choice.

The wavelength of radiation emitted is λ₀ when an electron jumps from the third to second orbit of hydrogen atom. For the electron jumping from the fourth to the second orbit of the hydrogen atom, the wavelength of radiation emitted will be

Match the molecules given in column I with their shapes given in column II and mark the appropriate choice.

Which of the following relationships is not correct for the relation between ΔH and ΔU?

The shortest wavelength in the Balmer series is (R = 1.097 × 10⁷ m⁻¹)

Few reactions of alkanes are given below. Identify the name of the reaction which is not correctly matched with the reaction.

Carbon is in the lowest oxidation state in

In the given reactions: (i) CH₃Br − Na, ether → X − Br₂, hv → Y − Na, ether → Z (ii) CH₃COOH − NaOH, CaO → X − NaOH, CaO → Y − Br₂, hv → Z Identify X, Y and Z.

The statements (i) In filling a group of orbitals of equal energy, it is energetically preferable to assign electrons to empty orbitals rather than pair them into a particular orbital. (ii) When two electrons are placed in two different orbitals, energy is lower if the spins are parallel. are valid for

According to the first law of thermodynamics, ΔU = q + w. In special cases the statement can be expressed in different ways. Which of the following is not a correct expression?

Which of the following does not show octahedral geometry?