Download App

Chemistry Assertion (A) & Reason (B) MCQ

Model Paper 6 · Gujarat Board (GSEB) STD 11 Science (GSEB - English Medium). 4 questions.

Questions

Assertion (A) & Reason (B) MCQ

Take a timed test

4 questions · auto-graded multiple-choice test.

MCQ 11 Mark
Assertion (A): Law of conservation of mass hold good for nuclear reaction.
Reason (R): Law states that mass can be neither created nor destroyed in a chemical reaction.
  • A
    Both A and R are true and R is the correct explanation of A.
  • B
    Both A and R are true but R is not the correct explanation of A.
  • C
    A is true but R is false.
  • ✓
    A is false but R is true.
Answer
Correct option: D.
A is false but R is true.
(d) A is false but R is true.
Explanation: Law of conservation of mass does not hold good for nuclear reaction due to mass defect.
View full question & answer→
MCQ 21 Mark
Assertion (A): Splitting of the spectral lines in the presence of a magnetic field is known as the Stark effect.
Reason (R): The line spectrum is simplest for the hydrogen atoms.
  • A
    Both A and R are true and R is the correct explanation of A.
  • B
    Both A and R are true but R is not the correct explanation of A.
  • C
    A is true but R is false.
  • ✓
    A is false but R is true.
Answer
Correct option: D.
A is false but R is true.
(d) A is false but R is true.
Explanation: Splitting of the spectral lines in the presence of a magnetic field is known as the Zeeman effect and in an electric field is known as the Stark effect. The splitting of spectral lines is due to different orientations which the orbitals can have in the presence of the magnetic field.
View full question & answer→
MCQ 31 Mark
Assertion (A): Both cyclopropane and propene give addition reactions readily.
Reason (R): Cyclopropane and propene are isomers of each other.
  • A
    Both A and R are true and R is the correct explanation of A.
  • ✓
    Both A and R are true but R is not the correct explanation of A.
  • C
    A is true but R is false.
  • D
    A is false but R is true.
Answer
Correct option: B.
Both A and R are true but R is not the correct explanation of A.
(b) Both $A$ and $R$ are true but $R$ is not the correct explanation of $A$.
Explanation: Propene being unsaturated undergoes addition reactions. In contrast, cyclopropane being strained readily undergoes ring cleavage to yield addition products.
View full question & answer→
MCQ 41 Mark
Assertion (A): Each carbon in ethylene molecule is $sp ^2$ hybridised.
Reason (R): The H-C-H bond angle in ethylene molecule is $120^{\circ}$.
  • A
    Both A and R are true and R is the correct explanation of A.
  • ✓
    Both A and R are true but R is not the correct explanation of A.
  • C
    A is true but R is false.
  • D
    A is false but R is true.
Answer
Correct option: B.
Both A and R are true but R is not the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A .
Explanation: Each carbon atom in ethylene is attached to two hydrogen atoms by single covalent bonds and to another carbon atom by a double bond. Since each carbon is attached to three other atoms, it uses $sp ^2$ hybrid orbitals and an unhybridised $p _{ z }$ orbital to form its bond. Each C-H bond is a $\sigma$ bond resulting from the overlap of 1 s orbital of hydrogen atom and $sp ^2$ orbital of a carbon atom. One C-C results from linear overlap of sp2 orbitals one from each carbon atom. One $\pi$ bond results from the lateral overlap o f two unhybridised $p _{ z }$ orbitals, one from each carbon atom.
View full question & answer→
Generate Paper FreeAll Model Paper 6 topics