Chemical Reaction

Q. (A) \( + \) BC \( \rightarrow \) AC \( + \) B ii) (AB \( + \) CD \( \rightarrow \) AC \( + \) BD
Identify the types of reaction mentioned above in (i) and (ii). Give one example for each type in the form of a balanced chemical equation.

[3 Marks]

Q. State true or false. Sometimes, just mixing the reactants may not be enough for a chemical reaction to happen.

1. True
2. False

Q.

A chemical reaction involves __________.

1. Only breaking of bonds

2. Only formation of bonds

3. Both breaking and formation of bonds

4. None of the given options

Q. Raghu while performing experiments found that the speed of the chemical reaction increases as the surface area of the reactant is increased. Why is it happening so?

1. This change alters the electrical conductivity of the reactant particle.
2. This change increases the density of the reactant particles.
3. This change increases the concentration of the reactant.
4. This change exposes more reactant particles to possible collisions.

Q.

$S{O}_2$ and $S{O}_3$ represents the same compound.True/False

1. True

2. False

Q.

What does $2H_{2}O$ represent?

1. 2 molecules of water

2. 6 atoms in total

3. 6 atoms in total or 2 molecules of water

4. 4 atoms in total or 2 molecules of water

Q.

Which of the following are correct with respect to chemical reactions?
(i) Chemical compositon changes
(ii) Formation of new products takes place
(iii) We can’t obtain the intial reactants by simple physical means like filtering, dissolving etc.

1. Formation of new products takes place

2. Chemical compositon changes

3. We can’t obtain the intial reactants by simple physical means like filtering, dissolving etc.

4. All of these

Q.

The atomicity of the molecule $X_2(ZY{S}_4{)}_3$ is __.

Q.

A __ is a substance which changes the rate of a chemical reaction without itself undergoing any chemical change.

Q.

Atomicity is the number of atoms present in a molecule.

1. True

2. False