Chemical Reactions Based on Physical Contact

Give any two examples of chemical reactions on the basis of physical contact.

Which of the following is a must condition for a chemical reaction to occur?

When dry wood comes into contact with fire, it burns with the help of oxygen to form _____, which is given out as smoke.

When we put an iron nail in an open test tube containing water no reaction take place.

What happens when a matchstick is rubbed on the sides of a matchbox?

A chemical change is _____, _____ and produces _____. (temporary/permanent, reversible/Irreversible, new substance/no new substance)

Classify the following day to day activities based on chemical reactions by physical contact, solutions of reactants, heat, light, electricity and catalyst.

Copper vessel kept in open air for long time.

Classify the following day to day activities based on chemical reactions by physical contact, solutions of reactants, heat, light, electricity and catalyst.

Silver ornaments become black on exposure to air for a long time.

What is the primary purpose of using a catalyst in a reaction?

What can increase the surface area of a solid reactant in a reaction?

Which of the following is true for most catalytic reactions?

What happens when reactants are in a physical state that allows them to be in close contact?

What is one key difference between a chemical reaction with a catalyst and one without?

What is a feature of surface contact in a reaction?

How can the rate of reaction be increased in a reaction without using a catalyst?

In which type of reaction is a catalyst often used to speed up the process?

What is a common characteristic of all catalytic reactions?

What does physical contact do in a reaction between two solids?

How does the presence of a catalyst affect the energy required for a reaction?

Which of the following is true about a catalytic reaction?