Why is respiration considered an exothermic process?

Important Questions on Chemical Reactions and Equations

HARD

10th CBSE

IMPORTANT

Core Science Chemistry>Chapter 1 - Chemical Reactions and Equations>EXERCISE 1B>Q 5

By adding dilute hydrochloric acid to copper oxide powder. The solution formed is bluish green. Predict the new compound formed that imparts the colour to the solution.

MEDIUM

10th CBSE

IMPORTANT

Core Science Chemistry>Chapter 1 - Chemical Reactions and Equations>EXERCISE 1B>Q 6

In electrolysis of water, why is the volume of hydrogen collected over one electrode double than that of the gas collected over other electrode.

MEDIUM

10th CBSE

IMPORTANT

Core Science Chemistry>Chapter 1 - Chemical Reactions and Equations>EXERCISE 1B>Q 7

Why do we store silver chloride in dark coloured bottles?

MEDIUM

10th CBSE

IMPORTANT

Core Science Chemistry>Chapter 1 - Chemical Reactions and Equations>EXERCISE 1B>Q 1

A silver article generally turns black when kept in open for few days. The article when rubbed with toothpaste again starts shining.

Why do sliver articles turn black when kept in the open for a few days? Name the phenomenon involved.

MEDIUM

10th CBSE

IMPORTANT

Core Science Chemistry>Chapter 1 - Chemical Reactions and Equations>EXERCISE 1B>Q 1

A silver article generally turns black when kept in open for few days. The article when rubbed with toothpaste again starts shining.

Name the black substance formed and give its chemical formula.

MEDIUM

10th CBSE

IMPORTANT

Core Science Chemistry>Chapter 1 - Chemical Reactions and Equations>EXERCISE 1B>Q 2

A magnesium ribbon is burnt in oxygen to give a white compound X accompanied by emission of light. If the burning ribbon is now placed in an atmosphere of nitrogen, it continues to burn and forms a compound Y.

Write the chemical Formula of X and Y.

MEDIUM

10th CBSE

IMPORTANT

Core Science Chemistry>Chapter 1 - Chemical Reactions and Equations>EXERCISE 1B>Q 2

A magnesium ribbon is burnt in oxygen to give a white compound X accompanied by emission of light. If the burning ribbon is now placed in an atmosphere of nitrogen, it continues to burn and forms a compound Y.
Write a balanced chemical equation, when X is dissolved in water

HARD

10th CBSE

IMPORTANT

Core Science Chemistry>Chapter 1 - Chemical Reactions and Equations>EXERCISE 1B>Q 3

A substance X, which is an oxide of a group 2 element, is used intensively in the cement industry. This element is present in bones also. On treatment with water it forms a solution that turns red litmus blue. Identify X and also write the chemical reactions involved.