Why do fireflies glow at night?

Important Questions on Chemical Reactions and Equations

HARD

10th CBSE

IMPORTANT

Core Science Chemistry>Chapter 1 - Chemical Reactions and Equations>EXERCISE 1B>Q 12

Grapes hanging on the plant do not ferment but after being plucked from the plant can be fermented. Under what condition do these grapes ferment? Is it a chemical or a physical change?

HARD

10th CBSE

IMPORTANT

Core Science Chemistry>Chapter 1 - Chemical Reactions and Equations>EXERCISE 1B>Q 13

An aluminium can is used to store ferrous sulphate solution. It is observed that in a few days holes appear in the can. Explain the observation and write the chemical equation in support of your answer.

HARD

10th CBSE

IMPORTANT

Core Science Chemistry>Chapter 1 - Chemical Reactions and Equations>EXERCISE 1B>Q 14

Ferrous sulphate decomposes with evolution of gas having a characteristic odour of burning sulphur. Write the chemical reaction involved and identify the type of reaction.

HARD

10th CBSE

IMPORTANT

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

Complete the missing components/variables given as x and y in the following reactions:
$\mathrm{Pb}{\left({\mathrm{NO}}_3\right)}_2\left(\mathrm{aq}\right)+2\mathrm{KI}\left(\mathrm{aq}\right){\mathrm{PbI}}_2\left(\mathrm{x}\right)+2{\mathrm{KNO}}_3\left(\mathrm{y}\right)$

MEDIUM

10th CBSE

IMPORTANT

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

Complete the missing component/variable given as x in the following reaction.
$\mathrm{Cu}\left(\mathrm{s}\right)+2\mathrm{Ag}{\left({\mathrm{NO}}_3\right)}_2\left(\mathrm{aq}\right)\to \mathrm{Cu}{\left({\mathrm{NO}}_3\right)}_2\left(\mathrm{aq}\right)+\mathrm{x}\left(\mathrm{s}\right)$

HARD

10th CBSE

IMPORTANT

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

Complete the missing components/variables given as x and y in the following reaction.
$\mathrm{Zn}\left(\mathrm{s}\right)+{\mathrm{H}}_2{\mathrm{SO}}_4\left(\mathrm{aq}\right)\to {\mathrm{ZnSO}}_4\left(\mathrm{x}\right)+{\mathrm{H}}_2\left(\mathrm{y}\right)$

HARD

10th CBSE

IMPORTANT

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

The given change below is exothermic or endothermic in nature?
Decomposition of ferrous sulphate

MEDIUM

10th CBSE

IMPORTANT

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

The given change below is exothermic or endothermic in nature?
Dilution of sulphuric acid