ICSE ICSE Class 7 - CISCE Question Bank Solutions

Write word equation for the following molecular equation:

\[\ce{N2 + 3H2 ⇌[Fe - 450°C][200 atoms] 2NH3 + \triangle}\]

Word equation:
State why [+ Δ] indication is seen after NH₃.
State what 200 atmospheres – indicates.
State the function of Fe in the above reaction.

Write word equation for the following molecular equation:

\[\ce{H2 [g] + Cl2 [g] ->[sunlight] 2HCl}\]

Word equation:

State which form of energy is utilised in the above chemical reaction.

Write word equation for the following molecular equation:

AgN0₃ + HCI → HNO₃ + AgCl ↓

Word equation:

State whether AgCl is soluble or insoluble in HN0₃.

Write word equation for the following molecular equation:

CaO + H₂0 → Ca (OH)₂ + Δ

Word equation:

State why [+ Δ ] is not written in the reaction, if ZnO reacts with H2O.

Write word equation for the following molecular equation:

\[\ce{CuSO4 + 2NaOH -> Na2SO4 + Cu(OH)2↓}\]

Word equation:

State the colour of the products.

Define the Solid and give two examples.

Define the Liquid and give two examples.

Define the Gas and give two examples.

A chemical reaction is generally accompanied by certain external indications or characteristics. These include – change of – (a) colour (b) state (c) smell (d) evolution of gas (e) formation of precipitate (f) evolution or absorption of heat. With reference to change of colour – state the change in colour seen when the following are heated – copper carbonate.

A chemical reaction is generally accompanied by certain external indications or characteristics. These include – change of – (a) colour (b) state (c) smell (d) evolution of gas (e) formation of precipitate (f) evolution or absorption of heat. With reference to change of colour – state the change in colour seen when the following are heated – zinc carbonate.

A chemical reaction is generally accompanied by certain external indications or characteristics. These include – change of – (a) colour (b) state (c) smell (d) evolution of gas (e) formation of precipitate (f) evolution or absorption of heat. With reference to change of colour – state the change in colour seen when the following are heated – mercury [II] oxide.

A chemical reaction is generally accompanied by certain external indications or characteristics. These include – change of – (a) colour (b) state (c) smell (d) evolution of gas (e) formation of precipitate (f) evolution or absorption of heat. With reference to change of colour – state the change in colour seen when the following are heated –  lead [IV] oxide.

Give a balanced equation for addition of iron to copper [II] sulphate solution. State the change in colour seen.

In certain reaction a change of state is observed i.e. solid to liquid, liquid to gas etc. – State the change of state of the products – to give the respective reactant.

\[\ce{C +2S -> CS2}\]

In certain reaction a change of state is observed i.e. solid to liquid, liquid to gas etc. – State the change of state of the products – to give the respective reactant.

NH₃ + HCl ⇌ NH₄Cl 

Name the three states of matter.

In certain reaction a change of state is observed i.e. solid to liquid, liquid to gas etc. – State the change of state of the products – to give the respective reactant.

2H₂ + O₂ → 2H₂O

On what basis are the three states classified of matter.

In certain reaction a change of state is observed i.e. solid to liquid, liquid to gas etc. – State the change of state of the products – to give the respective reactant.

\[\ce{2H2O ->[electric][current] 2H2 + O2}\]

Each of the three states of matter has mass. Explain with the help simple experiments – that each state of matter has mass.