Chemical reactions and Equations short 2

Question 1

Write the balanced chemical equation for Nitrogen and hydrogen when they combine to form ammonia ?

Answer 1

N^2 + 3 H^2 → 2 NH^3

Question 2

Write the balanced chemical equation when copper is dipped in the solution of silver nitrate ?

Answer 2

Cu + 2AgNO^3 → Cu(NO^3)2+ 2Ag

Question 3

Write the balanced chemical equation when Lead nitrate is heated ?

Answer 3

2 Pb [NO^3]2 → 2PbO + 4NO^2 + O^2

Question 4

What is the formula to achieve Slaked lime

Answer 4

CaO + H2O → Ca(OH)2 + Heat

Question 5

Give examples of combination reactions.

Answer 5

(i) Burning of coal
C + O2 → CO2 + heat
(ii) Formation of water from H2 and O2
2H^2 + O2 → 2H^2^O

Question 6

Give an example of thermal decomposition ?

Answer 6

CaCO3 Heat →CaO + CO2

Question 7

Give an example of a precipitate solution ?

Answer 7

Na^2SO^4 + BaCl^2 → BaSO^4 + 2NaCl

Question 8

A colorless lead salt when heated produces a yellow residue and brown flame
a) Name the lead salt
b) Name the brown fumes
c) Write a chemical equation of the reaction involved

Answer 8

a) The Salt : Lead Nitrate

b) Brown Fumes are Nitrogen Dioxide [NO^2]

c) Chemical equation : 2Pb[NO^3]2→2PbO + 4NO^2 + O^2

Question 9

Mg + Cuo → MgO + Cu. What reactions is this.

Answer 9

Redox as well as displacement as magnesium is more reactive then copper

Question 10

What type of reactions are decomposition usually ?

Answer 10

Endothermic