Introduction to Chemical Changes and Reactions
Important Questions on Introduction to Chemical Changes and Reactions
State whether the following is a physical or chemical change. Explain by giving a reason.
Charging of car batteries.
State whether the following is a physical or chemical change. Explain by giving a reason.
Liquefying of air.
State whether the following is a physical or chemical change. Explain by giving a reason.
Ripening of fruits.
State whether the following is a physical or chemical change. Explain by giving reason.
Burning cow dung
State whether the following is a physical or a chemical change. Explain by giving a reason.
Heating copper sulphate crystals.
State whether the following is a physical or chemical change. Explain by giving reason.
Bursting of water pipes in winter.
State whether the following is a physical or chemical change. Explain by giving a reason.
Mixing sugar with tea.
State whether the following are physical or chemical changes. Explain by giving a reason.
Rusting of iron.
State whether the following is a physical or chemical change. Explain by giving reason.
Burning of charcoal
Mark True or False beside each sentence.
When an element undergoes a chemical change, its weight changes.
Mark True or False beside each sentence.
When heated iodine undergoes a physical change.
Mark True or False beside each sentence.
Energy is either evolved or absorbed in a chemical change.
A physical change alters the composition of a substance.
Mark True or False beside each sentence.
A chemical change is easily reversed.
Mark True or False beside each sentence.
When heated, undergoes a physical change.
Explain:
Chemical change
Explain:
Physical change
