Drying of paint is a physical or chemical change ?
Important Questions on Chemical Changes and Reactions
State whether the following is a physical or chemical change. Explain by giving reason.
Burning cow dung
Which one of the following substances does not undergo a chemical change on heating:
Complete the following statements by using proper words:
The temperature at which a solid changes into a liquid is called _____.
State whether the following is a physical or chemical change. Explain by giving a reason.
Liquefying of air.
Fill in the blanks with the correct answer in the following statement:
A _____ change is one in which one or more different substances are formed.
Ravi tested both the above liquids and found that these two differ in their odour as well as in inflammability. The former one is highly inflammable while the latter is used to extinguish fire. He predicts such a difference is due to difference in their
Sonu wanted to react potassium iodide solution with aqueous solution of lead nitrate to obtain a yellow precipitate of lead iodide. To carry out the reaction, he made the following experimental set up.
But accidently the lead nitrate solution fall down and more lead nitrate is not available in the laboratory. Could you suggest which of the following salt he can use for performing this activity?
Complete the following statement by using proper word:
The process of a solid changing directly into a gas is called _____.
State whether the following is a physical or chemical change. Explain by giving a reason.
Ripening of fruits.
Fill in the blanks with the correct answer in the following statement:
A _____ can easily be reversed.
Fill in the blanks with the correct answers in the following statement:
Dissolving common salt in water is an example of a _____ change.
Dissolving zinc in dilute is an example of a _____ change. (natural / chemical)
Complete the following statements by using proper words:
A change which alters the composition of a substance is known as a _____ change.
