Advertisements
Advertisements
Question
What is a chemical change? Give two examples of chemical change?
Solution
A chemical change is a permanent change in which the chemical composition of a substance is changed and a new substance is formed.
Examples:
Heating of copper carbonate
Formation of curd from milk
APPEARS IN
RELATED QUESTIONS
Define; catalyst.
What are (i) positive catalysts and (ii) negative catalysts? Support your answer with one example for each of them.
Write the missing reactants and products and balance the equations.
NaOH + ............... `→` NaCI + ...................
How is precipitate formation in a chemical reaction indicated?
Fill in the blank:
In some chemical reactions an insoluble ________ is formed when two solutions are mixed.
Write true or false :
When potassium iodide solution is added to lead acetate solution a red precipitate is formed.
Explain by writing a word equation.
Respiration is a chemical change.
Give reason for the following:
Silver nitrate solution is kept in coloured bottles.
What do you observe when HCI is passed through a silver nitrate solution.
Write your observation and a balanced equation in the case of the following substances being heated.
Zinc carbonate.
Distinguish by dilute sulphuric acid.
Sodium Sulphite and sodium carbonate?
Select the correct answer for the following options:
The black residue obtained on heating copper carbonate.
Give a word equation for the following reaction.
Two solids which combine on heating, to give a liquid.
Give a word equation for the following reaction.
Two gases which combine to give a solid.
Give a word equation for the following reaction.
A compound which on heating shows – colour change from brown to yellow.
Give reason for the following:
The catalytic oxidation of sulphur dioxide to sulphur trioxide is represented by a double arrow {⇌}
between the reactants and products, formed in the chemical reaction.
Complete the table given below.
Flame test for calcium chloride | Acid used for flame test |
Silver metal can displace hydrogen gas from nitric acid.
Is the conversion of milk into ice cream a chemical change?
Which is used as a catalyst during the process of hydrogenation of oils?