Class 9 Science - Chapter Is Matter Around Us Pure NCERT Solutions | Which of the following are chemical chan
Which of the following are chemical changes?
(a) Growth of a plant
(b) Rusting of iron
(c) Mixing of iron filings and sand
(d) Cooking of food
(e) Digestion of food
(f) Freezing of water
(g) Burning of a candle.
(a). Growth of a plant is a chemical change because at the time of photosynthesis, plants convert sunlight into chemical energy and this is an irreversible process.
(b). Rusting of iron is a chemical change because there is formation of new substance i.e.- Fe2O3, xH2O (Rust).
(c). Mixing of iron filings and sand is a physical change process.
(d). Cooking of food in a chemical change because there is change in chemical composition by supplying heat in addition to some food additives, oil, butter etc.
(e). Digestion of food is à chemical change because the enzyme present in stomach are break large macromolecules into simple molecules.
(f). Freezing of water is a physical change. because there is change in physical state of water notinitis composition.
(g). Burning of a candle is a chemical change because there is emission of CO2 and water vapours during the burning of candles.
More Questions From Class 9 Science - Chapter Is Matter Around Us Pure
- Q:-
How are sol, solution and suspension different from each other?
- Q:-
Name the technique to separate
(i) butter from curd,
(ii) salt from sea-water,
(iii) camphor from salt. - Q:-
Differentiate between homogeneous and heterogeneous mixtures with examples.
- Q:-
Identify the solutions among the following mixtures.
(a) Soil
(b) Sea water
(c) Air
(d) Coal
(e) Soda water. - Q:-
Explain the following giving examples.
(a) saturated solution
(b) pure substance
(c) colloid
(d) suspension - Q:-
List the points of differences between homogeneous and heterogeneous mixtures.
- Q:-
Classify the following into elements, compounds and mixtures.
(a) Sodium
(b) Soil
(c) Sugar solution
(d) Silver
(e) Calcium carbonate
(f) Tin
(g) Silicon
(h) Coal
(i) Air
(j) Soap
(k) Methane
(l) Carbon dioxide
(m) Blood - Q:-
Write the steps you would use for making tea. Use the words solution, solvent, solute, dissolve, soluble, insoluble, filtrate and residue.
- Q:-
Which of the following will show “Tyndall effect”?
(a) Salt solution
(b) Milk
(c) Copper sulphate solution
(d) Starch solution. - Q:-
Which of the following materials fall in the category of a “pure substance”?
(a) Ice
(b) Milk
(c) Iron
(d) Hydrochloric acid
(e) Calcium oxide
(f) Mercury
(g) Brick
(h) Wood
(i) Air.
Popular Questions of Class 9 Science
- Q:-
Which of the following has more inertia: (a) a rubber ball and a stone of the same size? (b) a bicycle and a train? (c) a five-rupees coin and a one-rupee coin?
- Q:-
State the universal law of gravitation.
- Q:-
Which of the following are matter?
Chair, air, love, smell, hate, almonds, thought, cold, cold-drink, smell of perfume.
- Q:-
A force of 7 N acts on an object. The displacement is, say 8 m, in the direction of the force (Fig. 11.3). Let us take it that the force acts on the object through the displacement. What is the work done in this case?
- Q:-
How does the sound produced by a vibrating object in a medium reach your ear?
- Q:-
In a reaction, 5.3 g of sodium carbonate reacted with 6 g of ethanoic acid. The products were 2.2 g of carbon dioxide, 0.9 g water and 8.2 g of sodium observations are in agreement with the law of conservation of mass.
sodium carbonate + ethanoic acid → sodium ethanoate + carbon dioxide + water
- Q:-
What are canal rays?
- Q:-
State any two conditions essential for good health.
- Q:-
How is our atmosphere different from the atmospheres on Venus and Mars?
- Q:-
Who discovered cells, and how?
Recently Viewed Questions of Class 9 Science
- Q:-
An object experiences a net zero external unbalanced force. Is it possible for the object to be travelling with a non-zero velocity? If yes, state the conditions that must be placed on the magnitude and direction of the velocity. If no, provide a reason.
- Q:-
Two children are at opposite ends of an aluminium rod. One strikes the end of the rod with a stone. Find the ratio of times taken by the sound wave in air and in aluminium to reach the second child.
- Q:-
When 3.0 g of carbon is burnt in 8.00 g oxygen, 11.00 g of carbon dioxide is produced. What mass of carbon dioxide will be formed when 3.00 g of carbon is burnt in 50.00 g of oxygen? Which law of chemical combination will govern your answer?
- Q:-
Na+ has completely filled K and L shells. Explain.
- Q:-
What does the odometer of an automobile measure?
- Q:-
Are the answers to the above questions necessarily the same or different? Why?
- Q:-
What is a tissue?
- Q:-
When a carpet is beaten with a stick, dust comes out of it. Explain.
- Q:-
Under which of the following conditions are you most likely to fall sick?
(a) when you are taking examinations.
(b) when you have travelled by bus and train for two days.
(c) when your friend is suffering from measles.Why?
- Q:-
What is the momentum of an object of mass m, moving with a velocity v?
(a) (mv)2 (b) mv2 (c) 1⁄2 mv2 (d) mv
- All Chapters Of Class 9 Science
- All Subjects Of Class 9