Advertisements
Advertisements
Question
Which one of the following is not a chemical change ?
Options
formation of curd
ripening of banana
sublimation of naphthalene
corrosion of photo frame
Solution
sublimation of naphthalene
Sublimation of naphthalene is not a chemical change because it only allows naphthalene to change its state from solid to vapour. No new compound is formed and the vapour can again be condensed to solid form.
APPEARS IN
RELATED QUESTIONS
Select the correct alternative
The molecules can move freely anywhere in
- gases
- liquids
- solids
- none of the above
Name the processes involved in two cases.
Which of the following materials fall in the category of a “pure substance”?
- Ice
- Milk
- Iron
- Hydrochloric Acid
- Calcium oxide
- Mercury
- Brick
- Wood
- Air
Classify the following into elements, compounds and mixtures:
- Sodium
- Soil
- Sugar solution
- Silver
- Calcium carbonate
- Tin
- Silicon
- Coal
- Air
- Soap
- Methane
- Carbon dioxide
- Blood
Name a metal which is soft and a non-metal which is hard.
State one property in which a solution of sugar in water resembles a mixture of sugar and sand, and one property in which it differs from it.
If 25 mL of acetone is present in 150 mL of its aqueous solution, calculate the concentration of solution.
Define solute.
A solid mixture contains four constituents P, Q, R and S. P consists of tiny grains and it is mixed with
cement for plastering the walls. Q is a white solid which is recovered on a large scale from sea water by the
process of evaporation. R is in the form of tiny particles of a material whose corrosion is called rusting. And
S is a white solid which is used in making ordinary dry cells.
- What could P, Q, R and S be ?
- How would you separate a mixture containing P, Q, R and S ?
The given mixture contains three constituents A, B and C. The constituent A is a yellow coloured, solid element which dissolves in a liquid D. The constituent B is a blue coloured salt which is insoluble in liquid D but dissolves easily in another liquid E. The constitudent C is a liquid which is used in cooking food and forms a solid fat on hydrogenation.
(a) What do you think could (i) constituent A, and (ii) liquid D be ?
(b) What could (i) constituent B, and (ii) liquid E be ?
(c) What could liquid C be ?
(d) How will you separate the mixture containing A, B and C ?
What's the solution?
We need to make a sherbet quickly for some guests. But we only have sugar candy in the house.
Asmita went to buy an earthen pot. There she saw many things kept for sale.
From what substance has the potter made all the things?
What type of matter glass is?
In Aerosol the dispersed phase is liquid and the dispersion medium is gas.
Liquids have ______.
Solids do not flow.
Write a scientific reason.
Lemon sherbat has a sweet, sour and salty taste and it can be poured in a glass.
Define the term matter.
Write a scientific reason.
Lemon sherbat has sweet, sour and salty taste and it can be poured in a glass.
Define the term matter.
