Advertisements
Advertisements
Write true or false
All pure substances have characteristic melting and boiling points.
Concept: undefined >> undefined
Match the columns.
| Column A | Column B |
| 1. To separate grain from chaff | a. filtration |
| 2. To seperat sawdust from water | b. sedimentation and decantation |
| 3. To separate iodine from sodium chloried | c. winnowing |
| 4. To separate iron fillings from sand | d. sublimation |
| 5.It is used to separate sand and water | e.magnetic separation |
| f. handpiicking |
Concept: undefined >> undefined
Advertisements
Differentiate between the following.
solution and suspension
Concept: undefined >> undefined
How can you separate iron metal from non-magnetic impurities ?
Concept: undefined >> undefined
Name the substance you will add to speed up sedimentation.
Concept: undefined >> undefined
Why is filtration a better technique than sedimentation and decantation ?
Concept: undefined >> undefined
What is centrifugation ? Also write the principle on which it works.
Concept: undefined >> undefined
Define chemical reaction.
Concept: undefined >> undefined
State four conditions necessary for chemical reactions to take place.
Concept: undefined >> undefined
Differentiate between in Chemical reaction and chemical equation.
Concept: undefined >> undefined
Fill in the blank:
The substances which undergo chemical change are called _______
Concept: undefined >> undefined
Fill in the blank:
The substances formed as a result of a chemical reaction are called _______
Concept: undefined >> undefined
Fill in the blank:
During a chemical reaction transfer of ________ takes place.
Concept: undefined >> undefined
Fill in the blank:
The basic conditions necessary for a chemical reaction is _______
Concept: undefined >> undefined
Fill in the blank:
In some chemical reactions an insoluble ________ is formed when two solutions are mixed.
Concept: undefined >> undefined
Write true or false :
No new substance is formed during a chemical reaction.
Concept: undefined >> undefined
Write true or false :
Hydrogen sulphide has rotten egg smell .
Concept: undefined >> undefined
Write true or false :
When potassium iodide solution is added to lead acetate solution a red precipitate is formed.
Concept: undefined >> undefined
Write true or false .
A black residue is formed when sugar is heated .
Concept: undefined >> undefined
Write true or false :
When iron and sulphur are heated together a grey mass is formed which is attracted by a magnet .
Concept: undefined >> undefined
