THESE NOTES ARE PREPARED ACCORDING TO JKBOSE SYLLABI IN SIMPLIFIED AND CONCISE PATTERN
Q. Why sodium metal is kept in kerosene?
Ans: Sodium is highly reactive metal. It reacts with oxygen and water to produce Fire. To prevent this reaction it is kept in kerosene.
Q. Oxides of metals are basic in nature (T/F)
Ans: True
Q. Oxides of ..NON METALS... are acidic in nature.
Q. An acid is a substance which turns blue litmus ....RED......
Q. A base is a substance which turns red litmus ..BLUE...
Q. Name three uses of metals and three uses of non metals?
Ans: Metals are used in construction, jewellery, wires, heating elements etc.
Non metals are used as fuel, food, fertilizers etc.
Q. Name the metal present in chlorophyll and haemoglobin?
Ans: Chlorophyll contains Magnesium (Mg) and haemoglobin contains Iron (Fe).
Q. Which of the following can be easily beaten into thin sheets?
A. Zinc B. Phosphorus C. Sulphur D. Oxygen
Ans: A. Zinc
Q. Which of the following is correct?
A. All metals are ductile
B. All non metals are ductile
C. Generally, metals are ductile
D. Some non metals are ductile
Ans: C. Generally, metals are ductile
Q. Fill in the blanks.
A. Phosphorus is very REACTIVE non metal
B. Metals are conductors of heat and ELECTRICITY
C. Iron is .MORE... reactive than copper.
D. Metal react with acids to produce .HYDROGEN... gas.
Q. Mark "T" if the statement is true or "F" if it is false.
A. Generally non metals react with acids.
FALSE
B. Sodium is very reactive metal.
TRUE
C. Copper displaces zinc from zinc sulphate solution
FALSE
D. Coal can be drawn into wires.
FALSE.
Q. Some properties are listed in following table. Distingush between metals and non metals on the basis of these properties.
Ans:
Q. Give reasons for the following;
A. Aluminium foils are used to wrap food items.
Ans: Because Aluminium is malleable and does not react with food items.
B. Immersion rods for heating liquids are made of metallic substances.
Ans: Because metals are good conductor of heat and electricity.
C. Copper cannot displace zinc from its salt solution.
Ans: Because Zinc is more reactive than copper.
D. Sodium and pottasium are stored in kerosene.
Ans: Because they are highly reactive and catch fire when in contact with air and water.
Q. Can you store lemon pickles in aluminium utensils. Explain?
Ans: Lemon pickles are acidic and react with Aluminium to produce hydrogen gas. It spoils the pickles.
Hence, Lemon pickles cannot be stored in Aluminium utensils.
Q. Match the items in column I with those of column II.
Ans:
I. Gold : d. Jewellery
II. Iron : e. Machinary
III. Aluminium: c. Wrapping food
IV. Carbon: f. Fuel
V. Copper : b. Electric wires
VI. Mercury: a. Thermometers
Q. What will happen when:
A. Dilute sulphuric acid is poured on a copper plate?
Ans: Copper will not react with Dilute Sulphuric Acid.
Cu + H2SO4 ___> No Reaction
B. Iron nails are placed in copper sulphate solution?
Ans: The Iron displaces the Copper in Copper sulphate solution.
The colour of solution will change from blue to green.
Fe + CuSO4 ____> FeSO4 + Cu
Q. Sarish took a piece of burning charcoal and collected the gas evolved in test tube.
A. How will she find the nature of the gas?
Ans: Sarish shall bring a burning incense stick near the gas. It it burns, there is oxygen and If it stops burning, there is carbon dioxide.
B. Write down the word equations for all the reactions taking place in process.
Ans: Carbon + Oxygen __> Carbon Dioxide
Q. One day Reeta went to jewellers shop with her mother. Her mother gave old jewellery to the goldsmith to polish. Next day when they bought the jewellery back, they found that there was slight loss in the weight. Can you suggest a reason for the loss in weight?
Ans: The gold smith dips the Gold in Aqua regia which dissolves upper layer of jewellery.
Hence, there would have been slight loss in weight of Jewellery.
Q. Why phosphorus is stored in water?
Ans: Phosphorus is highly reactive non-metal. It reacts with oxygen to produce Fire. To prevent this reaction, it is kept in water.
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Quiz competition being held at H.S Amad.
