Give reasons a) Coal and petroleum …

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Give reasons a) Coal and petroleum are fossil fuels b)Aluminium foils are used to wrap food items c)Sodium and potassium are stored in kerosene d)Cu cannot displace Zinc from its salt solution

Posted by Nikku Nagawade 5 years, 11 months ago

CBSE > Class 08 > Science

3 answers

Abhay Dev 5 years, 11 months ago

A) Exhaustible natural resources like coal, petroleum and natural gas are formed from the dead remains of living organisms (fossils). So, these are all known as fossil fuels. B) Aluminum foils are used to wrap food items because aluminum metal is malleable. Therefore, it can be beaten into thin foils. C) Sodium and potassium are stored in kerosene because they are highly reactive elements. They can easily catch fire even when in contact with air. D) A metal can displace a less reactive metal from its salt in an aqueous solution. But zinc is more reactive than copper. Therefore, copper cannot displace zinc from its salt solution. Cu(s) +ZnSO4(aq) ➡️No reaction

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Nikku Nagawade 5 years, 11 months ago

Thanks

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Patel Arvind Bhai 5 years, 11 months ago

(b) Aluminium is malleable, soft and does not react with food items, so it is used to wrap food items (c) sodium and potassium are very reactive metals. They react with air and water but cannot react with kerosene. Both metals are heavier than kerosene so they sink in kerosene. So, sodium and potassium are stored in kerosene (d ) Copper is less reactive than zinc., So, it cannot displace zinc from its salt solution

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