Home › CBSE Class 8 › chemistry › combustionandflame › Goldsmiths blow the OUTERMOST zone of a flame th…
Goldsmiths blow the OUTERMOST zone of a flame through a metallic blowpipe when melting gold or silver because:
AIt is the hottest zone and provides the highest temperature for melting
BIt is the coolest zone and won't damage the metal
CIt is the brightest zone, making it easier to see
DIt contains the most unburnt fuel
Answer & Solution
Correct answer: A. It is the hottest zone and provides the highest temperature for melting
Complete combustion takes place in the outermost (non-luminous) zone — it is the hottest. The metal needs the highest possible temperature to reach its melting point, so the goldsmith directs this zone onto the metal using a blowpipe.
Related questions
Forest fires can sometimes start without any human cause. Two natural mechanisms mentionedA 'good' or 'ideal' fuel should have ALL of the following properties EXCEPT:Carbon monoxide (CO) is particularly dangerous because:Why is wood being progressively replaced by LPG in many Indian households?Sulphur and nitrogen in fuels are particularly harmful because, when burned, they form sulIf LPG has a calorific value of ~55 kJ/g and wood has a calorific value of ~20 kJ/g, then Three conditions are essential for fire: fuel, oxygen and ignition temperature (the 'fire Among solid, liquid and gaseous fuels — which is the EASIEST to control flame size and tur