Which of the following statement is not correct?
A furnace lined with haematite is used to convert cast iron to wrought iron
Collectors enhance the muttability of mineral particles during froth floatation
In vapour phase retining metal should form a volatile compound
Copper from its low grades ores is extracted by hydrometallurgy
A storage battery contains a solution of H2SO4 38% by weight. At this concentration, the van't Hoff factor is 2.50. At what temperature will the battery contents freeze? (Kf =1.80 mol' kg)
243.92 K
298 K
240.92 K
273 K
which of the following reactions of glucose can be explained only by its cyclic structure?
Glucose forms penta acetate.
Glucose reacts with hydroxyl amine to form an oxime.
Penta acetate of glucose does not react with hydroxylamine.
Glucose is oxidised by nitirc acid to gluconic acid.
C.
Penta acetate of glucose does not react with hydroxylamine.
"Penta acetate of glucose does not react with hydroxylamine,''showing absence of free CHO group.This cannot be explained by open structure of glucose. While all other properties are easily explained by open chain structure of glucose.
Aldehydes or ketones are treated with-bromo ester in the presence of zinc to form -hydroxy ester followed by dehydration to form ,-unsaturated ester.This reaction is known as:
Witting reaction.
Tischenko reaction.
Reformatsky reaction.
Crossed-cannazzaro's reaction.
Which among the following alcohols is most reactive with sodium wire?
Ethanol
2-Propanol
2-Butanol
2-Methyl-2-butanol
The theory of enzyme mechanism that suggests a rigid, in flexible molecules is:
coenzyme model.
induced-fit model.
lock and key model.
substrate specific model.
The correct structure of the stable compound which is obtained when acetophenone react with a base C2H5OH is
Which of the following organic halogen compounds undergoes hydrolysis with aqueous NaOH predominantly by Sy1 mechanism?
Ethyl iodide
Methyl chloride
lsopropyl chloride
Benzyl chloride
The night blindness and pernicious anaemia are causes due to deficiency of:
Vitamin B6 and vitamin B12, respectively
Vitamin A and vitamin B12 respectively
Vitamin C and vitamin K, respectively
Vitamin B2 and vitamin B12 respectively