Excess of KI reacts with CuSO4 solution and then Na2S2O3 solution is added to it. Which of the statements is incorrect for this reaction ?
Cu2I2 is formed
CuI2 is formed
Na2S2O3 is oxidised
Evolved I2 is reduced
The process of zinc-plating on iron sheet is known as:
annealing
roasting
galvanization
smelting
The method of zone refining of metals is based on the principle of
greater noble character of the solid metal than that of the impurity
greater solubility of the impurity in the molten state than in the solid
greater mobility of the pure metal than that of impurity
higher melting point of the impurity than that of the pure metal
Mixtur e of MgCl2, and MgO is called :
Portland cement
Sorrel's cement
double salt
none of these
Therrnite process is used in reduction of
Cr2O3
Al2O3
PbO2
CuO
A.
Cr2O3
Thermite process is used for the reduction of oxides of less electropositive metals. Oxides of less electropositive metals such as Cr2O3, Mn3O4 etc are reduced by using Al. This process is called thermite process.
Cr2O3 + 2Al → Al2O3 + 2Cr + Heat
Wolframite ore is separated from tin stone ore by the process of
roasting
electromagnetic
smelting
calcination
In the extraction of copper, metal is formed is the Bessemer converter due to reaction
2Cu2S + 2Cu2O → 6Cu + SO2
2Cu2O → 4Cu + O2
Cu2S → 2Cu + S
Fe + Cu2O → 2Cu + FeO
Which of the following is an alum?
Na·AlO2
Na2SO4·Al2(SO4)3·24H2O
KCl·MgCl2·6H2O
FeSO4 ·(NH4)2SO4·6H2O