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
Wolframite ore is separated from tin stone ore by the process of
roasting
electromagnetic
smelting
calcination
B.
electromagnetic
Wolframite ore (FeWO4) is present in tin stone in the form of impurities and same mass per unit as tin stone. It is magnetic in nature and tin stone is non-magnetic in nature. They are separated by magnetic separation. It is attracted by magnet and falls just below magnet while tin stone falls away from it.
Roasting and calcination method for conversion of ore into made.
Smelting is used for iron.
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