The suitable reaction for concentrating ore by leaching process is:
\(Al _2 O _3+2 NaOH +3 H _2 O \rightarrow 2 Na \left[ Al ( OH )_4\right]\)
This is because the reaction involves the conversion of the metal oxide (in this case, aluminum oxide) into a water-soluble form (sodium aluminate), which can be easily separated from the impurities in the ore through leaching. Leaching involves dissolving the desired metal compound using a suitable solvent, in this case, sodium hydroxide solution. This process allows for the concentration of the ore by selectively dissolving the desired metal compound while leaving behind the impurities.
So, the correct option is (C).
A parallel plate capacitor with plate area \(A\) and plate separation \(d = 2\) m has a capacitance of \(4\mu F\). The new capacitance of the system if half of the space between them is filled with a dielectric material of dielectric constant \(K = 3\) (as shown in the figure) will be:
A block of mass 1 kg is pushed up a surface inclined to horizontal at an angle of \( 60^\circ \) by a force of 10 N parallel to the inclined surface. When the block is pushed up by 10 m along the inclined surface, the work done against frictional force is:
[Given: \( g = 10 \) m/s\( ^2 \), \( \mu_s = 0.1 \)]
Minerals are the naturally occurring, homogeneous inorganic solid substances. They are having a definite chemical composition and crystalline structure, hardness and color. For example, copper pyrite, calamine, etc.
Impurities in an ore are called gauge. The removal of a gauge from the ore is called concentration ore.
Several steps are involved in the extraction of pure metal from ores. Major steps are as follows –