Which of the following methods is used for the concentration of ore?

Which method is used to collect $H_2$ gas in a gas jar in the laboratory?

Account for the following:
$(a)$ Aluminium is more reactive than iron,but its corrosion is less than iron.
$(b)$ Hydrogen gas is not evolved when zinc metal reacts with dilute $HNO_3$.
$(c)$ Carbon is not used for reducing aluminium from aluminium oxide.

$A$ metal $E$ is stored under kerosene oil. When a small piece of it is left open in the air,it catches fire. When the product formed is dissolved in water,it turns red litmus blue.
$(i)$ Name the metal $E$.
$(ii)$ Write the chemical equations for the reaction when it is exposed to air and when the product is dissolved in water.
$(iii)$ Explain the process by which the metal is obtained from its molten chloride.

Which of the following oxides is neutral in nature?

Name one metal and one non-metal that are found in a liquid state at room temperature.