Application of Activity Series in the Preparation of Hydrogen

From the knowledge of activity series, name a metal which shows the following properties

It reacts readily with cold water

Thin strips of magnesium, copper, and iron are taken.

Arrange these metals in descending order of reactivity. 

Which metal is preferred for collecting hydrogen from:
Write the balanced equation

Steam

Metal in the powdered form reacts very slowly with boiling water, but it decomposes in steam. Name the metal.

Write a balanced equation for the reaction named metal with (i) boiling water (ii) steam.

When hydrogen is passed over a black solid compound A, the products are a 'colorless liquid' and a 'reddish-brown metal B'.

Substance B is divided into two parts each placed in separate test tubes.

Dilute HCl is added to one part of substance B and dilute HNO₃ to the other.

1. Name the substances A and B.
2. Give two tests for the colourless liquid formed in the experiment.
3. What happens to substance A when it reacts with hydrogen? Give reasons for your answer.
4. Write an equation for the reaction between hydrogen and substance A.
5. Is there any reaction between substance B and dilute hydrochloric acid? Give reasons for your answer.

A small piece of calcium metal is put into a small trough containing water. There is effervescence and white turbidity is formed.

What do you observe when a few drops of red litmus solution are added to the turbid solution.

From the knowledge of activity series, name a metal which shows the following properties:

It forms a base which is insoluble in water.