State one industrial application of the reduction process.

If copper metal is heated over a flame, it develops a coating. What is the colour and composition of this coating?

When a green iron salt is heated strongly, its colour finally changes to black and the odour of burning sulphur is given out.
$(a)$ Name the iron salt.
$(b)$ Name the type of reaction that takes place during the heating of iron salt.

$A$ dilute ferrous sulphate solution was gradually added to the beaker containing acidified permanganate solution. The light purple colour of the solution fades and finally disappears. Which of the following is the correct explanation for the observation?

Write true or false for the following statement:
During endothermic reactions,heat is transferred from the reacting substances to the surroundings.

Why do we store silver chloride in dark-coloured bottles?