The butter of tin is represented by

The products formed when gaseous $HCl$ is passed into an aqueous $Na_2SO_3$ solution are:

Give reasons:
$(i)$ Conc. $HNO_3$ can be transported in aluminium container.
$(ii)$ $A$ mixture of dilute $NaOH$ and aluminium pieces is used to open drain.
$(iii)$ Graphite is used as lubricant.
$(iv)$ Diamond is used as an abrasive.
$(v)$ Aluminium alloys are used to make aircraft body.
$(vi)$ Aluminium utensils should not be kept in water overnight.
$(vii)$ Aluminium wire is used to make transmission cables.

If the starting material for the manufacture of silicones is $RSiCl_3$,write the structure of the product formed.

The presence of $Si$ in steel gives it

Polyphosphates are used as water softening agents because they .......