Write the names of the following compounds:
$(a)$ $NiS$
$(b)$ $Mg(NO_3)_2$
$(c)$ $Na_2SO_4$
$(d)$ $Al(NO_3)_3$
$(e)$ $K_3PO_4$
$(f)$ $Ca_3N_2$

Which of the following statements is not true about an atom?

Write the chemical formulae and names of the compounds formed by the combination of:
$(i)$ $Fe^{3+}$ and $SO_{4}^{2-}$
$(ii)$ $NH_{4}^{+}$ and $CO_{3}^{2-}$

You are provided with a fine white-coloured powder which is either sugar or salt. How would you identify it without tasting?

Write the chemical formulae for the following substances and calculate the molecular mass for each one of them:
$(a)$ Caustic potash
$(b)$ Baking soda
$(c)$ Limestone
$(d)$ Caustic soda
$(e)$ Ethanol
$(f)$ Common salt

Calculate the number of moles in $5.75 \, g$ of sodium (atomic mass of sodium $= 23$).