Name the precipitate formed when an aqueous solution of sodium sulphate and barium chloride are mixed.

The reacting species are sodium sulfate (Na2SO4) and barium chloride (BaCl2) and the chemical reaction between these species can be written as:

`Na_2SO_4 (aq) + BaCl_2 (aq) -> BaSO_4 (s) + NaCl (aq)`

In this reaction, sodium sulfate reacts with barium chloride, both in aqueous phase, to produce barium sulfate and sodium chloride. 

The above mentioned equation is not balanced, for example, in terms of sodium (1 versus 2 atoms on reactant and product sides). The well-balanced chemical equation for this reaction is:

`Na_2SO_4 (aq) + BaCl_2 (aq) -> BaSO_4 (s) + 2 NaCl (aq)`

Here, the only solid is barium sulfate and hence this is the required precipitate of this reaction. 

We can also use this reaction to determine the amount of the precipitate formed when certain amounts of the reactants are used. Using the stoichiometry, 1 mole of sodium sulfate reacts with 1 mole of barium chloride to form 1 mole of barium sulfate precipitate and 2 moles of sodium chloride.

Hope this helps.