Question

Balance and classify the following reaction
Ba(OH)2(aq) + H2SO4(aq) →BaSO4 (s) +H2O(l)

Answer 1

You have to put coefficient 2 at the water formula:

$Ba(OH)_2(aq)+H_2SO_4(aq) \rightarrow BaSO_4(s)+2H_2O(l)$

It is double displacement reaction (AB + CD = AD + BC).