Answer:
Li 2SO4(aq) + Ba(NO3)2(aq) .
Explanation:
Given that
Li 2SO4(aq) + Ba(NO3)2(aq)
NaNO3(aq) + NH4Cl(aq)
CsI(aq) + NaOH(aq)
HCl(aq) + Ca(OH)2(aq)
From the above given reaction ,the reaction between Li 2SO4(aq) + Ba(NO3)2(aq) will result in a precipitation reaction and BaSO4 will be precipitate.
So the answer is Li 2SO4(aq) + Ba(NO3)2(aq) .