If 45.5 mL of 0.150 M sodium sulfate solution reacts completely with aqueous barium nitrate, what is the mass of BaSO4 (233.40 g/mol) precipitate? Ba(NO3)2(aq)+Na2SO4(aq)→BaSO4(s)+2NaNO3(aq)?
1 Answer
Oct 1, 2016
1.59g (3 s.f.)
Explanation:
In this reaction, every 1 mole of
- Calculate the moles of
Na2 SO4
n(Na2 SO4 ) = 0.0455L x0.150molL = 0.006825 mol
Notice that the L units cancel out, leaving only moles; this is basic conversion - Use the mole ratio of
Na2 SO4 toBaSO4 to find the moles ofBaSO4 . We established at the beginning that for every 1 mole ofNa2 SO4 that reacts, 1 mole ofBaSO4 is produced. This means that the number of moles ofNa2 SO4 that we have will be identical to the number of moles ofBaSO4 produced.
n(BaSO4 ) = n(Na2 SO4 ) = 0.006825 mol - Use the molar mass of
BaSO4 and the moles ofBaSO4 to calculate the mass ofBaSO4 produced
molar mass: 137.3 + 32.07 + 4(16) = 233.37g/mol
mass produced: 0.006825 mol x233.37gmol = 1.59g (3 s.f.)