Answer:
1. Na2SO4(aq)+C4H6BaO4(aq) --> BaSO4(s) + 2C2H3NaO2(aq)
2. 2Na^+1(aq) + SO4^-2(aq) + 4C^+4(aq) + 6H^+1(aq) + Ba^-2(aq) + 4O^-2(aq) --> BaSO4(s) + 2C^-4(aq) + 2H^+1(aq) + 3Na^+1(aq) + 2O^-2(aq)
3. Ba^+2(aq) + SO4^-2(aq) --> BaSO4(s)
Explanation:
Answer:The correct answer option A.
Explanation:

Q= heat removed from the water
m= mass of the water = 80 grams
c = heat capacity of water= 4.18 J/g°C

Q = -10,032 joules
-10,000 Joules
Negative sign indicates that heat was removed from the water.
Heat removed from the water of 80 gram of water is 10,032 Joules.Hence, the correct answer option A.