Answer:
1200g H20.
Step-by-step explanation:
Write out the balanced equation... when an organic compound is burned, like C2H2, it is burned in oxygen (O2) and produces Water and Carbon Dioxide (CO2)
so 2C2H2 + 5O2 = 2H2O + 4CO2
now that you have a balanced equation just convert to moles and solve
2000g C2H2 * 1mol C2H2 / 30gC2H2 * 2mol H2O/2mol C2H2 * 18gH2O/1molH20 = 1200g H20.