Lithium hydrogen carbonate, lihco3, decomposes when heated to form li2o, co2, and h2o. how many moles of h2o are formed when 0.50 mol lihco3 decomposes?

0.25 mol of water

Explanation:

The starting point is writing out a balanced chemical equation

From here we can see that 2 moles of Lithium hydrogen carbonate produce 1 mole of water. It follows that 0.5 moles of Lithium hydrogen carbonate will produce half of that too, which is 0.25 moles. The ratio is always mantained.