Question

Many grams of `H_3PO_4` are produced when 12.0 moles of water react with an excess of `P_4O_10`? `P_4O_10(s) + 6H_2O(l) -> 4H_3PO_4(aq)`?

Answer 1

You have the stoichiometric equation..........

Explanation:

And, by the stoichiometry, if `"12 mole"` of water react, then `"8 mole"` of `"phosphoric acid"` will result, and this constitutes a mass of.............

`12*molxx97.99*g*mol^-1~=1200*g`

When you use `P_4O_10` in the lab (and it is often used as a dessicant), usually when you take the lid off a pre-used jar, you will often notice a syrupy crust of phosphoric acid on top of the powder. You have to dig down beneath this crust to get to the free-flowing powder.

Of what do you think the syrupy crust is composed?