How much heat (in kilojoules) is evolved or absorbed in the reaction of 1.90g of Na with H2O ?

2Na(s) + 2H2O(l) - H2(g) deltH = -368.4kj.

I keep getting the wrong answer on this one.

Question

How much heat (in kilojoules) is evolved or absorbed in the reaction of 1.90g of Na with H2O ?

2Na(s) + 2H2O(l) -> H2(g) deltH = -368.4kj.

I keep getting the wrong answer on this one.

aaronq · Answer

Convert 1.9g of sodium to moles fo sodium

then divide by it's coefficient (2)

multiply by dH

anonymous · Answer

$$\frac{ 1.9 }{ 22.9898 } * -368.4 = -30.4465$$

I have entered -30.4 and had it counted wrong.

aaronq · Answer

you didn't take into account the stoichiometric coefficient into account.

you have to divide by 2

anonymous · Answer

Oh wow, sorry that is correct. Thanks!

aaronq · Answer

no problem