# Chemistry

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Given:
H3PO4(aq) + 3 NaOH(aq) ¨ 3 H2O(l) + Na3PO4(aq)
ƒ¢H = -166.5 kJ

What is the value for q (heat) if 4.00 g of NaOH reacts with an excess of H3PO4?

Please can you explain to me HOW to do this, not just give me an answer?
Thanks!

• Chemistry -

The heat of reaction has the wrong units...it should be -166.5kJ/MoleNa3PO4

So, the question is, the reaction calls for three moles (120g) of NaOH, so you will get 4/120 fraction of the heat of reaction.

• Chemistry -

Given:
H3PO4(aq) + 3 NaOH(aq) yields 3 H2O(l) + Na3PO4(aq)
change in H = -166.5 kJ

What is the value for q (heat) if 4.00 g of NaOH reacts with an excess of H3PO4?

Please can you explain to me HOW to do this, not just give me an answer?
Thanks!

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