Question

What is the change in enthalpy in kilojoules when 2.30 mol of Mg is completely reacted according to the following reaction 2 Mg(s) + O2(g) – 2 MgO(S) AH = -1204 kJ STARTING AMOUNT ADD FACTOR ANSWER RESET () -0 o 0.001 2 -1204 1000 24.31 2770 -2770 2.30 2.30 6.022 * 10 32.00 32.00 -5540 -5540 40.31 40.31 -1380 -1380 1380 1380 5540 kJ gmg mol Mgg MgO gomol Mgo m olo:

Answer 1

The
H form
of the Mg and O2 is 0, because this's pure elements. However, the
H form
of the MgO is 601,83Kj/mol. The moles of the Mg reacted completely, so, this is the limited reactive. As a result:

lmolo2 2.30molMg = 2mol Mg -= 1,15molo2

2mol MgO 2.30molMg = 2mol Mg - = 2,30molo2

So, the is:

A form Mgo

AH form MgO = AH prod - AH react

AH form Mg0 = (2,30mol M XAHM9+1, 15molo21AH02)-(2, 30mol MgOr Delta HM90)

AH form MgO = -(2, 30mol.z601, 83kj/mol) = -1384, 21Kj