A chemist divides a 15.0 liter solution into two portions. The first portion has four times the volume of the second. Find the volume of the second portion. a. 12.0L
b. 4.OL
c. 6.0L
d. 3.0 L
e. 5.0L

Noble gases are the most reactive elements on the periodic table. a. true b. false

Nitric oxide (no) can be formed from nitrogen, hydrogen and oxygen in two steps. in the first step, nitrogen and hydrogen react to form ammonia: n2(g) + 2 h_2(g) rightarrow 2 nh_3 (g) delta h = -92. kj in the second step, ammonia and oxygen react to form nitric oxide and water: 4 nh_3(g) + 5 o_2(g) rightarrow 4no(g) + 6 h_2o(g) delta h = -905. kj calculate the net change in enthalpy for the formation of one mole of nitric oxide from nitrogen, hydrogen and oxygen from these reactions. round your answer to the nearest .

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