Ab c or d ? i’m not sure what the answer is

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 .

How many atoms of mg are present in 97.22 grams of mg? 6.022 × 1023 2.408 × 1024 4.818 × 1024 5.855 × 1025

If 4.8 moles of x and 3.4 moles of y react according to the reaction below, how many moles of the excess reactant will be left over at the end of the reaction? 3x + 2y “yields”/ x3y2. a. 1.7 mol y left over b. 1.6 mol x left over c. 0.2 mol y left over d. 0.1 mol x left over