For them following reactions, the δh° rxn is not equal to δh°f for the product except for

a) 3mg(s)+n2(g)—> mg3n2(s)
b) 2ca(s)+o2(g)—> 2cao(s)
c)c2h2(g)+h2(g)—> c2h4(g)
d) 2c(graphite)+o2(g)—> 2co(g)
e) c(diamond)+o2(g)—> co2(g)

1. suppose a reaction mixture, when diluted with water, afforded 300 ml of an aqueous solution of 30 g of the reaction product malononitrile [ch2(cn)2], which is to be isolated by extraction with ether. the solubility of malononitrile in ether at room temperature is 20.0 g/100 ml, and in water is 13.3 g/100 ml. what weight of malononitrile would be recovered by extraction with (a) three 100-ml portions of ether and (b) one 300-ml portion of ether? suggestion: for each extraction, let x equal the weight extracted into the ether layer. in part (a), the concentration in the ether layer is x/100 and in the water layer is (30 x)/300; the ratio of these quantities is equal to k 20/13.3.

Compare the valence electron configuration of the nobles gas elements seen here. what statement is correct?

Consider the following reactions. (note: (s) = solid, (l) = liquid, and (g) = gas.) mg(s) + ½o2(g) → mgo(s) + 146 kcal/mole h2(g) + ½o2(g) → h2o(g), δh = -57.82 kcal/mole what type of reaction is represented by the previous two examples?