Calculate the volume (in mL) of NO2 at 1 atm and 273 K obtained by treating 12.7 g of Cu with an excess of concentrated nitric acid from the following reaction: Cu(s) + HNO3(aq) —• Cu(NO3)2(aq) + H200(l) + NO2

1). 8960 2 ). 896

3 ). 89.3 4). 6900

Given the following at 25c calculate delta hf for hcn (g) at 25c. 2nh3 (g) +3o2 (g) + 2ch4 (g) > 2hcn (g) + 6h2o (g) delta h rxn= -870.8 kj. delta hf=-80.3 kj/mol for nh3 (g), -74.6 kj/mol for ch4, and -241.8 kj/mol for h2o (g)

Afusion reaction takes place between carbon and another element. neutrons are released, and a different element is formed. the different element is a) lighter than helium.b)heavier than helium.c)the same weight as helium.d)dependent on the element that reacted with carbon.

1.17 mol hcl and 2.5 mol naoh react according to the equation hcl + naoh -> nacl + h2o . if the limiting reactant is hcl, determine the amount of excess reactant that remains. answer in units of mol.