4. (a) what weight of glycine (pka1 = 2.4; pk2 = 9.6), and what volume of im hcl are required to make 100 ml. of 0.3m buffer, ph 2.4? (b) what weight of glycine and what volume of 1m naoh are required to make 100 ml of 0.3m buffer, ph 9.3? remember that glycine is sold as the zwitterion salt.

For which one of the following reactions is the value of δh° rxn equal to δh° f for the product? a. 2 h2 (g) + o2 (g) → 2 h2o (l) b. n2 (g) + o2 (g) → 2 no (g) c. 2 h2 (g) + o2 (g) → 2 h2o (g) d. h2o (l) + 1/2 o2 (g) → h2o2 (l) e. none of the above

What is the number of moles in 15.0 g ash3?

Which statement correctly describes metallic bonds? a. they form when certain atoms lose electrons and other atoms gain electrons. b. they involve an attraction between anions and cations. they always involvpoth a metal and a nonmetal. d. they can only form between atoms of the same element. e. they form because electrons can move freely between atoms.