61. If a 1.0 M solution of HA, a weak acid, has a pH of 2.0, then the value of Ka, the acid-dissociation constant, for HA is closest to A. 1.0 × 10-4 B. 1.4 × 10-4 C. 1.0 × 10-2 D. 1.4 × 10-2 E. 1.4 × 10-1

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)

Light waves are as they pass through the

Which process describes vaporization that takes place below the surface of a liquid? condensation melting boiling evaporation