One liter of a solution contains 0.120 moles of benzoic acid c6h5cooh (ka = 6.5 x 10-5) and 0.105 moles of sodium benzoate c6h5coona. a) calculate the ph of this solution. b) calculate the ph of the resulting solution after adding 100 ml of 1.20 m solution of naoh to the starting solution; c) calculate the ph of the resulting solution after adding 100 ml of 0.100 m hcl solution to the starting solution.

Noble gases are the most reactive elements on the periodic table. a. true b. false

Look at the spectrums of a star moving towards earth and a motionless star. which of these is a correct inference that can be draw from the observation of the two spectrums? (2 points) the spectrum of a motionless star is difficult to be viewed separately using oridinary telescopes. the spectrum of a motionless star is identical to the spectrum of a star which moves towards earth. the spectrum of a star shifts towards the red region when the star moves towards earth. the spectrum of a star shifts towards the blue region when the star moves towards earth.

How does a sample of helium at 15 degree celsius compare to a sample of helium at 215 k? a) the helium at 15 degrees celsius has a higher average kinetic energy that the sample at 215 k. b) the helium at 15 degrees celsius has lower nuclear energy that the sample at 215 k. c) the helium at 15 degrees celsius has slower- moving atoms that the sample at 215 k. d) the helium at 15 degrees celsius has smaller atoms than the sample at 215 k.