Hi :) how to do 4(b)?

Calculate the mass percent of hydrogen in methyl acetate

You encounter a solution that is acidic and you decide to test it by adding a small amount of a strong acid. the ph lowers slightly but is approximately unchanged, and still remains acidic. what can you say about the solution? a. it is a buffer solution. b. it is not a buffer solution it is a strong acid solution. d. the solution has been neutralized. e. the solution has excess acid present

Which of the following would be an accurate picture of the earth during the summer time of the northern hemisphere?