Please help me!! A sample of oxygen gas(O₂) has a mass of 29.0 grams at STP, what volume will it occupy?

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 position represents spring in the southern hemisphere? a) b) c) d)

Compare and contrast physical changes with chemical changes.