Which of the following could be added to a solution of sodium acetate to produce a buffer a) acetic acid only b) acetic acid or hydrochloric acid c) hydrochloric acid only d) potassium acetate only e) sodium chloride or potassium acetate

Can someone me with 1 to 4 plz. fast

Which best describes the present-day universe? opaque, expanding very slowly, stars produce heavy elements transparent, expanding at an accelerated rate, stars produce heavy elements opaque, expanding at an accelerated rate, stars produce only hydrogen and helium transparent, expanding very slowly, stars produce only hydrogen and helium

Occluded fronts happen when warm air mass can get caught between two cold air fronts which can force the warm air up into a wedge shape true or false