Help quick pls

What is the formula for the compound dinitrogen pentoxide? a. n4o5 b. n5o4 c. n4o6 d. n5o2 e. n2o5

In the reaction between a crushed antacid tablet and vinegar what gas is emitted

If you add 5.00 ml of 0.100 m sodium hydroxide to 50.0 ml of acetate buffer that is 0.100 m in both acetic acid and sodium acetate, what is the ph of the resulting solution? acetic acid: ka = 1.8. x 10-5