What volume (in ml ) of 0.200 m naoh do we need to titrate 40.00 ml of 0.140 m hbr to the equivalence point?

28 ml

Explanation:

At equivalence point the number of ions is equal the number of   ions and thus the acid has been completely neutralized by the base.

= molarity of acid

= volume of acid

= molarity of base

= volume of base

Thus 28 ml of 0.200 M NaOH are needed to titrate 40.00 mL of 0.140 M HBr to the equivalence point.

answer:

technetium is the most reactive. this is followed by silver. the least reactive out of these three elements is strontium.