The answer to your question is B.
Answer: There are 78.26 mL of a 0.0023M strontium hydroxide solution are needed to completely react 15.0 mL of 0.012M hydrochloric acid.
Explanation:
Given:
= 0.0023 M,
= ?
= 15.0 mL,
= 0.012 M
Formula used to calculate volume of strontium hydroxide solution is as follows.

Substitute the values into above formula as follows.

Thus, we can conclude that there are 78.26 mL of a 0.0023M strontium hydroxide solution are needed to completely react 15.0 mL of 0.012M hydrochloric acid.
Answer:
119.85 grams Br or 120. grams Br (sig figs)
Explanation:
1.50 moles Br 79.90 g Br
--------------------- x ------------------------ = 119.85 grams Br or 120 grams Br (sig figs)
1 mole
Solid , solid, partially melted, liquid so the answer is D