Answer:- 2.39 mL are required.
Solution:- It's a dilution problem and to solve this type of problems we use the dilution equation:

Where,
and
are molarities of concentrated and diluted solutions and
and
are their respective volumes.
= 1.10M
= 5.00mM = 0.005M (since, mM stands for milli molar and M stands for molar. 1M = 1000mM)
= ?
= 525 mL
Let's plug in the given values in the formula:



So, 2.39 mL of 1.10M are needed to make 525 mL of 5.00mM solution.
Answer: option D) energy was absorbed and entropy increased.
Explanation:
1) Given balanced equation:
2H₂O (l) + 571.6 kJ → 2 H₂ (g) + O₂(g).
2) Being the energy placed on the side of the reactants means that the energy is used (consumed or absorbed). This is an endothermic reaction.
So, the first part is that energy was absorbed.
3) As for the entropy, it is a measure of the disorder or radomness of the system.
Since, two molecules of liquid water were transformed into three molecules of gas, i.e. more molecules and more kinetic energy, therefore the new state has a greater degree of radomness, is more disordered, and you conclude that the entropy increased.
With that, you have shown that the right option is D) energy was absorbed and increased.
The Molar mass of 50g of water is (18.015 g/mol). Hope this helps