It might be the fourth one? Sorry, it’s been a while since I’ve done something like this.
Answer:
X2Z3
Explanation:
Based on the clues, X is a metal and Z is a non-metal.
X could be aluminum and Z would need to be an element from the oxygen family.
Answer: 66.66 ml
Explanation: Using Molarity equation:
(stock solution)=
(solution to be prepared)
given: 



(stock solution)=
(solution)
