I'm certain it's "D"
...because it can't be "A" or "B" because solubility IS a property but to actually determine whether these two substances are the same or different we would need at least two-three properties (like boiling point or specific heat).
and it can't be "C" because the melting point is just simply irrelevant when comparing the solubility of two substances.
Answer:
1.73 atm
Explanation:
Given data:
Initial volume of helium = 5.00 L
Final volume of helium = 12.0 L
Final pressure = 0.720 atm
Initial pressure = ?
Solution:
"The volume of given amount of gas is inversely proportional to its pressure by keeping the temperature and number of moles constant"
Mathematical expression:
P₁V₁ = P₂V₂
P₁ = Initial pressure
V₁ = initial volume
P₂ = final pressure
V₂ = final volume
Now we will put the values in formula,
P₁V₁ = P₂V₂
P₁ × 5.00 L = 0.720 atm × 12.0 L
P₁ = 8.64 atm. L/5 L
P₁ = 1.73 atm
H:O = 4:5;
(UO₂)₂ = 4 O atoms;
(PO₄)₂ = 8 O atoms:
8H₂O = 16 H atoms + 8 O atoms;
Total = 16 H atoms + 20 O atoms;
H:O = 16:20 = 4:5