Answer:
B I think I am pretty sure
The first one, "Production of hydronium ions."
if you have 1.27*10^-36= [Cu2+][X2-] then you can set both those values equal to x because they're stoichimetrically equal.
1.27*10^-36=x^2
Take the square root of both sides.
1.13*10^-18=x
That would be your solubility.
The first major contributor to the Sun's apparent motion is the fact that Earth orbits the Sun while tilted on its axis. The Earth's axial tilt of approximately 23.5° ensures that observers at different locations will see the Sun reach higher-or-lower positions above the horizon throughout the year.
hope this helps ^^
Boyle's law of ideal gas: This law states that the volume of a gas is inversely proportional to its pressure at a constant temperature. Acc to this law we can write the relation of pressure and volume as:

That means:

From that equation we can calculate Volume of gas at a certain pressure:
P₁=Initial pressure
V₁=Initial volume
P₂=Final pressure
V₂= Final volume
Here P₁, initial pressure is given as 85.0 kPa
V₁, initial volume is given as 525 mL
P₂, final pressure is 65.0 kPa

so,
V_{2}=85\times 525\div 65
=686 mL
Volume of gas will be 686 mL.