Answer: The volume of 0.684 mol of carbon dioxide at s.t.p. is 15.3 L
Explanation:
According to ideal gas equation:

P = pressure of gas = 1 atm (at STP)
V = Volume of gas = ?
n = number of moles = 0.684
R = gas constant = 
T =temperature =
(at STP)



Thus the volume of 0.684 mol of carbon dioxide at s.t.p. is 15.3 L
Answer:
a.One or more electrons will move to a higher energy orbit
Explanation:
Absorbing energy means that the electron gets excited and jumps to a higher level.
Moles of ammonium sulfate = 26.42/molar mass of (NH4)2SO4
= 26.42/132.14 = 0.19 mole.
Molarity = moles of ammonium sulfate/volume of solution
= 0.19/50x10^-3
= 3.8M
it's the last one because it's depended on the rock layers