B I think is right. Hope this helps!
Answer:
n = 0.573mol
Explanation:
PV = nRT => n = PV/RT
P = 1.5atm
V = 8.56L
R = 0.08206Latm/molK
T = 0°C = 273K
n = (1.5atm)(8.56L)/(0.08206Latm/molK)(273K) = 0.573mol
A) in pure water :
by using ICE table:
According to the reaction equation:
BaCrO4(s) → Ba^2+(aq) + CrO4^2-(aq)
initial 0 0
change +X +X
Equ X X
when Ksp = [Ba^2+][CrO4^2-]
by substitution:
2.1 x 10^-10 = X* X
∴X = √2.1 x 10*-10
∴X = 1.4 x 10^-5
∴ the solubility = X = 1.4 X 10^-5
B) In 1.6 x 10^-3 m Na2CrO4
by using ICE table:
According to the reaction equation:
BaCrO4(s) → Ba^2+(aq) + CrO4^2-(aq)
initial 0 0.0016
Change +X +X
Equ X X+0.0016
when Ksp = [Ba^2+][CrO4^2-]
by substitution:
2.1 x 10^-10 = X*(X+0.0016) by solving for X
∴ X = 1.3 x 10^-7
∴ solubility =X = 1.3 x 10^-7
This is a biology question. Cyanobacteria partake in photsynthesis, meaning they take in carbon dioxide and water to produce glucose and oxygen.