The reversible of nature of crystasllizing & dissolving
4X + 3O₂ = 2X₂O₃
n(X₂O₃)=0.02225 mol
m(X)=4.000 g
x - the molar mass of metal
m(X)/4x=n(X₂O₃)/2
x=m(X)/{2n(X₂O₃)}
x=4.000/{2*0.02225)=89.89 g/mol
X=Y (yttrium)
It would be letter C, because the molecules of solids can have a little vibration in their places.
The first one is for gas, so it's wrong. The second one is for liquids. And finally, the third one is right.
Centi- (symbol c) is a unit prefix in the metric system denoting a factor of one hundredth.
The Arrhenius equation relates activation energy to reaction rates and temperature:
ln (k2 / k1) = (E / R) * (1/T1 - 1/T2), where E is activation energy of 272 kJ, R is the ideal gas constant (we use the units of 0.0083145 kJ/mol-K for consistency, to cancel out the kJ unit), we let T1 = 718 K and k1 = 2.30 x 10^-5, and T2 = 753 K and k2 be the unknown.
ln (k2 / 2.30x10^-5) = (272 kJ / 0.0083145 kJ/mol-K) * (1/718 - 1/753)
k2 = 1.91 x 10^-4 /s
