In order to calculate the mass of nitrogen, we must first calculate the mass percentage of nitrogen in potassium nitrate. This is:
% nitrogen = mass of nitrogen / mass of potassium nitrate
% nitrogen = 14 / 101.1 x 100
The mass of nitrogen = % nitrogen x sample mass
= (14 / 101.1) x 101.1
= 14 grams
The molar weight of nitrogen is 14. Each mole of urea contains two moles of nitrogen. Therefore, for there to be 14 grams of nitrogen, there must be 0.5 moles of urea.
Mass of urea = moles urea x molecular weight urea
Mass of urea = 0.5 x 66.06
Mass of urea = 33.03 grams
<span>If you look at the chlorine box, with the symbol Cl, you see the atomic mass is equal to 35.453 atomic mass units. This is the weighted average mass of chlorine, including its isotopes, as found in nature. This also means that one mole of chlorine atoms has a mass of 35.453 grams.</span>
Answer:
[2 ]Na+[2 ]H2O -> [ 2] NaOH + [1]H2
Answer:
19.91 J/K
Explanation:
The entropy is a measure of the randomness of the system, and it intends to increase in nature, thus for a spontaneous reaction ΔS > 0.
The entropy variation can be found by:
ΔS = ∑n*S° products - ∑n*S° reactants
Where n is the coefficient of the substance. The value of S° (standard molar entropy) can be found at a thermodynamic table.
S°, Cl(g) = 165.20 J/mol.K
S°, O3(g) = 238.93 J/mol.K
S°, O2(g) = 205.138 J/mol.K
So:
ΔS = (1*205.138 + 1*218.9) - (1*165.20 + 1*238.93)
ΔS = 19.91 J/K
