Given the molar mass of Nitrogen is 14.01g/mol you can use that to solve for the moles of nitrogen.
0.235g(1mol/14.01g) = .0168 moles.
Answer:
(a) ΔSº = 216.10 J/K
(b) ΔSº = - 56.4 J/K
(c) ΔSº = 273.8 J/K
Explanation:
We know the standard entropy change for a given reaction is given by the sum of the entropies of the products minus the entropies of reactants.
First we need to find in an appropiate reference table the standard molar entropies entropies, and then do the calculations.
(a) C2H5OH(l) + 3 O2(g) ⇒ 2 CO2(g) + 3 H2O(g)
Sº 159.9 205.2 213.8 188.8
(J/Kmol)
ΔSº = [ 2(213.8) + 3(188.8) ] - [ 159.9 + 3(205.) ] J/K
ΔSº = 216.10 J/K
(b) CS2(l) + 3 O2(g) ⇒ CO2(g) + 2 SO2(g)
Sº 151.0 205.2 213.8 248.2
(J/Kmol)
ΔSº = [ 213.8 + 2(248.2) ] - [ 151.0 + 3(205.2) ] J/K = - 56.4 J/K
(c) 2 C6H6(l) + 15 O2(g) 12 CO2(g) + 6 H2O(g)
Sº 173.3 205.2 213.8 188.8
(J/Kmol)
ΔSº = [ 12(213.8) + 6(188.8) ] - [ 2(173.3) + 15( 205.2) ] = 273.8 J/K
Whenever possible we should always verify if our answer makes sense. Note that the signs for the entropy change agree with the change in mol gas. For example in reaction (b) we are going from 4 total mol gas reactants to 3, so the entropy change will be negative.
Note we need to multiply the entropies of each substance by its coefficient in the balanced chemical equation.
Answer is either B or all of the above. “G” is not an element on the periodic table. If it’s not a typo, then the answer is B.
The mass of NiCl₂•6HO₂ needed to prepare a 0.035 M 500 mL solution of NiCl₂•6HO₂ is 4.165 g
<h3>What is molarity? </h3>
This is defined as the mole of solute per unit litre of solution. Mathematically, it can be expressed as:
Molarity = mole / Volume
<h3>How to determine the mole of NiCl₂•6HO₂</h3>
- Molarity = 0.035 M
- Volume = 500 mL = 500 / 1000 = 0.5 L
Mole = Molarity × Volume
Mole of NiCl₂•6HO₂ = 0.035 × 0.5
Mole of NiCl₂•6HO₂ = 0.0175 mole
<h3>How to determine the mass of NiCl₂•6HO₂</h3>
- Mole of NiCl₂•6HO₂ = 0.0175 mole
- Molar mass of NiCl₂•6HO₂ = 238 g/mol
Mass = mole × molar mass
Mass of NiCl₂•6HO₂ = 0.0175 × 238
Mass of NiCl₂•6HO₂ = 4.165 g
Thus, 4.165 g of NiCl₂•6HO₂ is needed to prepare the solution
Learn more about molarity:
brainly.com/question/15370276
