Answer:
Explanation:
Entropy change in the system : --
ΔG = −54 kJ⋅mol−1 (−13 kcal⋅mol−1) = −54 kJ⋅mol−1 (−13 x 4.2 kJ⋅mol−1)
= - 108.6 KJ / mol
ΔH = -251 kJ/mol (-60 kcal/mol) = -251 kJ/mol (-60 x 4.2 kJ/mol)
= - 503 KJ / mol
ΔG = ΔH - TΔS
ΔS = ( ΔH - ΔG ) / T
= - 503 + 108.6 / ( 273 + 25 ) KJ / mol k⁻¹
= - 1323.48 J / mol k⁻¹
Entropy change in the surrounding
+ 1323.48 J / mol k⁻¹
<em>Answer:</em>
The equlibrium concentration sof Ca+2 ion willl be 4.9×10∧-3 M
<em>Data Given:</em>
Ksp of CaSO4 = 2.4 × 10∧-5
CaSO4 ⇔ Ca+2 + SO4∧-2
<em>Solution:</em>
Ksp = [Ca+2].[ SO4∧-2]
2.4 × 10∧-5 = [x].[x]= x²
x = 4.9×10∧-3 M
<em>Result:</em>
- The conc. of Ca+2 ion is 4.9×10∧-3 M
Answer:
The value of the silver in the coin is 35.3 $
Explanation:
First of all, let's calculate the volume of the coin.
2π . r² . thickness = volume
r = diameter/2
r = 41 mm/2 = 20.5 mm
2 . π . (20.5 mm)² . 2.5 mm = 6601 mm³
Now, this is the volume of the coin, so we must find out how many grams are on it.
6601 mm³ / 1000 = 6.60 cm³
Let's apply density.
D = Mass / volume
10.5 g/cm³ = mass /6.60 cm³
10.5 g/cm³ . 6.60 cm³ = mass
69.3 g = mass
Each gram has a cost of 0.51$
69.3 g . 0.51$ = 35.3 $
Answer:
58.6 % by mass of Na₂CO₃
Explanation:
This is the reaction:
Na₂CO₃ + MgCO₃ + 4HCl → MgCl₂ + 2NaCl + 2CO₂ + 2H₂O
Let's find out the moles of CO₂ produced, by the Ideal Gases Law
1.24 atm . 1.67 L = n . 0.082 . 299K
(1.24 atm . 1.67 L / 0.082 . 299K) = n
0.0844 moles = n
Ratio is 2:1, so 2 moles of dioxide were produced by 1 mol of sodium carbonate. Let's make a rule of three:
2 moles of CO₂ were produced by 1 mol of Na₂CO₃
Then, 0.0844 moles of Co₂ would beeen produced by (0.0844 .1)/2 = 0.0422 moles of Na₂CO₃.
Let's convert this moles into mass (mol . molar mass)
0.0422 mol . 106 g/mol = 4.47 g
Finally we can know the mass percent of sodium carbonate in the mixture
(Mass of compound /Total mass) . 100 → (4.47 g / 7.63g) . 100 = 58.6 %