Answer:
34,6g of (NH₄)₂SO₄
Explanation:
The boiling-point elevation describes the phenomenon in which the boiling point of a liquid increases with the addition of a compound. The formula is:
ΔT = kb×m
Where ΔT is Tsolution - T solvent; kb is ebullioscopic constant and m is molality of ions in solution.
For the problem:
ΔT = 109,7°C-108,3°C = 1,4°C
kb = 1.07 °C kg/mol
Solving:
m = 1,31 mol/kg
As mass of X = 600g = 0,600kg:
1,31mol/kg×0,600kg = 0,785 moles of ions. As (NH₄)₂SO₄ has three ions:
0,785 moles of ions×
= 0,262 moles of (NH₄)₂SO₄
As molar mass of (NH₄)₂SO₄ is 132,14g/mol:
0,262 moles of (NH₄)₂SO₄×
= <em>34,6g of (NH₄)₂SO₄</em>
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I hope it helps!
Answer:
there are four peaks in the 13c NMR (B)
When in water, MgCl2 dissociates into magnesium ions and Cl- ions and NaOH into Na and OH ions. The equation is as follows:
MgCl2 = Mg2+ + 2Cl-
NaOH = Na+ + OH-
The initial concentrations are as follows:
[Mg2+] = .220(<span> 2.47x10^-4) / .220+.180 = 1.36x10^-4 M Mg2+
</span>[OH-] = .180 (3.52x10^-4) / .220+.180 = 1.58x10^-4 M OH-
Answer:
Theoretical yield = 2.5 g
Explanation:
Given data:
Mass of sodium = 79.7 g
Mass of water = 45.3 g
Theoretical yield of hydrogen gas = ?
Solution:
Chemical equation:
2Na + 2H₂O → 2NaOH + H₂
Number of moles of sodium:
Number of moles = mass/ molar mass
Number of moles = 79.7 g / 23 g/mol
Number of moles = 3.5 mol
Number of moles of water:
Number of moles = mass/ molar mass
Number of moles = 45.3 g / 18g/mol
Number of moles = 2.5 mol
Now we will compare the moles of hydrogen gas with water and sodium.
H₂O : H₂
2 : 1
2.5 : 1/2×2.5 =1.25 mol
Na : H₂
2 : 1
3.5 : 1/2×3.5 =1.75 mol
water will be limiting reactant.
Theoretical yield:
Mass = number of moles × molar mass
Mass = 1.25 mol × 2 g/mol
Mass = 2.5 g
