Answer:
N₂ gas at 50 °C.
Explanation:
- From the postulates of the kinetic theory of gases; <em>all gases at a given temperature have the same average kinetic energy</em>.
- The average kinetic energy of gases can be calculated from the relation: K =
T.
Where, K is the average kinetic energy (measured in Joule),
R is the general gas constant (R = 8.314 J/mol.K)
NA is Avogadros number (6.023 x 10²³ atoms/mol)
T is the temperature (measured in Kelvin).
- It is clear from the relation that K depends only on the temperature.
- So, N₂ gas at 50 °C has the highest average kinetic energy since it is at the higher temperature than other gases.
Answer:
The molecular weight of the unknown compound is 267.7 g/mol
Explanation:
Lowering vapor pressure → Colligative property where the vapor pressure of solution is lower than vapor pressure of pure solvent
ΔP = P° . Xm
0.526 atm - 0.501 atm = 0.025atm
0.025 atm = 0.526 atm . Xm
Xm = 0.025 atm / 0.526 atm → 0.0475 (mole fraction)
Mole fraction = Moles of solute / Total moles (solute + solvent)
0.0475 = Moles of solute / Moles of solute + Moles of solvent
We determine the moles of solvent → 116.2 g . 1mol / 58 g = 2 moles
0.0475 = Moles of solute / Moles of solute + 2
0.0475 moles of solute + 0.095 = Moles of solute
0.095 = Moles of solute - 0.0475 moles of solute
0.095 / 0.9525 = Moles of solute → 0.0997 moles
Molas mass = g/mol → 26.7 g / 0.0997 mol = 267.7 g/mol
Answer: The molarity of KBr in the final solution is 1.42M
Explanation:
We can calculate the molarity of the KBr in the final solution by dividing the total number of moles of KBr in the solution by the final volume of the solution.
We will first calculate the number of moles of KBr in the individual sample before mixing together
In the first sample:
Volume (V) = 35.0 mL
Concentration (C) = 1.00M
Number of moles (n) = C × V
n = (35.0mL × 1.00M)
n= 35.0mmol
For the second sample
V = 60.0 mL
C = 0.600 M
n = (60.0 mL × 0.600 M)
n = 36.0mmol
Therefore, we have (35.0 + 36.0)mmol in the final solution
Number of moles of KBr in final solution (n) = 71.0mmol
Now, to get the molarity of the final solution , we will divide the total number of moles of KBr in the solution by the final volume of the solution after evaporation.
Therefore,
Final volume of solution (V) = 50mL
Number of moles of KBr in final solution (n) = 71.0mmol
From
C = n / V
C= 71.0mmol/50mL
C = 1.42M
Therefore, the molarity of KBr in the final solution is 1.42M
11 with pemdas, you have to multiply all by 3