How many atoms are contained in 5.77 grams of aluminum? Express your answer in exponential notation (Ex: 6.02*1023 would be ente
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Answer:
The molarity of urea in this solution is 6.39 M.
Explanation:
Molarity (M) is <em>the number of moles of solute in 1 L of solution</em>; that is
To calculate the molality, we need to know the number of moles of urea and the volume of solution in liters. We assume 100 grams of solution.
Our first step is to calculate the moles of urea in 100 grams of the solution,
using the molar mass a conversion factor. The total moles of 100g of a 37.2 percent by mass solution is
60.06 g/mol ÷ 37.2 g = 0.619 mol
Now we need to calculate the volume of 100 grams of solution, and we use density as a conversion factor.
1.032 g/mL ÷ 100 g = 96.9 mL
This solution contains 0.619 moles of urea in 96.9 mL of solution. To express it in molarity, we need to calculate the moles present in 1000 mL (1 L) of the solution.
0.619 mol/96.9 mL × 1000 mL= 6.39 M
Therefore, the molarity of the solution is 6.39 M.
Answer:
we will use the Clausius-Clapeyron equation to estimate the vapour pressures of the boiling ethanol at sea level pressure of 760mmHg:
ln (P2/P1) = -
)
where
P1 and P2 are the vapour pressures at temperatures T1 and T2
Δ vapH = the enthalpy of vaporization of the ETHANOL
R = the Universal Gas Constant
In this problem,
P 1 = 100 mmHg
; T 1 = 34.7 °C = 307.07 K
P 2 = 760mmHg
T 2 =T⁻²=?
Δ vap H = 38.6 kJ/mol
R = 0.008314 kJ⋅K -1 mol -1
ln ( 760/10)=(0.00325 - T⁻²) (38.6kJ⋅mol-1 /0.008314 )
0.0004368=(0.00325 - T⁻²)
T⁻²=0.002813
T² = 355.47K