Answer:
Mole fraction of solute is 0.0462
Explanation:
To solve this we use the colligative property of lowering vapor pressure.
First of all, we search for vapor pressure of pure water at 25°C = 23.8 Torr
Now, we convert the Torr to mmHg. Ratio is 1:1, so 23.8 Torr is 23.8 mmHg.
Formula for lowering vapor pressure is:
ΔP = P° . Xm
Where ΔP = P' (Vapor pressure of solution) - P° (Vapor pressure of pure solvent)
Xm = mole fraction
24.9 mmHg - 23.8 mmHg = 23mmHg . Xm
Xm = (24.9 mmHg - 23.8 mmHg) / 23mmHg
Xm = 0.0462
2.91 mol Al * ( 26.982 g Al / 1 mol Al) = 78.518 grams
Answer:
(a) C5H8O2
(b) C2H2Cl2
(c) CH2
(d) CH
Explanation:
We need to find the proportion of the atoms in whole numbers. Given the percentages we can calculate the number of moles and find their proportions.
Assume 100 g and given the atomic weights the moles are calculated.
(a) C = 59.9/ 12.01 = 4.98 ≈ 5.00
H = 8.06/1.007 = 8.00
O = 32/15.999 = 2.00
C5H8O2
(b) C= 24.8/12.01 = 2.06≈ 2.00
H = 2.0/1.007 = 1.99 ≈ 2.00
Cl = 73.1/ 35.453 = 2.06 ≈ 2.00
C2H2Cl2
(c) C = 86/12.01 = 7.16
H= 14/1.007 = 13.90
7.16:13.90 ≈ 1:2
CH2
(d) C = 92.30/12.01 = 7.68
H = 7.7 / 1.007 = 7.65
7.68:7.65 ≈ 1:1
CH
Answer:
It is expensive, largely because of the amount of electricity required in the extraction process. Aluminium ore is called bauxite . The bauxite is purified to produce aluminium oxide, a white powder from which aluminium can be extracted. The extraction is done by electrolysis.
Answer:
c. ammonia
Explanation:
Ammonia is a base, so it is most alkaline.
