Answer:
1.23 M
Explanation:
Molarity of a substance , is the number of moles present in a liter of solution .
M = n / V
M = molarity
V = volume of solution in liter ,
n = moles of solute ,
Moles is denoted by given mass divided by the molecular mass ,
Hence ,
n = w / m
n = moles ,
w = given mass ,
m = molecular mass .
From the question ,
w = given mass of NaCl = 7.2 g
As we know , the molecular mass of NaCl = 58.5 g/mol
Moles is calculated as -
n = w / m = 7.2 g / 58.5 g/mol = 0.123 mol
Molarity is calculated as -
V = 100ml = 0.1 L (since , 1 ml = 1/1000L )
M = n / V = 0.123 mol / 0.1 L = 1.23 M
In the first distillation this week, Hexane from the original solvent makes a larger contribution to the vapor pressure of the mixture.
In between hexane and toluene, the hexane will have more vapor pressure contribution in the solution. The boiling point of hexane is much lower than toluene. Therefore, it will evaporate easily at low temperatures and start exerting pressure on the solution.
Hence between hexane and toluene, because of more vapor pressure of hexane and lower boiling point, it will easily evaporate and exerts pressure.
Therefore, from the original solvent, hexane makes a larger contribution to the vapor pressure of the mixture.
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Answer:
Explanation:
2S + 3O₂ = 2SO₃
2moles 3 moles
2 moles of S react with 3 moles of O₂
5 moles of S will react with 3 x 5 / 2 moles of O₂
= 7.5 moles of O₂ .
O₂ remaining unreacted = 10 - 7.5 = 2.5 moles .
All the moles of S will exhausted in the reaction and 2.5 moles of oxygen will be left .
Answer:
Explanation:
a ) false.
NH₃ is more polar molecule than PH₃ so inter-molucular attraction is greater in NH₃ ( hydrogen bond ) . Hence vapour pressure is low for NH₃ .
b ) false .
The average kinetic energy of boiling water molecules is lower on a mountaintop than it is at sea level. It is so because water boils at lower temperture on mountain and kinetic energy of molecules depends upon temperature .
c ) false
vapour pressure depends upon temperature .
d ) True
CCl4 is more volatile than CBr4
e ) false
vapour pressure increases as temperature increases.
Answer:
i may be smart... but right now all I want is points
Explanation: