Plastic is used to cover the copper wire in the power codes of appliances because plastic differs from copper in _________. 1. D
2 answers:
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Answer:
Explanation:
Given parameters:
Mass of MgCl₂ = 2.52 x 10⁻⁴g
Volume of water = 2L
Unkown:
Concentration of MgCl₂ =?
Concentration of Mg²⁺ = ?
Concentration of Cl⁻ =?
Solution:
Concentration is defined as the number of moles of a solute contained in a solution.
Concentration =
To find the number of moles"
number of moles =
Molar mass of MgCl₂ = 24.3 + (2 x 35.5) = 95.3g/mol
number of moles = = 0.000252moles
Concentration of MgCl₂ = = 2.64 x 10⁻⁶moldm⁻³
from the formula of the compound;
1 mole of MgCl₂ contains 1 mole of Mg²⁺
Therefore, 2.64 x 10⁻⁶moldm⁻³ of MgCl₂ will contains 2.64 x 10⁻⁶moldm⁻³ of Mg
Also;
1 mole of MgCl₂ contains 2 mole of Cl⁻
2.64 x 10⁻⁶moldm⁻³ contains 2 x 2.64 x 10⁻⁶moldm⁻³; 5.29 x 10⁻⁶moldm⁻³
Expressing in ppm;
1ppm = 1mg/L
2.64 x 10⁻⁶moldm⁻³ to mg/L for Mg²⁺
2.64 x 10⁻⁶moldm⁻³ = 2.64 x 10⁻⁶moldm⁻³ x molar mass(g/mol)
= 2.64 x 10⁻⁶moldm⁻³ x 24.3 = 6.43 x 10⁻⁵g/L
g/L to mg/L; 6.43 x 10⁻⁵g/L x 1000 = 6.43 x 10⁻²mg/L = 6.43 x 10⁻²ppm
5.29 x 10⁻⁶moldm⁻³ to mg/L for Cl⁻;
5.29 x 10⁻⁶moldm⁻³ = 5.29 x 10⁻⁶moldm⁻³ x 35.5 = 1.88 x 10⁻⁴g/L
g/L to mg/L; 1.88 x 10⁻⁴g/L x 1000 = 1.88 x 10⁻¹mg/L = 1.88 x 10⁻¹ppm
Answer:
Explanation:
From the information given :
we can understand the solute is glucose and the solvent is water,
So, the weight of glucose = 20.23 g
the molecular weight of glucose = 180.2 g/mol
weight of water = 95. 75 g
the molecular weight of water = 18.02 g/mol
pure vapor pressure of water at 27°C
moles of glucose = weight of glucose/ molecular weight of glucose
= 20.23/180.2
= 0.11 mole
moles of water = weight of water / molecular weight of water
= 95.75/18.02
= 5.31 mole
mole fraction of glucose (moles of glucose)/(moles of glucose+ moles of water)
0.11/(0.11 + 5.31)
0.0203
mole fraction of glucose (moles of water)/(moles of water+ moles of glucose)
5.31/ (5.31 + 0.11)
0.9797
Using Raoult's Law:
where:
= vapor pressure of the solution
= total vapor pressure of the solution
= vapor pressure of the solvent in the pure state
= mole fraction of solvent i.e. water
95.75 × 0.9797
93.81 mmHg
the total vapor pressure of the solution = 93.81 mmHg