<span>1.16 moles/liter
The equation for freezing point depression in an ideal solution is
ΔTF = KF * b * i
where
ΔTF = depression in freezing point, defined as TF (pure) ⒠TF (solution). So in this case ΔTF = 2.15
KF = cryoscopic constant of the solvent (given as 1.86 âc/m)
b = molality of solute
i = van 't Hoff factor (number of ions of solute produced per molecule of solute). For glucose, that will be 1.
Solving for b, we get
ΔTF = KF * b * i
ΔTF/KF = b * i
ΔTF/(KF*i) = b
And substuting known values.
ΔTF/(KF*i) = b
2.15âc/(1.86âc/m * 1) = b
2.15/(1.86 1/m) = b
1.155913978 m = b
So the molarity of the solution is 1.16 moles/liter to 3 significant figures.</span>
Answer:
The formula of Quartz is SiO2. So, 1 mole of Quartz will have 2 moles of oxygen atoms, i.e. 2 x 6.022 x 10^23 atoms of oxygen. The molar mass of quartz is 60 g per mol. So, 60 g quartz means 1 mole quartz.
Explanation:
Answer:
The required volume of hexane is 0.66245 Liters.
Explanation:
Volume of octane = v=1.0 L=
Density of octane= d = 
Mass of octane ,m= 
Moles of octane =
Mole percentage of Hexane = 45%
Mole percentage of octane = 100% - 45% = 55%
Total moles = 11.212 mol
Moles of hexane :
Moles of hexane = 5.0454 mol
Mass of 5.0454 moles of hexane,M = 5.0454 mol × 86 g/mol=433.9044 g
Density of the hexane,D = 
Volume of hexane = V
(1 cm^3= 0.001 L)
The required volume of hexane is 0.66245 Liters.
Answer:
6⅔ shifts
Explanation:
From the question given:
A shift = 4 hours
Pay = $8.25 per hour
Next, we shall determine the number of hours that will result in a pay of $220. This can be obtained as follow:
$8.25 = 1 hour
Therefore,
$220 = $220 × 1 hour / $8.25
$220 = 220/8.25 hours.
$220 = 80/3 hours
$220 = 26⅔ hours
Therefore, it will take 26⅔ hours to receive a pay of $220.
Finally, we shall determine the number of shifts in 26⅔ hours. This can be obtained as follow:
4 hours = 1 shift
Therefore,
26⅔ hours = 26⅔ ÷ 4
26⅔ hours = 80/3 × 1/4
26⅔ hours = 80/12
26⅔ hours = 20/3
26⅔ hours = 6⅔ shifts
Therefore, she will work 6⅔ shifts in order to receive a pay of $220
