Thickness of strand hair = 50 μm
Diameter of an atom = 
Now, with the help of conversion factors, convert thickness in micrometer into meter i.e. 1 micrometer = 
So, thickness of strand hair =50 μm= 50 \times 10^{-6} m
Therefore,
number of atoms thick is a strand of hair = 
= 
Hence, number of atoms is thick is a strand of hair.
Answer:
Molar mass = 94972.745 g/mol
Explanation:
Given data:
Density = 2.25 g/ml
Pressure = 700 mmHg
Temperature = 200°C
Molar mass = ?
Solution:
Density = 2.25 g/ml (2.25×1000 = 2250 g/L)
Pressure = 700 mmHg (700/760 = 0.92 atm)
Temperature = 200°C (200+273 = 473K)
Formula:
d = PM/RT
M = dRT/P
M = 2250 g/L × 0.0821 atm.L /mol.K × 473K / 0.92 atm
M = 87374.93 g/mol / 0.92
M = 94972.745 g/mol
The weighted average atomic mass of Silicon is 28.1
(27.98 x .9223) + (28.98 x .0468) + (29.97 x .0309)
= 25.81 + 1.36 + .93
= 28.1
it is covalent because it does not dissolve in water
Answer:
a) Xbenzene = 0.283
b) Xtoluene = 0.717
Explanation:
At T = 20°C:
⇒ vapor pressure of benzene (P*b) = 75 torr
⇒ vapor pressure toluene (P*t) = 22 torr
Raoult's law:
∴ Pi: partial pressure of i
∴ Xi: mole fraction
∴ P*i: vapor pressure at T
a) solution: benzene (b) + toluene (t)
∴ Psln = 37 torr; at T=20°C
⇒ Psln = Pb + Pt
∴ Pb = (Xb)*(P*b)
∴ Pt = (Xt)*(P*t)
∴ Xb + Xt = 1
⇒ Psln = 37 torr = (Xb)(75 torr) + (1 - Xb)(22 torr)
⇒ 37 torr - 22 torr = (75 torr)Xb - (22 torr)Xb
⇒ 15 torr = 53 torrXb
⇒ Xb = 15 torr / 53 torr
⇒ Xb = 0.283
b) Xb + Xt = 1
⇒ Xt = 1 - Xb
⇒ Xt = 1 - 0.283
⇒ Xt = 0.717
