Answer:
The answer to your question is: SiCl₄
Explanation:
Data
amount of Si 1.71 g
amount of Cl 8.63 g
MW Si = 28 g
MW Cl = 35.5
Process (rule of three)
For Si For Cl
28 g of Si ------------------ 1 mol 35.5 g of Cl --------------- 1 mol
1.71g of Si --------------- x 8.63 g of Cl -------------- x
x = 1.71 x 1 / 28 = 0.06 mol x = 8.63 x 1 / 35.5 = 0.24 mol
Now, divide both results by the lowest of them.
Si = 0.06 mol / 0.06 = 1 molecule of Si Cl = 0.24 / 0.06 = 4 molecules of Cl
Finally
Si₁ Cl₄ or SiCl₄
D = m / V
It even gives you the density of gold in the problem. Major hint. Once you know the volume (using V = m / D) then you can calculate the height (thickness) from the equation...
V = L x W x H
Volume = Length x Width x Height
start by converting 200.0 mg into grams
1000 mg = 1 g
200. mg x (1 g / 10^3 mg) = 0.200 g
V = m / D
V = 0.200 g / (19.32 g/cm^3)
V = 0.01035 cm^3
Convert 2.4 ft and 1 ft to cm
2.4 ft x (12 in / 1 ft) x (2.54 cm / 1 in) = 73.15 cm
1 ft = 30.48 cm
Compute the height (thickness)
V = LxWxH
H = V / LW = 0.01035 cm^3 / 73.15 cm / 30.48 cm
H = 4.64 x 10^-6 cm
Convert to nanometers
4.64 x 10^-6 cm x (1 m / 100 cm) x (10^9 nm / 1 m) = 46.4 nm
Knowing the atomic radius of gold, I might have asked my students for the minimum number of gold atoms in this thickness of gold. This would assume that the gold atoms are all in a row. This would give the minimum number of gold atoms.
Atomic radius gold = 174 pm
Diameter = 348 pm
46.4 nm x (1 m / 10^9 nm) x (10^12 pm / 1 m) x (1 Au atom / 248 pm) = 133 atoms of gold
Answer: The volume of gas is 3020 ml
Explanation:
According to ideal gas equation:
P = pressure of gas = 821.4 torr = 1.08 atm (760 torr = 1atm)
V = Volume of gas in L = ?
n = number of moles = 
R = gas constant =
T =temperature =
Thus volume of gas is 3020 ml
Answer: The mole fraction of benzene will be 0.34 and mole fraction of toluene is 0.66
Explanation:
According to Raoult's law, the vapor pressure of a component at a given temperature is equal to the mole fraction of that component multiplied by the vapor pressure of that component in the pure state.
and 
where, x = mole fraction in solution
= pressure in the pure state
According to Dalton's law, the total pressure is the sum of individual pressures.
,
,
Thus (1-x0 = (1-0.34)=0.66
Thus the mole fraction of benzene will be 0.34 and that of toluene is 0.66
