Here's my best guess
the volume of the unit cell is (385*10^-12)^3=5.7066*10^-29 m^3
multiply by density to get mass
mass = (7 g/cm^3)*(100^3 cm^3 / 1^3 m^3) * 5.7066*10^-29 m^3= 3.99466*10^-22 g
covert to moles
3.99466*10^-22 g * 1 mol / 239.82 g = 1.6657 *10^-24 mol
convert to number of units
1.6657 *10^-24 mol * 6.23*10^23 units/mol = 1.04
385 pm = 3.85*10^(-8) cm
The volume of the unit cell is the cube of that, which is 5.71*10^(-23) cm^3. Since the ratio of mass to volume (i.e. the density) must be the same no matter what amount of TlCl you have, you can say:
7 = x/(5.71*10^(-23)), where x is the mass of the unit cell. Solving for x, you get 4*10^(-22) g.
The mass of a molecule of TlCl is 240 amu, which in grams is 4*10^(-22) g. The mass of the unit cell and the mass of a molecule of TlCl is the same. Therefore there is one formula unit of TlCl per unit cell.
initial condition : Vi = 4.700 L , Ti = 71.0ºC +273 => 344 K
final condition : Vf = 3.300 L , Tf = ?
Pressure is constant:
According to charle's law , volume is directly proportional to temperature at constant pressure !
Hence Vi / Ti = Vf / Tf
4.700 L / 344 K = 3.300 L / Tf
Tf = 3.300 L * 344 K / 4.700 L
Tf = 1135200 / 4.700
Tf = 241.53 K
Tf = 241.53 - 273
Tf = -31.47ºC
Answer:
1.10 × 10⁻¹² m
General Formulas and Concepts:
<u>Chemistry - Atomic Structure</u>
Speed of Light = Wavelength times Frequency
Explanation:
<u>Step 1: Define</u>
ν = 2.73 × 10²⁰ Hz
<u>Step 2: Find wavelength</u>
3.0 × 10⁸ m/s = λ(2.73 × 10²⁰ Hz)
λ = 1.0989 × 10⁻¹² m
<u>Step 3: Check</u>
<em>We are given 3 sig figs. Follow sig fig rules.</em>
1.0989 × 10⁻¹² m ≈ 1.10 × 10⁻¹² m
Answer:
B
Explanation:
A chemical reaction equation is balanced if the number of atoms of each element on the right hand side of the reaction equation is the same as the number of atoms of the same element on the left hand side of the reaction equation.
By inspection, the chemical reaction written in the question is a balanced chemical reaction equation.
However, the statement in option B that more molecules of N2 are needed to produce NH3 than molecules of H2 is a false statement since only one mole of N2 and three moles of H2 are required to produce NH3 according to the reaction equation as written in the question.
