Question

Шар объемом 5 л заполнен кислородом, масса которого 20г. Определить концентрацию молекул кислорода в шаре.

Answer 1

(кол-во в-ва)=m/M

(кол-во в-ва)=N/Na

Приравниваем и выражаем N

m/M=N/Na,  N=mNa/М=(0,02*6,02*10^23)/32*10^-3=3.75*10^23

n=N/V=3.75*10^23/0.005=750*10^23=7.5*10^25

(n - концентрация, все данные в СИ)

Answer 2

Calculating Oxygen Molecule Concentration in the Sphere

To determine the concentration of oxygen molecules in the sphere, we can use the formula:

Concentration (in molecules per unit volume) = Number of molecules / Volume

Given: - Volume of the sphere (V) = 5 L = 5000 cm^3 - Mass of oxygen in the sphere (m) = 20 g - Molar mass of oxygen (M) = 32 g/mol

We can calculate the number of moles of oxygen using the formula: Number of moles = Mass / Molar mass

Then, we can use Avogadro's number to convert moles to molecules: Number of molecules = Number of moles * Avogadro's number

Finally, we can calculate the concentration of oxygen molecules using the formula mentioned earlier.

Calculation Steps

1. Calculate the number of moles of oxygen: - Number of moles = Mass / Molar mass - Number of moles = 20 g / 32 g/mol - Number of moles ≈ 0.625 moles

2. Calculate the number of molecules of oxygen: - Avogadro's number = 6.022 x 10^23 molecules/mol - Number of molecules = Number of moles * Avogadro's number - Number of molecules ≈ 0.625 moles * 6.022 x 10^23 molecules/mol

3. Calculate the concentration of oxygen molecules: - Concentration = Number of molecules / Volume - Concentration ≈ (0.625 moles * 6.022 x 10^23 molecules/mol) / 5000 cm^3

Result

The concentration of oxygen molecules in the sphere is approximately calculated as per the above steps.