Question

Рассчитать число молекул в 8г гелия (He) а так массу молекулы гелия

Answer 1

M=8*10^-3 кг    M=4*10^-3 кг/моль    N=?   mo=?
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N=m*Na/M=8*6*10^23/4=1.2*10^24 шт.
mo=m/N=8*10^-3/(1.2*10^24)=6.67*10^-27 кг
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Answer 2

Calculation of the Number of Molecules in 8g of Helium (He)

To calculate the number of molecules in 8g of helium (He), we need to use the concept of molar mass and Avogadro's number.

1. Determine the molar mass of helium (He): - The molar mass of helium is approximately 4 g/mol.

2. Calculate the number of moles of helium: - To calculate the number of moles, we divide the mass of helium (8g) by its molar mass (4 g/mol): ``` Number of moles = Mass / Molar mass = 8g / 4 g/mol = 2 mol ```

3. Use Avogadro's number to calculate the number of molecules: - Avogadro's number is approximately 6.022 x 10^23 molecules/mol. - Multiply the number of moles by Avogadro's number to get the number of molecules: ``` Number of molecules = Number of moles x Avogadro's number = 2 mol x 6.022 x 10^23 molecules/mol = 1.2044 x 10^24 molecules ```

Therefore, there are approximately 1.2044 x 10^24 molecules in 8g of helium (He).

Mass of a Helium Molecule

To calculate the mass of a helium molecule, we can use the molar mass of helium and Avogadro's number.

1. Determine the molar mass of helium (He): - The molar mass of helium is approximately 4 g/mol.

2. Use Avogadro's number to calculate the mass of a helium molecule: - Avogadro's number is approximately 6.022 x 10^23 molecules/mol. - Divide the molar mass of helium by Avogadro's number to get the mass of a helium molecule: ``` Mass of a helium molecule = Molar mass / Avogadro's number = 4 g/mol / (6.022 x 10^23 molecules/mol) = 6.646 x 10^-24 grams ```

Therefore, the mass of a helium molecule is approximately 6.646 x 10^-24 grams.

Please note that the values provided are approximate and may vary slightly depending on the source and the level of precision required.