Question

Расчитать массовую долю гидрогена в соединениях CH4 ; CaH2

Answer 1

W(CH4)=4\16=0.25

W(CaH2) = 2/65 =0.03

Answer 2

Calculation of Mass Fraction of Hydrogen in CH4 and CaH2

To calculate the mass fraction of hydrogen in the compounds CH4 (methane) and CaH2 (calcium hydride), we need to determine the molar masses of hydrogen and the respective compounds.

The molar mass of hydrogen (H) is approximately 1.008 g/mol.

The molar mass of methane (CH4) can be calculated by summing the molar masses of carbon (C) and hydrogen (H). The molar mass of carbon is approximately 12.01 g/mol Therefore, the molar mass of methane is:

Molar mass of CH4 = (1 * molar mass of C) + (4 * molar mass of H) = (1 * 12.01 g/mol) + (4 * 1.008 g/mol) = 12.01 g/mol + 4.032 g/mol = 16.042 g/mol

The molar mass of calcium hydride (CaH2) can be calculated by summing the molar masses of calcium (Ca) and hydrogen (H). The molar mass of calcium is approximately 40.08 g/mol Therefore, the molar mass of calcium hydride is:

Molar mass of CaH2 = (1 * molar mass of Ca) + (2 * molar mass of H) = (1 * 40.08 g/mol) + (2 * 1.008 g/mol) = 40.08 g/mol + 2.016 g/mol = 42.096 g/mol

Now, we can calculate the mass fraction of hydrogen in each compound.

For CH4: Mass fraction of hydrogen in CH4 = (4 * molar mass of H) / molar mass of CH4 = (4 * 1.008 g/mol) / 16.042 g/mol = 4.032 g/mol / 16.042 g/mol ≈ 0.2517

For CaH2: Mass fraction of hydrogen in CaH2 = (2 * molar mass of H) / molar mass of CaH2 = (2 * 1.008 g/mol) / 42.096 g/mol = 2.016 g/mol / 42.096 g/mol ≈ 0.0479

Therefore, the mass fraction of hydrogen in CH4 is approximately 0.2517 or 25.17%, and the mass fraction of hydrogen in CaH2 is approximately 0.0479 or 4.79%.

Please note that these calculations are approximate and may vary slightly depending on the exact molar masses used.

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