Question

Вычислите массовую долю водорода в молекуле этаналя. С подробным решением, пожалуйста.

Answer 1

СН3СНО -  этаналь w(H)= m(H) * a / M( СН3СНО ) * 100%

 w(H)= 1 * 4 / 44 * 100% = 9%

 

 

Answer 2

Calculation of the Mass Fraction of Hydrogen in Ethanal

To calculate the mass fraction of hydrogen in ethanal (also known as acetaldehyde), we need to determine the molar mass of hydrogen and the molar mass of the entire ethanal molecule.

The molecular formula of ethanal is C2H4O, which means it contains 2 carbon atoms (C), 4 hydrogen atoms (H), and 1 oxygen atom (O).

The molar mass of hydrogen (H) is approximately 1.00784 g/mol, while the molar mass of carbon (C) is approximately 12.0107 g/mol, and the molar mass of oxygen (O) is approximately 15.999 g/mol.

To calculate the molar mass of ethanal, we multiply the number of atoms of each element by their respective molar masses and sum them up:

Molar mass of ethanal (C2H4O) = (2 * molar mass of carbon) + (4 * molar mass of hydrogen) + (1 * molar mass of oxygen)

Molar mass of ethanal = (2 * 12.0107 g/mol) + (4 * 1.00784 g/mol) + (1 * 15.999 g/mol)

Molar mass of ethanal = 24.0214 g/mol + 4.03136 g/mol + 15.999 g/mol

Molar mass of ethanal = 44.05176 g/mol

Now, to calculate the mass fraction of hydrogen in ethanal, we divide the molar mass of hydrogen by the molar mass of ethanal and multiply by 100%:

Mass fraction of hydrogen = (4 * molar mass of hydrogen) / molar mass of ethanal * 100%

Mass fraction of hydrogen = (4 * 1.00784 g/mol) / 44.05176 g/mol * 100%

Mass fraction of hydrogen = 4.03136 g/mol / 44.05176 g/mol * 100%

Mass fraction of hydrogen ≈ 9.16%

Therefore, the mass fraction of hydrogen in ethanal is approximately 9.16%.

Calculation Steps:

1. Determine the molar mass of hydrogen, carbon, and oxygen. 2. Calculate the molar mass of ethanal by summing the molar masses of its constituent atoms. 3. Divide the molar mass of hydrogen by the molar mass of ethanal and multiply by 100% to obtain the mass fraction of hydrogen.

Calculation Result:

The mass fraction of hydrogen in ethanal is approximately 9.16%.