mass fractions of 2-hexyne

Input interpretation

Image
Text

2-hexyne | elemental composition

Result

Image
Text

$Find the elemental composition for 2-hexyne in terms of the atom and mass percents: atom percent = N_i/N_atoms × 100% mass percent = (N_im_i)/m × 100% Plan: • Write the chemical formula and gather atomic masses from the periodic table. • Determine values for N_i, m_i, N_atoms and m using these items. • Finally, compute the percents and check the results. Write the chemical formula: CH_3CH_2CH_2C congruent CCH_3 Use the chemical formula, CH_3CH_2CH_2C congruent CCH_3, to count the number of atoms, N_i, for each element and find the total number of atoms, N_atoms: | number of atoms C (carbon) | 6 H (hydrogen) | 10 N_atoms = 6 + 10 = 16 Divide each N_i by N_atoms to calculate atom fractions. Then use the property that atom fractions must sum to one to check the work: | number of atoms | atom fraction C (carbon) | 6 | 6/16 H (hydrogen) | 10 | 10/16 Check: 6/16 + 10/16 = 1 Compute atom percents using the atom fractions: | number of atoms | atom percent C (carbon) | 6 | 6/16 × 100% = 37.5% H (hydrogen) | 10 | 10/16 × 100% = 62.5% Look up the atomic mass, m_i, in unified atomic mass units, u, for each element in the periodic table: | number of atoms | atom percent | atomic mass/u C (carbon) | 6 | 37.5% | 12.011 H (hydrogen) | 10 | 62.5% | 1.008 Multiply N_i by m_i to compute the mass for each element. Then sum those values to compute the molecular mass, m: | number of atoms | atom percent | atomic mass/u | mass/u C (carbon) | 6 | 37.5% | 12.011 | 6 × 12.011 = 72.066 H (hydrogen) | 10 | 62.5% | 1.008 | 10 × 1.008 = 10.080 m = 72.066 u + 10.080 u = 82.146 u Divide the mass for each element by m to calculate mass fractions. Then use the property that mass fractions must sum to one to check the work: | number of atoms | atom percent | mass fraction C (carbon) | 6 | 37.5% | 72.066/82.146 H (hydrogen) | 10 | 62.5% | 10.080/82.146 Check: 72.066/82.146 + 10.080/82.146 = 1 Compute mass percents using the mass fractions: Answer: | | | number of atoms | atom percent | mass percent C (carbon) | 6 | 37.5% | 72.066/82.146 × 100% = 87.73% H (hydrogen) | 10 | 62.5% | 10.080/82.146 × 100% = 12.27%$

Find the elemental composition for 2-hexyne in terms of the atom and mass percents: atom percent = N_i/N_atoms × 100% mass percent = (N_im_i)/m × 100% Plan: • Write the chemical formula and gather atomic masses from the periodic table. • Determine values for N_i, m_i, N_atoms and m using these items. • Finally, compute the percents and check the results. Write the chemical formula: CH_3CH_2CH_2C congruent CCH_3 Use the chemical formula, CH_3CH_2CH_2C congruent CCH_3, to count the number of atoms, N_i, for each element and find the total number of atoms, N_atoms: | number of atoms C (carbon) | 6 H (hydrogen) | 10 N_atoms = 6 + 10 = 16 Divide each N_i by N_atoms to calculate atom fractions. Then use the property that atom fractions must sum to one to check the work: | number of atoms | atom fraction C (carbon) | 6 | 6/16 H (hydrogen) | 10 | 10/16 Check: 6/16 + 10/16 = 1 Compute atom percents using the atom fractions: | number of atoms | atom percent C (carbon) | 6 | 6/16 × 100% = 37.5% H (hydrogen) | 10 | 10/16 × 100% = 62.5% Look up the atomic mass, m_i, in unified atomic mass units, u, for each element in the periodic table: | number of atoms | atom percent | atomic mass/u C (carbon) | 6 | 37.5% | 12.011 H (hydrogen) | 10 | 62.5% | 1.008 Multiply N_i by m_i to compute the mass for each element. Then sum those values to compute the molecular mass, m: | number of atoms | atom percent | atomic mass/u | mass/u C (carbon) | 6 | 37.5% | 12.011 | 6 × 12.011 = 72.066 H (hydrogen) | 10 | 62.5% | 1.008 | 10 × 1.008 = 10.080 m = 72.066 u + 10.080 u = 82.146 u Divide the mass for each element by m to calculate mass fractions. Then use the property that mass fractions must sum to one to check the work: | number of atoms | atom percent | mass fraction C (carbon) | 6 | 37.5% | 72.066/82.146 H (hydrogen) | 10 | 62.5% | 10.080/82.146 Check: 72.066/82.146 + 10.080/82.146 = 1 Compute mass percents using the mass fractions: Answer: | | | number of atoms | atom percent | mass percent C (carbon) | 6 | 37.5% | 72.066/82.146 × 100% = 87.73% H (hydrogen) | 10 | 62.5% | 10.080/82.146 × 100% = 12.27%