mass fractions of scandium antimonide

Input interpretation

Image
Text

scandium antimonide | elemental composition

Result

Image
Text

$Find the elemental composition for scandium antimonide 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: ScSb Use the chemical formula to count the number of atoms, N_i, for each element and find the total number of atoms, N_atoms, per molecule: | number of atoms Sb (antimony) | 1 Sc (scandium) | 1 N_atoms = 1 + 1 = 2 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 Sb (antimony) | 1 | 1/2 Sc (scandium) | 1 | 1/2 Check: 1/2 + 1/2 = 1 Compute atom percents using the atom fractions: | number of atoms | atom percent Sb (antimony) | 1 | 1/2 × 100% = 50.0% Sc (scandium) | 1 | 1/2 × 100% = 50.0% 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 Sb (antimony) | 1 | 50.0% | 121.760 Sc (scandium) | 1 | 50.0% | 44.955908 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 Sb (antimony) | 1 | 50.0% | 121.760 | 1 × 121.760 = 121.760 Sc (scandium) | 1 | 50.0% | 44.955908 | 1 × 44.955908 = 44.955908 m = 121.760 u + 44.955908 u = 166.715908 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 Sb (antimony) | 1 | 50.0% | 121.760/166.715908 Sc (scandium) | 1 | 50.0% | 44.955908/166.715908 Check: 121.760/166.715908 + 44.955908/166.715908 = 1 Compute mass percents using the mass fractions: Answer: | | | number of atoms | atom percent | mass percent Sb (antimony) | 1 | 50.0% | 121.760/166.715908 × 100% = 73.03% Sc (scandium) | 1 | 50.0% | 44.955908/166.715908 × 100% = 26.97%$

Find the elemental composition for scandium antimonide 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: ScSb Use the chemical formula to count the number of atoms, N_i, for each element and find the total number of atoms, N_atoms, per molecule: | number of atoms Sb (antimony) | 1 Sc (scandium) | 1 N_atoms = 1 + 1 = 2 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 Sb (antimony) | 1 | 1/2 Sc (scandium) | 1 | 1/2 Check: 1/2 + 1/2 = 1 Compute atom percents using the atom fractions: | number of atoms | atom percent Sb (antimony) | 1 | 1/2 × 100% = 50.0% Sc (scandium) | 1 | 1/2 × 100% = 50.0% 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 Sb (antimony) | 1 | 50.0% | 121.760 Sc (scandium) | 1 | 50.0% | 44.955908 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 Sb (antimony) | 1 | 50.0% | 121.760 | 1 × 121.760 = 121.760 Sc (scandium) | 1 | 50.0% | 44.955908 | 1 × 44.955908 = 44.955908 m = 121.760 u + 44.955908 u = 166.715908 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 Sb (antimony) | 1 | 50.0% | 121.760/166.715908 Sc (scandium) | 1 | 50.0% | 44.955908/166.715908 Check: 121.760/166.715908 + 44.955908/166.715908 = 1 Compute mass percents using the mass fractions: Answer: | | | number of atoms | atom percent | mass percent Sb (antimony) | 1 | 50.0% | 121.760/166.715908 × 100% = 73.03% Sc (scandium) | 1 | 50.0% | 44.955908/166.715908 × 100% = 26.97%