Input interpretation
![methane | molecular mass](../image_source/0a1f7d8087e76dc9c6b4b06df32d1b6b.png)
methane | molecular mass
Result
![Find the molecular mass, m, for methane: m = sum _iN_im_i Plan: • Write the chemical formula and gather atomic masses from the periodic table. • Determine values for N_i and m_i using these items. • Finally, compute the mass. Write the chemical formula: CH_4 Use the chemical formula to count the number of atoms, N_i, for each element: | N_i C (carbon) | 1 H (hydrogen) | 4 Look up the atomic mass, m_i, in unified atomic mass units, u, for each element in the periodic table: | N_i | m_i/u C (carbon) | 1 | 12.011 H (hydrogen) | 4 | 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: Answer: | | | N_i | m_i/u | mass/u C (carbon) | 1 | 12.011 | 1 × 12.011 = 12.011 H (hydrogen) | 4 | 1.008 | 4 × 1.008 = 4.032 m = 12.011 u + 4.032 u = 16.043 u](../image_source/9df15aecbcd2a47e030d5d6e616bd33b.png)
Find the molecular mass, m, for methane: m = sum _iN_im_i Plan: • Write the chemical formula and gather atomic masses from the periodic table. • Determine values for N_i and m_i using these items. • Finally, compute the mass. Write the chemical formula: CH_4 Use the chemical formula to count the number of atoms, N_i, for each element: | N_i C (carbon) | 1 H (hydrogen) | 4 Look up the atomic mass, m_i, in unified atomic mass units, u, for each element in the periodic table: | N_i | m_i/u C (carbon) | 1 | 12.011 H (hydrogen) | 4 | 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: Answer: | | | N_i | m_i/u | mass/u C (carbon) | 1 | 12.011 | 1 × 12.011 = 12.011 H (hydrogen) | 4 | 1.008 | 4 × 1.008 = 4.032 m = 12.011 u + 4.032 u = 16.043 u
Unit conversions
![16.04 Da (daltons)](../image_source/43d46d7e719f10d94c638925ccd00a06.png)
16.04 Da (daltons)
![0.01604 kDa (kilodaltons)](../image_source/e0446b9353e813f11dcadf24a250d66c.png)
0.01604 kDa (kilodaltons)
![2.664×10^-23 grams](../image_source/a02c155ecc3ea074e6214104afc3c16b.png)
2.664×10^-23 grams
![2.664×10^-26 kg (kilograms)](../image_source/e46e51195527159f50b4c0b9b0a5b61c.png)
2.664×10^-26 kg (kilograms)
![16.04 chemical atomic mass units (unit officially deprecated)](../image_source/d723acc3f8069cc68c9ec477826cabc5.png)
16.04 chemical atomic mass units (unit officially deprecated)
![16.05 physical atomic mass units (unit officially deprecated)](../image_source/ffcf134feb8b3f369a266cfdd552e74b.png)
16.05 physical atomic mass units (unit officially deprecated)
Comparisons as mass of molecule
![≈ ( 0.083 ≈ 1/12 ) × molecular mass of caffeine ( ≈ 194 u )](../image_source/5bc8e5aeae014297c8bf9f66fa0dec89.png)
≈ ( 0.083 ≈ 1/12 ) × molecular mass of caffeine ( ≈ 194 u )
![≈ 0.27 × molecular mass of sodium chloride ( ≈ 58 u )](../image_source/776b7ab8afd898423c559407469c29fe.png)
≈ 0.27 × molecular mass of sodium chloride ( ≈ 58 u )
![≈ 0.89 × molecular mass of water ( ≈ 18 u )](../image_source/a678c870ff3fcaaa328015d612dc5c22.png)
≈ 0.89 × molecular mass of water ( ≈ 18 u )
Corresponding quantities
![Relative atomic mass A_r from A_r = m_aN_A/M_u: | 16](../image_source/4a719e67c1e7830460909b5debbc7305.png)
Relative atomic mass A_r from A_r = m_aN_A/M_u: | 16
![Molar mass M from M = m_aN_A: | 16 g/mol (grams per mole)](../image_source/f165bcd17434f507d76f07580c522e0c.png)
Molar mass M from M = m_aN_A: | 16 g/mol (grams per mole)
![Relative molecular mass M_r from M_r = m_mN_A/M_u: | 16](../image_source/3ab0867c0890186b3ebcf65eba09c45c.png)
Relative molecular mass M_r from M_r = m_mN_A/M_u: | 16
![Molar mass M from M = m_mN_A: | 16 g/mol (grams per mole)](../image_source/8358c50ba5753abb3114f18b31fdeca9.png)
Molar mass M from M = m_mN_A: | 16 g/mol (grams per mole)