Input interpretation
![ammonia | molecular mass](../image_source/ae1f5dfec821b618fc1dd50cfab9216e.png)
ammonia | molecular mass
Result
![Find the molecular mass, m, for ammonia: 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: NH_3 Use the chemical formula to count the number of atoms, N_i, for each element: | N_i H (hydrogen) | 3 N (nitrogen) | 1 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 H (hydrogen) | 3 | 1.008 N (nitrogen) | 1 | 14.007 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 H (hydrogen) | 3 | 1.008 | 3 × 1.008 = 3.024 N (nitrogen) | 1 | 14.007 | 1 × 14.007 = 14.007 m = 3.024 u + 14.007 u = 17.031 u](../image_source/ef02c682d9e46be2c8b32f94b0cb5885.png)
Find the molecular mass, m, for ammonia: 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: NH_3 Use the chemical formula to count the number of atoms, N_i, for each element: | N_i H (hydrogen) | 3 N (nitrogen) | 1 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 H (hydrogen) | 3 | 1.008 N (nitrogen) | 1 | 14.007 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 H (hydrogen) | 3 | 1.008 | 3 × 1.008 = 3.024 N (nitrogen) | 1 | 14.007 | 1 × 14.007 = 14.007 m = 3.024 u + 14.007 u = 17.031 u
Unit conversions
![17.031 Da (daltons)](../image_source/f7c49b0ab305b3f722b5960b02a7f713.png)
17.031 Da (daltons)
![0.017031 kDa (kilodaltons)](../image_source/d0cef40e8c4f27698d8df62bea964e83.png)
0.017031 kDa (kilodaltons)
![2.8281×10^-23 grams](../image_source/d77bd0daf614cbf14b4e041d94d9f587.png)
2.8281×10^-23 grams
![2.8281×10^-26 kg (kilograms)](../image_source/bcbfb24cdb971b2b6cef327336ce76d6.png)
2.8281×10^-26 kg (kilograms)
![17.032 chemical atomic mass units (unit officially deprecated)](../image_source/4b3568f4175f7157742559bb9d64f0c3.png)
17.032 chemical atomic mass units (unit officially deprecated)
![17.036 physical atomic mass units (unit officially deprecated)](../image_source/676f82a1dc02a00f7b260910162e97c5.png)
17.036 physical atomic mass units (unit officially deprecated)
Comparisons as mass of molecule
![≈ ( 0.088 ≈ 1/11 ) × molecular mass of caffeine ( ≈ 194 u )](../image_source/b485f082710b99d6648e910acd3778cb.png)
≈ ( 0.088 ≈ 1/11 ) × molecular mass of caffeine ( ≈ 194 u )
![≈ 0.29 × molecular mass of sodium chloride ( ≈ 58 u )](../image_source/53e546f6017f1e53cdbc2eb39fb9a9e7.png)
≈ 0.29 × molecular mass of sodium chloride ( ≈ 58 u )
![≈ 0.95 × molecular mass of water ( ≈ 18 u )](../image_source/bb151d928358e8f7d89a62c8c68cb416.png)
≈ 0.95 × molecular mass of water ( ≈ 18 u )
Corresponding quantities
![Relative atomic mass A_r from A_r = m_aN_A/M_u: | 17](../image_source/6943ce42b052aade5fd669dd3818a798.png)
Relative atomic mass A_r from A_r = m_aN_A/M_u: | 17
![Molar mass M from M = m_aN_A: | 17 g/mol (grams per mole)](../image_source/9c3b22c470103ef4ae855d6cf245d1f6.png)
Molar mass M from M = m_aN_A: | 17 g/mol (grams per mole)
![Relative molecular mass M_r from M_r = m_mN_A/M_u: | 17](../image_source/463effa92b00003aa88ce56a0b0f1c34.png)
Relative molecular mass M_r from M_r = m_mN_A/M_u: | 17
![Molar mass M from M = m_mN_A: | 17 g/mol (grams per mole)](../image_source/91667f7ac905529b3542acabc8c92b2c.png)
Molar mass M from M = m_mN_A: | 17 g/mol (grams per mole)