A level teaspoon may contain 4.0 grams of NaHCO3. How many moles does this represent?
To find the number of moles represented by 4.0 grams of NaHCO3, we need to use the molar mass of NaHCO3, which is calculated by adding up the atomic masses of its constituent elements.
The molecular formula of NaHCO3 is composed of one sodium (Na) atom, one hydrogen (H) atom, one carbon (C) atom, and three oxygen (O) atoms.
The atomic masses of these elements can be found on the periodic table:
- Sodium (Na) = 22.99 g/mol
- Hydrogen (H) = 1.01 g/mol
- Carbon (C) = 12.01 g/mol
- Oxygen (O) = 16.00 g/mol
So, the molar mass of NaHCO3 can be calculated as follows:
Molar mass of NaHCO3 = (1 * Na) + (1 * H) + (1 * C) + (3 * O)
= (1 * 22.99 g/mol) + (1 * 1.01 g/mol) + (1 * 12.01 g/mol) + (3 * 16.00 g/mol)
= 22.99 g/mol + 1.01 g/mol + 12.01 g/mol + 48.00 g/mol
= 84.01 g/mol
Now, using the calculated molar mass of NaHCO3, we can determine the number of moles represented by 4.0 grams of NaHCO3:
Number of moles = Mass of substance / Molar mass
= 4.0 g / 84.01 g/mol
Calculating this division, we find:
Number of moles ≈ 0.048 moles
Therefore, 4.0 grams of NaHCO3 represents approximately 0.048 moles.