Which of the following compounds contains 57.5% sodium by mass?
*NaI
*NaOH
*NaHCO3
*NaSO3
NaOH
To determine which compound contains 57.5% sodium by mass, we need to calculate the molar masses of each compound and then compare the mass of sodium in the compound to the total mass of the compound.
The molar mass of NaI (sodium iodide) is 149.9 g/mol. The molar mass of NaOH (sodium hydroxide) is 40.0 g/mol. The molar mass of NaHCO3 (sodium bicarbonate) is 84.0 g/mol. The molar mass of Na2SO3 (sodium sulfite) is 126.0 g/mol.
Next, we'll calculate the mass of sodium in each compound.
For NaI:
(57.5/100) x 149.9 g/mol = 86.1775 g/mol
For NaOH:
(57.5/100) x 40.0 g/mol = 23.0 g/mol
For NaHCO3:
(57.5/100) x 84.0 g/mol = 48.3 g/mol
For Na2SO3:
(57.5/100) x 126.0 g/mol = 72.45 g/mol
Based on these calculations, the compound containing approximately 57.5% sodium by mass is Na2SO3 (sodium sulfite).
To determine which compound contains 57.5% sodium by mass, we need to calculate the percentage of sodium in each compound and compare it to the given value.
To do this, we can use the formula:
Percentage of Sodium = (Mass of Sodium / Total Mass of Compound) x 100
Let's calculate the percentages for each compound:
1. NaI:
- Sodium atomic mass = 23 g/mol
- Iodine atomic mass = 127 g/mol
- Total mass = 23 g/mol + 127 g/mol = 150 g/mol
- Percentage of Sodium = (23 g/mol / 150 g/mol) x 100 = 15.33%
2. NaOH:
- Sodium atomic mass = 23 g/mol
- Oxygen atomic mass = 16 g/mol
- Hydrogen atomic mass = 1 g/mol
- Total mass = 23 g/mol + 16 g/mol + 1 g/mol = 40 g/mol
- Percentage of Sodium = (23 g/mol / 40 g/mol) x 100 = 57.5%
3. NaHCO3:
- Sodium atomic mass = 23 g/mol
- Hydrogen atomic mass = 1 g/mol
- Carbon atomic mass = 12 g/mol
- Oxygen atomic mass = 16 g/mol (there are three oxygen atoms)
- Total mass = 23 g/mol + 1 g/mol + 12 g/mol + (16 g/mol x 3) = 84 g/mol
- Percentage of Sodium = (23 g/mol / 84 g/mol) x 100 = 27.38%
4. NaSO3:
- Sodium atomic mass = 23 g/mol
- Sulfur atomic mass = 32 g/mol
- Oxygen atomic mass = 16 g/mol (there are three oxygen atoms)
- Total mass = 23 g/mol + 32 g/mol + (16 g/mol x 3) = 87 g/mol
- Percentage of Sodium = (23 g/mol / 87 g/mol) x 100 = 26.44%
Based on the calculations, the compound that contains 57.5% sodium by mass is NaOH.
You omitted a 2 on Na2SO3. There is no NaSO3.
%Na in NaI = (atomic mass Na/molar mass NaI)*100 = ?
Do them until you find a 57.5% for Na.