Monosodium glutamate (MSG), a food-flavor enhancer, has been blamed for “Chinese Restaurant Syndrome,” the symptoms of which are headaches & chest pains. MSG has the following composition by mass: 35.51 percent C, 4.77 percent H, 37.85 percent O, 8.29 percent N, & 13.60 percent Na. What is its molecular formula if its molar mass is about 169 g

Take a 100 g sample and that gives you

35.51 g C
4.77 g H
37.85 g O
8.29 g N
13.60 g Na

Convert g to mols. mol = g/molar mass

Then you want to find the ratio of these elements to each other with the smallest being no less than 1.00. The easy way to do that is to divide the smallest mols value by itself; then follow suit with the other numbers divided by the same small number. Round to the nearest whole number and that should give you the empirical formula. The molecular formula will be a multiple (1 or 2 or 3 etc) of the empirical formula. You can find the multiple by
empirical formula x ?number = 169.
Round ? number to a whole number.
Post your work if you get stuck.

sadw

To determine the molecular formula of monosodium glutamate (MSG), we need to calculate the empirical formula first and then the molecular formula.

1. Start by assuming we have 100g of MSG. We can then calculate the mass of each element in grams:

- Carbon (C): 35.51% of 100g = 35.51g
- Hydrogen (H): 4.77% of 100g = 4.77g
- Oxygen (O): 37.85% of 100g = 37.85g
- Nitrogen (N): 8.29% of 100g = 8.29g
- Sodium (Na): 13.60% of 100g = 13.60g

2. Next, convert the masses of each element to moles by dividing each mass by its respective molar mass:

- Carbon (C): 35.51g / 12.01 g/mol = 2.96 mol
- Hydrogen (H): 4.77g / 1.01 g/mol = 4.72 mol
- Oxygen (O): 37.85g / 16.00 g/mol = 2.36 mol
- Nitrogen (N): 8.29g / 14.01 g/mol = 0.59 mol
- Sodium (Na): 13.60g / 22.99 g/mol = 0.59 mol

3. Determine the mole ratio by dividing the number of moles of each element by the smallest number of moles:

- Carbon (C): 2.96 mol / 0.59 mol = 5
- Hydrogen (H): 4.72 mol / 0.59 mol = 8
- Oxygen (O): 2.36 mol / 0.59 mol = 4
- Nitrogen (N): 0.59 mol / 0.59 mol = 1
- Sodium (Na): 0.59 mol / 0.59 mol = 1

4. Write the empirical formula using the mole ratios determined:

The empirical formula for MSG is C5H8NO4Na.

5. Finally, to find the molecular formula, we need to know the molar mass of the empirical formula. The given molar mass is approximately 169 g.

Divide the molar mass by the empirical formula mass to find the whole number ratio:

Approximate molar mass of C5H8NO4Na = (12.01 * 5) + (1.01 * 8) + (14.01 * 1) + (16.00 * 4) + (22.99 * 1) ≈ 169 g/mol

Molar mass ratio = 169 g/mol / empirical formula mass ≈ 169 g/mol / 169 g/mol = 1

Since the molar mass ratio is 1, the molecular formula is the same as the empirical formula:

The molecular formula for MSG is C5H8NO4Na.

To find the molecular formula of monosodium glutamate (MSG), we need to determine the empirical formula first. The empirical formula represents the simplest, whole-number ratio of atoms in a compound.

To find the empirical formula, we need to convert the percentage composition to moles of each element. Here's how you can do it:

1. Assume we have a 100g sample of monosodium glutamate. This means that there would be 35.51g of carbon (C), 4.77g of hydrogen (H), 37.85g of oxygen (O), 8.29g of nitrogen (N), and 13.60g of sodium (Na) in the sample.

2. Convert the mass of each element to moles by dividing the mass by their respective atomic masses:

- Carbon (C): 35.51g / 12.01 g/mol = 2.95 mol
- Hydrogen (H): 4.77g / 1.01 g/mol = 4.72 mol
- Oxygen (O): 37.85g / 16.00 g/mol = 2.36 mol
- Nitrogen (N): 8.29g / 14.01 g/mol = 0.59 mol
- Sodium (Na): 13.60g / 22.99 g/mol = 0.59 mol

3. Find the simplest ratio of the moles by dividing each value by the smallest number of moles. In this case, the smallest number is 0.59 mol:

- Carbon (C): 2.95 mol / 0.59 mol = 5
- Hydrogen (H): 4.72 mol / 0.59 mol = 8
- Oxygen (O): 2.36 mol / 0.59 mol = 4
- Nitrogen (N): 0.59 mol / 0.59 mol = 1
- Sodium (Na): 0.59 mol / 0.59 mol = 1

The empirical formula based on these ratios is C5H8NO4Na.

To calculate the molecular formula, we need to determine the molar mass of the empirical formula. The molar mass of the empirical formula (C5H8NO4Na) is:

(5 x 12.01 g/mol) + (8 x 1.01 g/mol) + (1 x 14.01 g/mol) + (4 x 16.00 g/mol) + (1 x 22.99 g/mol) = 169.17 g/mol

Since the given molar mass of the compound is approximately 169 g/mol, the empirical and molecular formulas are the same in this case. Therefore, the molecular formula of monosodium glutamate (MSG) is C5H8NO4Na.