Question

Monosodium glutamate (MSG) is added to food to enhance the flavor. Calculate the percent composition of MSG, \(\mathrm{NaC}_{5} \mathrm{H}_{8} \mathrm{NO}_{4}\).

Short answer

The percent compositions of MSG are Na: 13.59%, C: 35.52%, H: 4.77%, N: 8.28%, O: 37.84%.

Step-by-step solution

Understand the Molecular Formula

The given compound in this exercise is monosodium glutamate (MSG), which has the chemical formula \( \text{NaC}_5\text{H}_8\text{NO}_4 \). This formula indicates that MSG consists of sodium (Na), carbon (C), hydrogen (H), nitrogen (N), and oxygen (O) atoms.

Find Molar Mass of Each Element

Identify the atomic masses of the elements: \( \text{Na} = 22.99 \text{ g/mol}\), \(\text{C} = 12.01 \text{ g/mol}\), \(\text{H} = 1.008 \text{ g/mol}\), \(\text{N} = 14.01 \text{ g/mol}\), \(\text{O} = 16.00 \text{ g/mol}\).

Compute the Molar Mass of MSG

Use the molecular formula to calculate the total molar mass.\[ \text{Molar Mass} = 22.99 + (5 \times 12.01) + (8 \times 1.008) + 14.01 + (4 \times 16.00) \] Calculate each part: \( 22.99\, \text{(Na)} \), \( 5 \times 12.01 = 60.05\, \text{(C)} \), \( 8 \times 1.008 = 8.064\, \text{(H)} \), \( 14.01\, \text{(N)} \), \( 4 \times 16.00 = 64.00\, \text{(O)} \). Add them together: \( 22.99 + 60.05 + 8.064 + 14.01 + 64.00 = 169.114\, \text{g/mol} \).

Calculate Percent Composition for Each Element

Calculate the percent composition by dividing the molar mass of each element by the total molar mass of MSG and multiplying by 100%.\[ \text{Percent Composition} = \left( \frac{\text{Molar Mass of the Element}}{169.114} \right) \times 100\% \] - \(\% \text{Na} = \frac{22.99}{169.114} \times 100 = 13.59\% \)\[ \% \text{C} = \frac{60.05}{169.114} \times 100 = 35.52\% \] - \(\% \text{H} = \frac{8.064}{169.114} \times 100 = 4.77\% \)\[ \% \text{N} = \frac{14.01}{169.114} \times 100 = 8.28\% \] - \(\% \text{O} = \frac{64.00}{169.114} \times 100 = 37.84\% \).

Key concepts

Monosodium Glutamate

Monosodium glutamate, often abbreviated as MSG, is a flavor enhancer commonly added to foods, particularly in Asian cuisines. As its name suggests, MSG contains sodium, a component that contributes to the salty flavor profile. But MSG's most distinguishing feature is the umami taste it provides, a savory flavor that complements and enhances other tastes in foods.
MSG is synthesized from the naturally occurring amino acid, glutamic acid, which is found in many foods. It's important to note that while pure MSG is a chemical compound, glutamate occurs in a variety of foods such as tomatoes, cheese, and naturally in the human body. MSG works by stimulating the taste receptors and boosting the overall flavor of food without adding any extra calories. This is why it is a popular addition in food manufacturing.

Molecular Formula

The concept of a molecular formula is fundamental in chemistry. It represents the actual number of each type of atom in a molecule. In the case of monosodium glutamate (MSG), its molecular formula is \( \text{NaC}_5\text{H}_8\text{NO}_4 \). This precise formula tells us that each molecule of MSG contains:

• 1 sodium (Na) atom
• 5 carbon (C) atoms
• 8 hydrogen (H) atoms
• 1 nitrogen (N) atom
• 4 oxygen (O) atoms

Understanding molecular formulas helps in identifying the elements present in a compound and their respective quantities. This knowledge is essential when calculating properties like molar mass or when conducting reactions where the exact proportions of each element matter.
Additionally, the order in which the elements are presented in the formula can provide insights into the structure or characteristics of the compound, although for detailed structural information, structural formulas are used.

Molar Mass Calculation

Calculating the molar mass of a compound like monosodium glutamate is an essential skill in chemistry. The molar mass, expressed in grams per mole, is the sum of the atomic masses of all the atoms in a molecule's formula. Here's how you calculate it for MSG:First, identify the atomic masses of each element involved:

• Na (Sodium): 22.99 g/mol
• C (Carbon): 12.01 g/mol
• H (Hydrogen): 1.008 g/mol
• N (Nitrogen): 14.01 g/mol
• O (Oxygen): 16.00 g/mol

Then, plug these values into the formula:\[\text{Molar Mass of MSG} = 22.99 + (5 \times 12.01) + (8 \times 1.008) + 14.01 + (4 \times 16.00)\]Breaking this down:

• Na: 22.99 g/mol
• C: \(5 \times 12.01 = 60.05\;\text{g/mol}\)
• H: \(8 \times 1.008 = 8.064\;\text{g/mol}\)
• N: 14.01 g/mol
• O: \(4 \times 16.00 = 64.00\;\text{g/mol}\)

Add these together to get the total molar mass:\(22.99 + 60.05 + 8.064 + 14.01 + 64.00 = 169.114 \;\text{g/mol}\).
Understanding how to calculate the molar mass is vital for tasks like finding the percent composition of elements in a compound or predicting the quantities of reactants/products in a chemical reaction.