Calculate mass (in grams) of sodium in 8.5 g of each sodium containing food additive. a. NaCl (table salt) b. Na₃PO₄ (sodium phosphate) c. NaC₇H₅O₂ (sodium benzoate) d. Na₂C₆H₆O₇ (sodium hydrogen citrate)

Key Concepts

Molar Mass

Molar mass is the mass of one mole of a substance, typically expressed in grams per mole (g/mol). For sodium chloride (NaCl), the molar mass is calculated by adding the atomic masses of sodium (Na) and chlorine (Cl), which are approximately 23 g/mol and 35.5 g/mol, respectively. This concept is essential for converting between grams and moles in stoichiometric calculations.

Stoichiometry

Stoichiometry is the area of chemistry that deals with the relationships between the quantities of reactants and products in chemical reactions. It allows us to calculate the amount of a substance in a mixture based on its proportion to other components. In this case, stoichiometry helps determine the mass of sodium in a given mass of NaCl by using the ratio of sodium's molar mass to the total molar mass of NaCl.

Mass Percentage

Mass percentage is a way of expressing the concentration of an element in a compound, calculated as the mass of the element divided by the total mass of the compound, multiplied by 100. For NaCl, the mass percentage of sodium can be found by dividing the molar mass of sodium by the molar mass of NaCl and then multiplying by 100. This concept is crucial for determining how much sodium is present in a specific mass of the additive.