Given: 2libr + ba → babr2 + 2li in this chemical reaction, 325 grams of barium (ba) react completely. how many moles of lithium (li) are produced? a. 1.18 mol b. 2.37 mol c. 4.73 mol d. 16.4 mol e. 32.9 mol

4.73 mol (OPTION C)

In order to find the moles of Li produced by the reaction, we have to work from the known information (moles of barium), make a connection between the two species (mole ratio between barium and lithium), then we can calculate determine the moles of Lithium.

Balanced Equation:  2LiBr  +  Ba   →   BaBr₂  +  2Li

                       moles = mass ÷ molar mass

Since the mass of barium is 325 g and its molar mass is 137 g/mol,

then the moles of barium = 325 g ÷ 137 g/mol

                                          = 2.37 mol

Now to find the number of moles of Lithium,  compare the mole ratio of Barium to Lithium based on the stoichiometric values of the balance equation:

      mole ratio of Ba : Li is 1 : 2

    ∴ for every moles of barium in the reaction, there are two moles of Lithium produced

⇒ if moles of Ba = 2.37 moles

then moles of Li = 2.37 moles × 2 moles

                           =  4.74 moles (OPTION C)