Question

2.3 grams of sodium reacts with water and 0.080 grams of hydrogen has been collected what are the theoretical and percent yields of hydrogen gas?

Answer 1

Answer:

Theoretical yield = 0.1 g

Percent yield = 80%

Explanation:

Given data:

Mass of sodium = 2.3 g

Actual yield of hydrogen = 0.080 g

Theoretical yield = ?

Percent yield = ?

Solution:

Chemical equation:

2Na + 2H₂O    →  H₂ + 2NaOH

Number of moles of sodium:

Number of moles = mass/ molar mass

Number of moles = 2.3 g/ 23 g/mol

Number of moles = 0.1 mol

Now we will compare the moles of sodium with hydrogen to calculate the theoretical yield.

                       Na               :              H₂

                        2                :               1

                     0.1                 :             1/2×0.1 = 0.05 mol

Mass of hydrogen produced:

Mass = number of moles × molar mass

Mass = 0.05 mol × 2 g/mol

Mass = 0.1 g

Percent yield of hydrogen:

Percent yield = actual yield / theoretical yield ×100

Percent yield = 0.08 g/ 0.1 g×100

Percent yield = 0.8×100

Percent yield = 80%