what mass of H2 is produced by the reaction of 118.5 mL of a 0.8775M solution of H3PO4 according to the following equation: 2Cr+2H3PO4= 3H2+2CrPO4
To find the mass of H2 produced, we need to use the given information and the stoichiometry of the balanced equation.
First, let's convert the volume of the H3PO4 solution to moles. We'll use the formula:
moles = Molarity × Volume (in liters)
Given:
Molarity of H3PO4 (H3PO4) = 0.8775 M
Volume of H3PO4 solution = 118.5 mL = 0.1185 L
moles of H3PO4 = 0.8775 M × 0.1185 L = 0.1039 moles
Next, we need to determine the stoichiometric ratio between H3PO4 and H2. According to the balanced equation:
2 H3PO4 produces 3 H2
Using the stoichiometry, we can determine the moles of H2 produced:
moles of H2 = (moles of H3PO4) × (3 moles of H2 / 2 moles of H3PO4)
= (0.1039 moles) × (3 / 2)
= 0.1558 moles
Finally, we can calculate the mass of H2 using the molar mass of H2 (2 grams/mol):
mass of H2 = (moles of H2) × (molar mass of H2)
= 0.1558 moles × 2 g/mol
= 0.3116 grams
Therefore, the mass of H2 produced by the given reaction is approximately 0.3116 grams.