Final answer:
To determine the quantity of H₂ in H₃PO₄, we need to consider the balanced chemical equation for the reaction, use the molarity and volume to determine the moles of H₃PO₄, and then use the mole ratio to calculate the moles of H₂ produced.
Step-by-step explanation:
In order to determine the quantity of H2 in H3PO4, we need to consider the balanced chemical equation for the reaction. According to the equation: 2Cr + 2H3PO4 → 3H2 + 2CrPO4. From the equation, we can see that 2 moles of H3PO4 are required to produce 3 moles of H2. Therefore, the ratio of moles of H2 to moles of H3PO4 is 3:2.
Given that we have a 0.8775-M solution of H3PO4, we can use the molarity and volume to determine the moles of H3PO4.
Finally, using the mole ratio, we can calculate the moles of H2 produced.