what mass of phosphine oxide, is produced by the reaction of 15.0 g phosphine, 8.0 L oxygen at 25 degrees celcious and 755 mmHg
This is a limiting reagent problem. How do I know that? Because BOTH reactants are given.
1. Write the equation and balance it.
2. Convert 15.0 g PH3 to moles. moles = grams/molar mass.
3. Convert 8.0 L oxygen at the conditions listed to moles using PV = nRT.
4. Using the coefficients in the balanced equation, convert moles PH3 to moles of product.
5. Same process, convert moles O2 to moles of the product.
6. It is more than likely that the answers from 4 and 5 will not agree. The correct answer, in limiting reagent problems, is ALWAYS the smaller value and the reagent producing that value is the limiting reagent.
7. Using the smaller value from above, convert moles to grams of the product. g = moles x molar mass.
Post your work if you get stuck.