Hi, I believe this question is asking what charge Phosphorus will have when it forms an ion. If that is the case, you will see that it based on the column it is in, neutral Phosphorus has 5 valence electrons. When it becomes an ion (has 8 valence electrons), it will GAIN three electrons. Meaning, we can predict that Phosphorus will have a 3- charge when it becomes an ion.
7.2 mol H × (1 mol H_2SO_4/2 mol H) = 3.6 mol H_2SO_4
This is what is normally termed a single replacement reaction, although don't hold me to that. It could have changed to something more modern.
Explanation:
Gay-Lussac's law states that if P=pressure and T=temperature, then P/T=P/T. Temperature must be in Kelvin, but pressure can be in any unit.
To convert Celsius into Kelvin, just add 273: 10+273=283K, and 28+273=301K.
So using the equation,
200kPa÷283=? kPa÷301
Solving this equation gives you about 212.72 kPa.