Regents Chemistry June 2026 15 At STP, which sample contains the same number of molecules as 20.0 liters of N2(g) at STP? (1) 10.0 L of H2(g) (3) 30.0 L of F2(g) (2) 20.0 L of CO2(g) (4) 40.0 L of SO2(g) Solution: STP stands for standard temperature and pressure. At the same temperature and pressure, in order for two samples of gas to have the same number of molecules, they have to have the same volume as well. Since nitrogen gas has a volume of 20L, the gas with the same num

Regents Chemistry June 2026 14 What is the pressure of 77 kPa expressed in atmospheres? (1) 0.76 atm (2) 1.3 atm (3) 77 atm (4) 7800 atm Solution: We can check the Chemistry Reference Table to check the conversion of kPa and atmospheres. Table 1 shows that 101.3kPa is 1 atm. Now lets set up the conversion. 77kPa *(1atm/101.3kPa) = 0.76atm. Choice 1 is the correct answer choice. LINKS: Regents Chemistry Guides and Solutions Chemistry Tutoring More Regents Chemistry Practice