Answer: 1.7 moles
Step-by-step explanation:
Given that:
Volume of water V = 1.5L
(since 1 liter = 1dm3
1.5L = 1.5dm3)
Temperature T = 100°C
Convert Celsius to Kelvin
(100°C + 273 = 373K)
Pressure P = 3.5 atm
Number of moles of steam N = ?
Note that Molar gas constant R is a constant with a value of 0.0082 ATM dm3 K-1 mol-1
Then, apply ideal gas equation
pV = nRT
3.5atm x 1.5dm3 = n x (0.0082 ATM dm3 K-1 mol-1 x 373K)
5.25 = n x 3.06
n = 5.25/3.06
n = 1.7 moles
Thus, 1.7 moles of steam is present