Question

The product of the pressure and volume of a sample of hydrogen gas at 0.00°C is 80.0 J.

(a) How many moles of hydrogen are present?

a) 1.0 mol
b) 2.0 mol
c) 3.0 mol
d) 4.0 mol

Answer 1

To find the number of moles of hydrogen present, we can use the ideal gas law equation n = (pV) / (RT) and substitute the given values. In this case, there are approximately 3.04 moles of hydrogen present.

Step-by-step explanation:

To find the number of moles of hydrogen present, we need to rearrange the ideal gas law equation pV = nRT to solve for n, the number of moles. The equation becomes n = (pV) / (RT), where p is the pressure, V is the volume, R is the ideal gas constant, and T is the temperature in Kelvin. Since we are given the pressure, volume, and temperature, we can substitute these values into the equation to find the number of moles. However, it's important to convert the temperature from Celsius to Kelvin by adding 273.15 to it.

Given:

• Pressure (p) = ? (unknown)
• Volume (V) = ? (unknown)
• Temperature (T) = 0.00°C
• Number of moles (n) = ? (unknown)
• Ideal Gas Constant (R) = 8.314 J/(mol·K)
• Product of pressure and volume (pV) = 80.0 J

Using the equation n = (pV) / (RT), we can substitute the given values:

n = (80.0 J) / (8.314 J/(mol·K) * (0.00°C + 273.15))

Simplifying this equation gives us:

n ≈ 3.04 mol

Therefore, there are approximately 3.04 moles of hydrogen present. So the correct answer is option c) 3.0 mol.