To solve this problem, we can use the ideal gas law equation:
PV = nRT
Where:
P = pressure
V = volume
n = number of moles
R = ideal gas constant
T = temperature
Since the pressure remains constant, we can say that:
n1/V1 = n2/V2
Initially, the cylinder contains 2.00 g of helium. We need to find the number of moles of helium in the cylinder:
n1 = m/M
n1 = 2.00g / 4.00g/mol
n1 = 0.50 mol
Initially, the volume is 2.00 L and the temperature is 25°C, which we need to convert to Kelvin:
T = 25°C + 273
T = 298K
Next, we can calculate the number of moles of helium in the cylinder after adding more helium and increasing the volume:
n2 = n1 * V1 / V2
n2 = 0.50 mol * 2.00 L / 2.70 L
n2 = 0.37 mol
To find out how many grams of helium were added to the cylinder, we need to find the difference between the total number of moles of helium after the addition and the initial number of moles:
n_added = n2 - n1
n_added = 0.37 mol - 0.50 mol
n_added = -0.13 mol
Because n_added is negative, it means that 0.13 mol of helium was removed from the cylinder. If we turn this into grams:
m_added = n_added * M
m_added = -0.13 mol * 4.00 g/mol
m_added = -0.52 g
Therefore, in order to maintain the same pressure as the volume was increased, 0.52 grams of helium were removed from the cylinder.
A cylinder with a movable piston contains 2.00g of helium ,at a temperature of 25°c. More helium was added to the cylinder and the volume was adjusted so that the gas pressure remained the same. How many grams of helium were added to the cylinder if the volume was changed from 2.00Lto 2.70L( temperature held constant)
1 answer