Answer : The number of moles of argon gas is, 11.5 mol
Explanation :
To calculate the moles of argon we are using ideal gas equation as:
where,
P = pressure of argon gas = 658 mmHg = 0.866 atm (1 atm = 760 mmHg)
V = volume of argon gas = 30.6 L
n = number of moles of argon gas = ?
R = gas constant = 0.0821 L.atm/mol.K
T = temperature of argon gas = 28 K
Now put all the given values in the above formula, we get:
Therefore, the number of moles of argon gas is, 11.5 mol
The volume of the liquid from the graduated cylinder is 22.5 mL
The last option (22.5 mL) is the correct option
The question seems to be incomplete
The image that completes the question is shown in the attachment below.
From the image, we observe that the liquid meniscus is between the 20 mL and 25 mL marks. That means the volume will lie in this range.
NOTE: The meniscus of a liquid is the upward or downward curve seen at the top of a liquid in a container.
The type of curve shown in the image is a concave meniscus and the volume of the liquid is read from the bottom of the curve.
To read the value from the graduated cylinder, we will first determine the difference between two consecutive lines. Between the 20 mL and 25 mL mark (two thick lines), we have 5 spaces separated by thin lines.
The measure between two consecutive lines is the difference between two thick lines divided by number of spaces between them
∴ The measure between two consecutive lines = (25mL - 20mL) ÷ 5
The measure between two consecutive lines = 5mL ÷ 5 = 1 mL
Now, to read the position of the liquid,
Starting from the 20 mL mark, the liquid exceeds two more lines + half way to the next line ( that is 2mL + 0.5 mL)
∴ The position of the liquid is 20 mL + 2mL + 0.5 mL = 22.5 mL
Hence, the volume of the liquid from the graduated cylinder is 22.5 mL
Learn more here: brainly.com/question/19240870
