Question

A sample of helium is initially at 535 torr in a volume of 2.85 L.

If this sample of helium is at 24.7 °C, then What quantity in moles of
helium are present?

Answer 1

The quantity in moles of helium present is 41.63 moles.

Step-by-step explanation:

To find the quantity of moles of helium present in a sample, we can use the ideal gas law equation:

PV = nRT

Where P is the pressure, V is the volume, n is the number of moles, R is the ideal gas constant, and T is the temperature in Kelvin.

First, we need to convert the temperature from °C to Kelvin by adding 273.15. So, 24.7 °C is equal to 24.7 + 273.15 = 297.85 K.

Plugging in the given values:

535 torr x 2.85 L = n x (0.0821 L·atm/mol·K) x 297.85 K

Simplifying the equation, we can solve for n:

n = (535 torr x 2.85 L) / (0.0821 L·atm/mol·K x 297.85 K)

n = 41.63 moles of helium

Answer 2

There are 0.082 moles of He present.

Step-by-step explanation:

You would use the equation PV=nRT for this problem.

P (must convert to atm) = 535 torr/ 0.704 atm

V = 2.85 L

n = being solved for

R= 0.082 (universal gas constant for atm)

T (must convert to Kelvin) = 24.7 celsius/ 297.85 K

This equals:

0.704(2.85)= n (0.082)(297.85)

2.0064 =24.42n

n= 0.082 moles