Question

a sample of an unknown gas has a mass of 0.582g. it's volume is 21.3 mL a a temp of 100 degrees Celsius and a pressure of 754 mmHg. determine the molar mass

Answer 1

To calculate the molar mass of the unknown gas, the Ideal Gas Law is used with the given mass, volume, temperature, and pressure. After converting to SI units and rearranging the equation to solve for moles, the molar mass is found by dividing the mass by the number of moles.

Step-by-step explanation:

To determine the molar mass of an unknown gas given its mass, volume, temperature, and pressure, we can use the Ideal Gas Law: 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. To find the molar mass (MM), we know the following:

Mass of the gas = 0.582 g

Volume (V) = 21.3 mL or 0.0213 L

Temperature (T) = 100 degrees Celsius or 373 K

Pressure (P) = 754 mmHg or 0.993 atm (conversion: 1 atm = 760 mmHg)

We first convert units to SI units and then rearrange the equation to solve for n (n = PV/RT). Finally, we calculate molar mass by taking the mass of the gas and dividing it by the number of moles (MM = mass/n).

Using these steps and the Ideal Gas Law, you can determine the molar mass for the unknown gas sample provided.

Answer 2

Molar mass = 0.09 × 10⁴ g/mol

Step-by-step explanation:

Given data:

Mass = 0.582 g

Volume = 21.3 mL

Temperature = 100°C

Pressure = 754 mmHg

Molar mass = ?

Solution:

(21.3 /1000 = 0.0213 L)

(100+273= 373 K)

(754/760 = 0.99 atm)

PV = nRT

n = PV/RT

n = 0.99 atm × 0.0213 L / 0.0821 atm. L. mol⁻¹. k⁻¹ × 373 K

n =0.02 mol/ 30.6

n = 6.5 × 10⁻⁴ mol

Molar mass = Mass/ number of moles

Molar mass = 0.582 g / 6.5 × 10⁻⁴ mol

Molar mass = 0.09 × 10⁴ g/mol