Respuesta :

At STP 1 mole of gas occupies 22.4L. So you just multiply 1.7824g/L by 22.4L and the Liters cancel out. So the final answer is 39.92 and element Argon is closest to this mass so Argon is the element.

Answer: The molar mass of the element is 40 g/mol and element is Calcium.

Explanation:

At STP:

1 mole of a gas contains 22.4 L of volume

Molar mass is defined as the mass of 1 mole of a substance.

To calculate mass of of the substance, we use the equation:

[tex]\text{Density of substance}=\frac{\text{Mass of substance}}{\text{Volume of substance}}[/tex]

Volume of gas = 22.4 L

Density of gas = 1.7824 g/L

Putting values in above equation, we get:

[tex]1.7824g/L=\frac{\text{Mass of gas}}{22.4L}\\\\\text{Mass of gas}=(1.7824g/L\times 22.4L)=39.9g\approx 40g[/tex]

The element having molar mass 40 g is Calcium.

Hence, the molar mass of the element is 40 g/mol and element is Calcium.