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3 years ago

What is the molar mass of an unknown gas with a density of 2.00 g/L at 1.00 atm and 25.0 °C?

Chemistry

1 answer:

soldier1979 [14.2K]3 years ago

7 0

Answer:

Explanation:Explanation:

Your starting point here will be the ideal gas law equation

∣

¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯

∣

−−−−−−−−−−−−−−−

, where

- the pressure of the gas

- the volume it occupies

- the number of moles of gas

- the universal gas constant, usually given as

0.0821

atm

⋅

mol

⋅

- the absolute temperature of the gas

Now, you will have to manipulate this equation in order to find a relationship between the density of the gas,

, under those conditions for pressure and temperature, and its molar mass,

You know that the molar mass of a substance tells you the mass of exactly one mole of that substance. This means that for a given mass

of this gas, you can express its molar mass as the ratio between

and

, the number of moles it contains

∣

¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯

∣

−−−−−−−−−−−−−

(

)

Similarly, the density of the substance tells you the mass of exactly one unit of volume of that substance.

This means that for the mass

of this gas, you can express its density as the ratio between

and the volume it occupies

∣

¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯

∣

−−−−−−−−−−−

(

)

Plug equation

(

)

into the ideal gas law equation to get

⋅

Rearrange to get

⋅

Finally, use equation

(

)

to write

⋅

Convert the temperature of the gas from degrees Celsius to Kelvin then plug in your values to find

1.02

⋅

0.0821

atm

⋅

mol

⋅

(

273.15

)

0.990

atm

∣

¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯

26.3 g mol

−

∣

−−−−−−−−−−−−−−−−

I'll leave the answer rounded to three

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Explanation:

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