Question

1) How many moles of gas occupy 58 L at a pressure of 2.2 atmospheres and a temperature

of 313 K?

Answer 1

Given Information ,

• Volume ,V = 58 L
• Pressure ,P = 2.2 atm
• Temperature ,T = 313

We have to find the number of moles .

We use here " Ideal Gas Equation" which is

• PV = nRT

where

n is number of moles

R is universal gas Constant

T is temperature

P is pressure

V is volume

On substituting the value we get

➣ 2.2 × 58 = n × 0.0821 × 313

➣ 127.6 = n × 25.70

➣ 127.6/25.70 = n

➣ 4.96 = n

➣ 5 ≈ n

So, the number of moles are 5 .

Answer 2

Here, we need to solve this problem using Ideal gas law ( PV=nRT).

Where –

• P = Pressure in atm
• V = Volume in L
• n = moles
• R = Ideal gas law constant
• T = Temperature in K

Now, according to the question –

• V = 58 L
• P = 2.2 atm
• T = 313 K
• R = 0.0821 atm L/ mol K

Calculation –

`\qquad`
`\pink{\twoheadrightarrow\bf PV = nRT}`

`\qquad`
`\twoheadrightarrow\sf n = (PV)/(RT)`

`\qquad`
`\twoheadrightarrow\sf n = \frac{ 2.2 \: \:* 58 \: } {0.0821 * 313}`

`\qquad`
`\twoheadrightarrow\sf n = ( 2.2 * 58)/(0.0821 * 313)`

`\qquad`
`\twoheadrightarrow\sf n =(127.6)/(25.7)`

`\qquad`
`\pink{\twoheadrightarrow\bf n = 4.9656 \: moles }`

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