If the atmospheric pressure in the laboratory is 1.2 atm, how many moles of gas were in each syringe?

air(h2o) syringe
room temperature water at 21.3 degrees celsius
volume of 5.1 ml

hydrogen(h2) syringe
room temperature water at 21.3 degrees celsius
volume of 5.2 ml

A: 2.525 x 10⁻⁴ mol

B: 2.583 x 10⁻⁴ mol

Explanation:

Part A:

Data Given:

Convert Temperature to Kelvin

T = °C + 273

T = 21.3 + 273 = 294.3 K

Convert mL to liter

1000 mL = 1 L

5.1 ml = 5.1/1000 = 0.0051 L

Solution

no. of moles can be calculated by using ideal gas formula

                         PV = nRT

Rearrange the equation for no. of moles

                          n= PV / RT . . . . . . . . . (1)

where

P = pressure

V = Volume

T= Temperature

n = Number of moles

R = ideal gas constant

where

R = 0.08206 L.atm / mol. K

Now put the value in formula (1) to calculate no. of moles of

              n = 1.2 atm x 0.0051 L / 0.08206 L.atm.mol⁻¹. K⁻¹ x 294.3 K

              n = 0.0061 atm.L / 24.162 L.atm.mol⁻¹

              n = 2.525 x 10⁻⁴ mol

no. of moles of gas (H₂O) = 2.525 x 10⁻⁴ mol

Part B:

Data Given:

Convert Temperature to Kelvin

T = °C + 273

T = 21.3 + 273 = 294.3 K

Convert mL to liter

1000 mL = 1 L

5.2 ml = 5.2/1000 = 0.0052 L

Solution

no. of moles can be calculated by using ideal gas formula

                         PV = nRT

Rearrange the equation for no. of moles

                         n= PV / RT . . . . . . . . . (1)

where

P = pressure

V = Volume

T= Temperature

n = Number of moles

R = ideal gas constant

where

R = 0.08206 L.atm / mol. K

Now put the value in formula (1) to calculate no. of moles of

              n = 1.2 atm x 0.0052 L / 0.08206 L.atm.mol⁻¹. K⁻¹ x 294.3 K

              n = 0.0062 atm.L / 24.162 L.atm.mol⁻¹

              n = 2.583 x 10⁻⁴ mol

no. of moles of gas (H₂) = 2.583 x 10⁻⁴ mol

a rain shadow is a dry region of land on the side that is protected against the prevailing winds of a mountain range. the prevailing winds are the winds that occur most of the time in a particular place of the earth

prevailing winds carry air toward the mountain range. as the air rises up over a mountain range, the air cools, water vapor condenses, and clouds form. on this side of the mountains, called the windward side, precipitation falls in the form of  rain  or snow. this dry air produces a  rain shadow.