Question 8.9: Dinitrogen oxide, N2O, which is used in dentistry, is an ane......
Dinitrogen oxide, N_{2}O, which is used in dentistry, is an anesthetic called laughing gas. What is the pressure, in atmospheres, of 0.350 mole of N_{2}O gas at 22 °C in a 5.00-L container?
STEP 1 State the given and needed quantities. When three of the four quantities (P, V, n, and T) are known, we use the ideal gas law equation to solve for the unknown quantity. It is helpful to organize the data in a table. The temperature is converted from degrees Celsius to kelvins so that the units of V, n, and T match the unit of the gas constant, R.
Table 1
STEP 2 Rearrange the ideal gas law equation to solve for the needed quantity. By dividing both sides of the ideal gas law equation by V, we solve for pressure, P.
PV=nRT Ideal gas law equation
\frac{P\cancel V}{\cancel V}=\frac {nRT}{V}
P=\frac{nRT}{V}
STEP 3 Substitute the gas data into the equation, and calculate the needed quantity.
P=\frac{0.350 \space \cancel{mole} \space \times \space \frac{0.0821 \space \cancel L · atm}{\cancel {mole} · \cancel K} \space \times \space 295 \space \cancel K}{5.00 \space \cancel L}=1.70 \space atm
Table 1 :
| ANALYZE THE PROBLEM |
Given | Need | Connect |
| V = 5.00 L n = 0.350 mole T = 22 °C + 273 = 295 K |
P | ideal gas law, PV = nRT R=\frac{0.0821 \space L \cdot atm}{mole \cdot K} |