An adult human lung has a volume of 2.9 liters. if its volume decreases to 1.2 liters and it contains 0.049 mole of air after it exhales, how many moles of air does it contain when full? a. 0.025 mol b. 0.041 mol c. 0.083 mol d. 0.12 mol e. 0.14 mol

D. 0.12

Explanation

- The lung contains 0.12 moles of air when it's full.

Solution:- At constant temperature and pressure, the volume is directly proportional to the moles of the gas.

where, and are the initial and final volumes. Similarly, and are the initial and final moles of the air.

Let's plug in the given values in the formula and solve this for initial moles of the gas.

So, the lung contains 0.12 moles of air when it's full.

"you start with 15.67 g mgco3-xh2o, when heated and all the water is removed, you are left with 7.58 g mgco3 only.

therefore, you had 15.67 - 7.58 = 8.09g h2o  

moles of each :

7.58g mgco3 = ? moles = 7.58g / 83.4g/mole = 0.09moles  

8 09g h2o = ? moles = 8.09g / 18g/mole = 0.44moles  

molar ratio between the two by dividing both numbers by the smallest number :

0.09 / 0.09 = 1  

0.44 / 0.09 = 4.8  

mgco3-5h2o"