Enter your answer in the provided box. On a certain winter day in Utah, the average atmospheric pressure is 718 torr. What is the molar density (in mol/L) of the air if the temperature is −29°C?

The correct answer is 0.047 mol/L

Explanation:

The atmospheric air is a mixture of gases. We can assume an ideal behavior of the gas and use the ideal gas equation:

PV= nRT

where P is the pressure, V is the volume, n is the number of moles, R is a constant (0.082 L.atm/K.mol) and T is the temperature in K.

We have to first convert the pressure from Torr to atm:

760 Torr= 1 atm

⇒ 718 Torr x 1 atm/760 Torr = 0.945 atm

Then, we convert the temperature from ºC to K:

0ºC = 273 K

⇒ -29ºC+273= 244 K

Finally, we introduce the data in the equation and calculate de densitiy, which is the moles per liters of gas (n/V):

PV = nRT

n/V= P/RT

n/V = (0.945 atm)/(0.082 L.atm/K.mol x 244 K) = 0.047 mol/L

the answer is b because, investigating whether another species of moth also drinks tears might be interesting, but it would not directly explain why this species of moth does.

to explain why this species of moth drinks tears, the scientist could ask: "what nutrients that moths need are in elephant tears? "

the scientist could experiment with moth repellent or oter ways to keep the moths away, but that would not answer his original question.