How many moles of neon gas are there if 25.0 liters of the gas are at 5.0°C with a
pressure of 89.9 kPa?

0.98mole

Explanation:

Data obtained from the question include:

V (volume) = 25L

T (temperature) = 5.0°C = 5 + 273 = 278K

P (pressure) = 89.9 kPa

Recall: 1kPa = 1000Pa

89.9 kPa = 89.9 x 1000 = 89900Pa

But: 101325Pa = 1atm

Therefore, 89900Pa = 89900/101325 = 0.89atm

R (gas constant) = 0.082atm.L/Kmol

n (number of mole) =?

Using the ideal gas equation PV = nRT, we can obtain the number of mole of Neon gas as shown below:

PV = nRT

n = PV /RT

n = (0.89x25)/(0.082x278)

n = 0.98mole

Therefore, the number of mole of Neon gas present is 0.98mole

c- cold periods in earth's history during which glaciers covered much of the surface.

explanation:

8 m/s because for him to get the same amount of energy as ray is putting out, bobby, who weighs half as much as ray, needs to run twice as fast.