Using the ideal gas equation, determine the number of moles present in a gas if it has a pressure of 2.35 atm, a volume of 1.49 L and a temperature of 40.2 oC. Enter your answer in standard notation.

n=PV/RT change temp to kelvins. Choose the right R constant for the units given

To determine the number of moles present in a gas using the ideal gas equation, we'll need to use the formula:

PV = nRT

Where:
P = Pressure (in atm)
V = Volume (in liters)
n = Number of moles
R = Ideal gas constant (0.0821 L·atm/mol·K)
T = Temperature (in Kelvin)

First, we need to convert the given temperature from Celsius to Kelvin:
T(K) = T(°C) + 273.15
T(K) = 40.2°C + 273.15 = 313.35 K

Now we can substitute the values we have into the ideal gas equation:

(2.35 atm)(1.49 L) = n(0.0821 L·atm/mol·K)(313.35 K)

Simplifying the equation:
3.49715 = 25.680135n

Dividing both sides by 25.680135:
n ≈ 0.136 moles

Therefore, the number of moles present in the gas is approximately 0.136 moles.