In an experiment to determine the universal gas constant
CHEMISTRY · Multi-part · A Level · Chemistry · Amount of substance · Amount of substance
Problem
In an experiment to determine the universal gas constant, a 500 mL rigid flask is filled with dry oxygen gas of mass 0.96 g. The gas exerts a pressure of 1.40 atm when the temperature is 35 °C.
Take molar mass of oxygen = 32 g mol⁻¹ and 1 atm = 1.013 × 10^5 Pa.
(i) Compute the number of moles of oxygen contained in the flask.
(ii) Using the data provided, calculate the value of the universal gas constant R obtained in this experiment. Express the result in J mol⁻¹ K⁻¹.
(iii) The accepted value of R is 8.314 J mol⁻¹ K⁻¹. Determine the percentage error of the experimentally obtained value.
(iv) Suggest two possible experimental factors that might account for the discrepancy between the experimental and accepted values.