Question

In order to determine the rate of photosynthesis (the conversion by plants of carbon dioxide and water into glucose and oxygen), the oxygen gas emitted by an aquatic plant is collected over water at a temperature of 293 KK and a total pressure of 753.3 mmHg. Over a specific time-period, a total of 1.84 LL of gas is collected. The partial pressure of water at 293 KK is 17.55 mmHg. What mass of oxygen gas (in grams) forms?

Answer 1

Pressure of O2 = 753.3 - 17.55 = 735.75 mmHg

                         = 0.968 atm

T = 293 K

V = 1.84 L

P V = n R T

0.968 x 1.84 = n x 0.0821 x 293

n = 0.074050

mass of O2 = moles x molar mass

                   = 0.074050 x 32

                   = 2.37 g

mass of O2 = 2.37 g