ogen gas in a buret by displacing water at 260C The buret co

ogen gas in a buret by displacing water at 260°C. The buret could not be suh level in the water bath. The volume of the gas in the buret was determined to merged d above the water eep enough in a water bath to equalize the pressure. The water level in the buret was 14.1 be 33.6 f ns atmoepheric pressure was 753 torr, what is the pressure of the hydrogen in the buret? derey of H i 13.6/) (The b. How many moles of hydrogen did the student collect?

Solution

4. From the given data

Temperature (T) = 26 oC + 273 = 299 K

Volume of H2 = 33.6 ml = 0.0336 L

a. Vapor pressure of water at 26 oC = 25.2 torr

water level in the buret = 14.1 cm = 141 mm

atmospheric pressure = 753 torr

So,

Pressure of H2 gas (P) = 753 - (141/13.6) - 25.2 = 717.43 torr [using density]

In atm P = 717.43/760 = 0.944 atm

b. moles of H2 gas colledcted = PV/RT

R = gas constant

feeding values,

moles of H2 gas = 0.944 x 0.0336/0.08205 x 299 = 0.0013 mol