Pearson Edexcel IAL Chemistry 1.8 Gas volume calculations
Practise converting between moles and gas volumes using r.t.p. molar volume, stoichiometry and pV = nRT with correct units.
- Syllabus
- First assessment 2019
- Course
- Chemistry YCH11
- Level
- AS
Practise converting between moles and gas volumes using r.t.p. molar volume, stoichiometry and pV = nRT with correct units.
This question is about alkenes.
Bisabolenes are a group of compounds found in plants and fungi. Bisabolene molecules contain several carbon-carbon double bonds.
5.51 g of α-bisabolene reacted with 1873 cm3 of hydrogen gas, H2. The reaction occured at a temperature of 150∘C and a pressure of 152000 Pa .
[Mr value: α-bisabolene =204.0]
Calculate the amount, in mol, of hydrogen gas that reacted with α-bisabolene. Use the ideal gas equation, p V=n R T.
rearrangement of ideal gas equation (1)
- conversion of temperature and volume to appropriate units
(1)
- calculation of moles of hydrogen (1)
Example of calculation
n=p V / R T
M1 may be subsumed in M3
423( K), 1873 x 10^-6( m^3)
Allow 423( K), 1873 x 10^-3(dm^3), 152(kPa)
Allow 423.15 K (which gives final answer of 0.080963)
aligned
& =(152 x 10^3) x (1873 x 10^-6)8.31 x 423
& =0.080992 / 0.08099 / 0.0810 / 0.081( mol)
aligned
Correct answer with no working scores 1
Allow TE from M2 to M3
Ignore SF except 1SF
Penalise use of 1 SF once only in (c)(i) and (c)(ii)