Calorimetry Lab Report

MODULE 2

WORKSHEET

6

CALCULATIONS
INVOLVING GASES
Syllabus reference 9.3.2
1

Two identical gas flasks, A and B, are kept at the same temperature and pressure. Flask A contains
10 g of ethane gas, C2H6. Flask B contains sulfur dioxide gas, SO2. Calculate the mass of sulfur dioxide gas in flask B. moles ethane  10/30  0.33 mol moles SO2  0.33 mol mass SO2  0.33  64  21 g

2

What mass of nitric oxide, NO, is present in a 2.5 L flask at a pressure of 100 kPa and 0ºC? mole NO  2.5/22.71  0.1101 mol mass NO  0.1101  30  3.3 g

3

Carbon monoxide burns in oxygen according to the equation:
2CO(g)  O2(g) → 2CO2(g)
Calculate the volume of oxygen required at 25°C and 100 kPa for the combustion of 28 g of carbon monoxide. moles CO  28/28  1 mol
a Write a balanced equation for the reaction.
C2H5OH(l)  3O2(g) → 2CO2(g)  3H2O(l) b If 98 L of CO2 is formed at 25°C and 100 kPa, calculate the mass of ethanol used in the reaction. moles CO2  98/24.79  3.95 mol moles ethanol  3.95/2  1.98 mol mass ethanol 1.98  46  91 g

c

Use the data from part b to calculate the volume of liquid water formed when the products are condensed at 25°C and 100 kPa. moles water  3.95  3/2  5.925 mol volume water  5.925  18  107 mL

5

It has been estimated that 1  108 tonne of H2S gas is released annually into the atmosphere from biological sources. This H2S is oxidised to SO2 according to the