# Gases: Law of Combining Volumes (Worksheet)

## Q1

How many liters of ammonia gas is generated with 1 L of nitrogen gas reacts with 3 L of hydrogen gas via the following reaction (assuming no changing pressure and temperature):

$N_{2(g)} + 3H_{2(g)} \rightarrow 2NH_{3(g)}$

## Q2

How many liters of water vapor is generated after 2 L of hydrogen gas react with 1 L of oxygen gas (assuming no changing pressure and temperature)?

$2H_{2(g)} + O_{2(g)} \rightarrow 2H_2O_{(g)}$

## Q3

What is the theoretical volume of air required to completely burning 50 cubic meters of acetylene gas ($$C_2H_2$$) if the air contains 21% of oxygen (assuming no changing pressure and temperature)?

## Q4

In a combustion chamber containing 5 L of carbon monoxide and 2.5 L of oxygen is ignited at 298 K and 1 atmosphere pressure. Assuming complete combustion and no loss of gas, what will be the volume of carbon dioxide formed at 298 K and 1 atmosphere pressure?

## Q5

Consider the combustion reaction of hydrogen (assuming no changing pressure and temperature)::

$2H_{2(g)} + O_{2(g)} \rightarrow 2H_2O_{(g)}$

1. What volume of steam is formed from 50 cm3 of hydrogen and 50 cm3 of oxygen mixed together?
2. What gas(s) is in excess and by how much?

## Q6

What volume of propane $$C_3H_{6(g)}$$ reacts with $$100 \;cm^3$$ of oxygen used in the complete combustion reaction, assuming no changing pressure and temperature: (hint: construct the balanced combustion reaction).

$C_3H_{6(g)} + 5O+2 \rightarrow 3CO_2 + 4H-2O$

## Q7

Liquid water can be decomposed into hydrogen and oxygen under suitable conditions (e.g., electrolysis) via the balanced reaction:

$2H_2O_{(l)} \rightarrow 2H_{2(g)} + O_{2(g)}$

If an experiment generates 2500 cm3 of $$H_2$$ gas, what volume of $$O_2$$ is generated under the same conditions of temperature and pressure?