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Chemistry LibreTexts

Gases: Law of Combining Volumes (Worksheet)

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  • 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):

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


    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)?

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


    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)?


    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?


    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?



    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).

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


    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?