What volume of hydrogen is collected if the ext pressure is 754 mmHg &the temperature is 30∘C assuming that there is no water vapor present?

A 14.74-g aluminum soda can reacts with hydrochloric acid according to the reaction:

2Al(s)+6HCl(aq)→3H2+2AlCl3(aq)

The hydrogen gas is collected by the displacement of water.

What volume of hydrogen is collected if the ext pressure is 754 mmHg &the temperature is 30∘C assuming that there is no water vapor present?

What is the vapor pressure of water at this temperature?

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  • 1 month ago

    2 Al + 6 HCl → 3 H2 + 2 AlCl3

    Supposing there is an excess of HCl:

    (14.74 g Al) / (26.98154 g Al/mol) x (3 mol H2 / 2 mol Al) = 0.81945 mol

    Supposing there is no water vapor (ignoring the statement "The hydrogen gas is collected by the displacement of water."):

    V = nRT / P = (0.81945 mol) x (62.36367 L mmHg/K mol) x (30 + 273) K /

    (754 mmHg) = 20.5 L

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    The vapor pressure of water at 30°C is 31.8 torr.

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