Question

Some iron wire weighing 22.38 g is placed in a beaker and covered with 60.0 g of dilute HCl. The acid reacts with the iron wire and gives off hydrogen gas, which escapes into the surrounding air, as well as products that remain in the beaker. After the reaction, the contents of the beaker weigh 81.6 g. What is the mass of the hydrogen gas produced by the reaction? Use significant figures!

Answer 1

The mass of hydrogen gas produced in the reaction is 0.78 g, which is calculated using the difference between the initial mass of reactants and the final mass of products, taking into account significant figures.

Step-by-step explanation:

To calculate the mass of hydrogen gas produced by the reaction, we use the mass of the reactants and products before and after the reaction. Initially, the mass of iron wire and hydrochloric acid is the sum of their individual masses, which is 22.38 g (iron) + 60.0 g (HCl) = 82.38 g. After the reaction, the beaker contents weigh 81.6 g. The mass of the hydrogen gas that escaped can be calculated by subtracting the final beaker mass from the initial total mass.

The equation for the mass of hydrogen gas is:

Mass of reactants (before) - Mass of products (after) = Mass of hydrogen gas

Therefore, the mass of hydrogen gas produced is:

82.38 g (initial mass) - 81.6 g (final mass) = 0.78 g

Using significant figures, the mass of hydrogen gas is reported as 0.78 g, since the least number of decimal places in the masses given is two.