# What is the mass of iron that took part in the reaction and the percentage of iron in the alloy in the following case:Silicon steel is an alloy of the elements iron, carbon and silicon. An alloy...

What is the mass of iron that took part in the reaction and the percentage of iron in the alloy in the following case:

Silicon steel is an alloy of the elements iron, carbon and silicon. An alloy sample was reacted with excess hydrochloric acid and the following reaction occurred:

Fe (s) + 2HCl (aq) ---> FeCl2 (aq) + H2 (g)

The carbon and silicon in the alloy did not react with the acid. If an alloy sample with a mass of 0.160 g produced 62.0 mL of hydrogen gas, measured at SLC, calculate the mass of iron that reacted to produce this amount of hydrogen where the amount of hydrogen evolved in the reaction is 2.53 x 10^-3 mol as well as the percentage of iron in the alloy.

justaguide | College Teacher | (Level 2) Distinguished Educator

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An alloy of iron, carbon and silicon is reacted with excess hydrochloric acid and the following reaction occurred:

Fe (s) + 2HCl (aq) ---> FeCl2 (aq) + H2 (g)

The mass of the alloy sample that takes part in the reaction is 0.160 g. The reaction results in the formation of 2.53*10^-3 moles of hydrogen. From the equation it is seen that 1 mole of iron results in the formation of 1 mole of hydrogen gas. The molar mass of iron is 56 g/mol while that of hydrogen gas is 2 g/mol. To produce 2.53*10^-3 moles of hydrogen, 1.265 moles of iron is required. The mass of this amount of iron is 70.84*10^-3 g.

As the silicon and the carbon in the alloy does not react with the acid, the percentage of iron in the allow is 70.84*10^-3/0.16 = 44.275%

The mass of iron that reacted to produce 2.53*10^-3 moles of hydrogen is 70.84*10^-3 g. The percentage of iron in the alloy is 44.275%