Pure metals, metal carbonates, chlorides, and hydrochlorides react with acids producing gas. The amount of gas produced can be determined experimentally in the lab and converted into appropriate units of measurement.
Equations below shows chemical reactions that take place when the given chemical elements and compounds react with Hydrochloric acid.
Caco3(s) +2 Cacl2(s) + CO2 (g) +H2O (l)
+ CO2 (g) + H2O (l)
Cl2(s) + H2 (g)
From the ideal gas laws, it is possible to measure the volume of a gas produced in a given condition of pressure and temperature. The volume of gas can be determined from the ideal gas law equation , where R is the gas constant. All units of measurement must be in standard form for the law to apply (Castellan, 1971). Thus, temperature measurement is in Kelvin, volume units measured in liters and pressures measured in atmospheres. Pressure sensor determines the gas pressure.
Gas Stoichiometry Calculations
The provided pressure probes read the change of pressure in air tight cylinder. Consider the reaction of magnesium with hydrochloric acid. From the balanced equation, number of moles of the gas produced can be determined using the mole ratio. For, example using 0.2 grams of magnesium, we calculate the number of moles by dividing mass by its relative molecular mass. Thus, . From the equation, one mole of magnesium produces one mole of hydrogen gas. The reaction requires two moles of the acid. The volume of the acid required is determined by multiplying the number of moles with its molecular mass. In addition, we take the number of moles of hydrogen to be the same as that of magnesium. Applying the gas law equation, from which we simply take the values of read temperature and pressure and substitute to get the volume of the gas produced.