Zn + 2HCl → ZnCl2 + H2
At conditions of Standard Temperature and Pressure, determine how many liters of hydrogen gas are produced by completely reacting a zinc nail with a mass of 2.2g with an excess of hydrochloric acid.
Question 3 options:
0.75L
6.42L
0.0015L
1.33L
To solve this problem, we need to use the molar ratio between zinc and hydrogen gas given by the balanced chemical equation.
1 mole of zinc (Zn) reacts with 2 moles of hydrochloric acid (HCl) to produce 1 mole of zinc chloride (ZnCl2) and 1 mole of hydrogen gas (H2).
First, we need to calculate the number of moles of zinc in 2.2g using its molar mass:
Molar mass of zinc (Zn) = 65.38 g/mol
Number of moles of zinc = mass of zinc / molar mass of zinc
Number of moles of zinc = 2.2g / 65.38 g/mol
Number of moles of zinc = 0.0336 mol
Since the reaction is 1:1 between zinc and hydrogen gas, the number of moles of hydrogen gas produced will also be 0.0336 mol.
Now we can use the ideal gas law to calculate the volume of the hydrogen gas at standard temperature and pressure (STP), which is 0°C or 273.15 K and 1 atm:
Ideal gas law: PV = nRT
Since we know the number of moles of hydrogen gas (n), the temperature (T), and the pressure (P), we can solve for the volume (V).
R is the ideal gas constant, which is 0.0821 L∙atm/mol∙K.
V = (nRT) / P
V = (0.0336 mol) * (0.0821 L∙atm/mol∙K) * (273.15 K) / (1 atm)
V ≈ 0.75 L
Therefore, approximately 0.75 L of hydrogen gas will be produced by the reaction. Thus, the correct answer is option 0.75L.