A piece of zinc was added to 1000 cm3 of 0.2M hydrochloric acid. After effervescence had stopped. 28 cm3 of the resulting solution required 17 cm3 of sodium trioxocarbonate IV solution for complete neutralization. Calculate the mass of zinc added.?
To calculate the mass of zinc added, we need to use stoichiometry and the concept of limiting reactants.
Here's the step-by-step explanation:
Step 1: Write the balanced chemical equation for the reaction between zinc and hydrochloric acid.
Zn(s) + 2HCl(aq) → ZnCl2(aq) + H2(g)
Step 2: Determine the moles of sodium trioxocarbonate IV solution (Na2CO3) used.
From the balanced equation, we can see that 2 moles of HCl react with 1 mole of Na2CO3. Therefore, the moles of Na2CO3 used is:
Moles of Na2CO3 = Volume of Na2CO3 solution (in dm3) × Molarity of Na2CO3
Given: Volume of Na2CO3 solution = 17 cm3 = 17/1000 dm3 (convert to dm3)
Molarity of Na2CO3 = Unknown
Step 3: Determine the concentration of the sodium trioxocarbonate IV solution.
To do this, we use the known concentration of hydrochloric acid and the stoichiometry of the reaction between hydrochloric acid and sodium trioxocarbonate IV.
From the balanced equation, we can see that 2 moles of HCl react with 1 mole of Na2CO3. Therefore, the molar concentration of Na2CO3 can be calculated as follows:
Molarity of Na2CO3 = (0.2 M HCl × 2) / 1
Step 4: Calculate the moles of Na2CO3 used.
Substituting the values into the formula:
Moles of Na2CO3 = (17/1000 dm3) × (0.2 M HCl × 2) / 1
Step 5: Determine the moles of zinc used.
From the balanced equation, we can see that 2 moles of HCl react with 1 mole of zinc. Therefore, the moles of zinc used can be calculated as follows:
Moles of zinc = Moles of Na2CO3 / 2
Step 6: Calculate the mass of zinc added.
To calculate the mass of zinc, we need to use its molar mass:
Molar mass of zinc (Zn) = 65.38 g/mol (from periodic table)
Mass of zinc = Moles of zinc × Molar mass of zinc
Substitute the values into the formula:
Mass of zinc = (Moles of Na2CO3 / 2) × 65.38 g/mol
Now, you can perform the calculations to determine the mass of zinc added.