
Respuesta :
Answer:
Mass of CaClâ‚‚ produced = 15 g
Excess reactant = CaCO₃
Mass of CaCO₃ left = 11.5 g
Explanation:
Given data:
Mass of calcium carbonate = 25 g
Mass of hydrochloric acid = 10.0 g
Mass of calcium chloride produced = ?
Chemical equation:
CaCO₃ + 2HCl  → CaCl₂  + H₂O + CO₂
Number of moles of CaCO₃:
Number of moles of CaCO₃ = Mass /molar mass
Number of moles of CaCO₃= 25.0 g / 100.1 g/mol
Number of moles of CaCO₃ = 0.25 mol
Number of moles of HCl: Â
Number of moles of HCl = Mass /molar mass
Number of moles of HCl = 10.0 g / 36.5 g/mol
Number of moles of HCl = 0.27 mol
Now we will compare the moles of CaCl₂ with HCl and CaCO₃ .
         CaCO₃    :        CaCl₂
          1        :        1
         0.25      :       0.25
        HCl        :         CaCl₂
         2         :         1
         0.27       :        1/2 × 0.27 = 0.135 mol
The number of moles of CaClâ‚‚ produced by HCl are less it will be limiting reactant.
Mass of CaCl₂ = moles × molar mass
Mass of CaCl₂ =0.135 mol × 110.98 g/mol
Mass of CaClâ‚‚ = Â 15 g
The calcium carbonate is present in excess.
        HCl        :         CaCO₃
         2         :         1
         0.27       :        1/2 × 0.27 = 0.135 mol
So, 0.135 moles react with 0.27 moles of HCl.
The moles of CaCO₃ remain unreacted = 0.25 - 0.135
The moles of CaCO₃ remain unreacted = 0.115 mol
Mass remain unreacted:
Mass of of CaCO₃ remain unreacted = Moles × molar mass
Mass of of CaCO₃ remain unreacted = 0.115 mol × 100.1 g/mol
Mass of of CaCO₃ remain unreacted = 11.5 g