
Consider the above reaction, what mass of CaCl₂ will be formed if 250 ml of 0.76 M HCl reacts with 1000 g of CaCO₃?
We are asked to calculate the mass of calcium chloride (\( \text{CaCl}_2 \)) formed from the reaction between 250 mL of 0.76 M hydrochloric acid (\( \text{HCl} \)) and 1000 g of calcium carbonate (\( \text{CaCO}_3 \)). The balanced chemical equation is provided.
This is a stoichiometry problem that involves a limiting reactant. The limiting reactant is the reactant that is completely consumed in a chemical reaction and therefore determines the maximum amount of product that can be formed.
The formula for moles from molarity and volume is: \( \text{Moles} = \text{Molarity} \times \text{Volume in Liters} \). The formula for moles from mass is: \( \text{Moles} = \frac{\text{Mass}}{\text{Molar Mass}} \).
Step 1: Calculate the molar masses of the reactants and the product.
Given molar masses: Ca = 40, C = 12, O = 16, Cl = 35.5 g/mol.
Step 2: Calculate the number of moles of each reactant.
For HCl:
\[ \text{Volume} = 250 \, \text{mL} = 0.250 \, \text{L} \] \[ \text{Molarity} = 0.76 \, \text{M} = 0.76 \, \text{mol/L} \] \[ \text{Moles of HCl} = 0.76 \, \frac{\text{mol}}{\text{L}} \times 0.250 \, \text{L} = 0.19 \, \text{mol} \]
For \( \text{CaCO}_3 \):
\[ \text{Mass} = 1000 \, \text{g} \] \[ \text{Molar Mass} = 100 \, \text{g/mol} \] \[ \text{Moles of } \text{CaCO}_3 = \frac{1000 \, \text{g}}{100 \, \text{g/mol}} = 10 \, \text{mol} \]
Step 3: Identify the limiting reactant.
The balanced chemical equation is: \( \text{CaCO}_3(s) + 2\text{HCl}(aq) \rightarrow \text{CaCl}_2(aq) + \text{CO}_2(g) + \text{H}_2\text{O}(l) \).
The stoichiometry shows that 1 mole of \( \text{CaCO}_3 \) reacts with 2 moles of \( \text{HCl} \).
Let's determine how many moles of \( \text{CaCO}_3 \) are required to react completely with the available \( \text{HCl} \):
\[ \text{Moles of } \text{CaCO}_3 \text{ needed} = 0.19 \, \text{mol HCl} \times \frac{1 \, \text{mol CaCO}_3}{2 \, \text{mol HCl}} = 0.095 \, \text{mol CaCO}_3 \]
We have 10 moles of \( \text{CaCO}_3 \) available, which is much more than the 0.095 moles needed. Therefore, \( \text{CaCO}_3 \) is in excess, and HCl is the limiting reactant.
Step 4: Calculate the moles of \( \text{CaCl}_2 \) formed.
The amount of product formed is determined by the limiting reactant (HCl). From the balanced equation, 2 moles of \( \text{HCl} \) produce 1 mole of \( \text{CaCl}_2 \).
\[ \text{Moles of } \text{CaCl}_2 = 0.19 \, \text{mol HCl} \times \frac{1 \, \text{mol CaCl}_2}{2 \, \text{mol HCl}} = 0.095 \, \text{mol CaCl}_2 \]
Step 5: Calculate the mass of \( \text{CaCl}_2 \) formed.
Using the molar mass of \( \text{CaCl}_2 \) calculated in Step 1:
\[ \text{Mass of } \text{CaCl}_2 = \text{Moles} \times \text{Molar Mass} \] \[ \text{Mass of } \text{CaCl}_2 = 0.095 \, \text{mol} \times 111 \, \text{g/mol} = 10.545 \, \text{g} \]
The mass of \( \text{CaCl}_2 \) formed will be 10.545 g.
What will be the equilibrium constant of the given reaction carried out in a \(5 \,L\) vessel and having equilibrium amounts of \(A_2\) and \(A\) as \(0.5\) mole and \(2 \times 10^{-6}\) mole respectively?
The reaction : \(A_2 \rightleftharpoons 2A\)

Cobalt chloride when dissolved in water forms pink colored complex $X$ which has octahedral geometry. This solution on treating with cone $HCl$ forms deep blue complex, $\underline{Y}$ which has a $\underline{Z}$ geometry $X, Y$ and $Z$, respectively, are
What will be the equilibrium constant of the given reaction carried out in a \(5 \,L\) vessel and having equilibrium amounts of \(A_2\) and \(A\) as \(0.5\) mole and \(2 \times 10^{-6}\) mole respectively?
The reaction : \(A_2 \rightleftharpoons 2A\)