The GRESA method stands for:

• Given
• Required
• Equation
• Solution
• Answer

Let's apply this method to solve the problem:

1. GIVEN:

• Chemical reaction:
  $CaCO_3 + 2HCl \rightarrow CaCl_2 + H_2O + CO_2$
• Mass of CaCO₃ = 34.0 g
• HCl concentration = 0.80 M

2. REQUIRED:

Find the volume of 0.80 M HCl needed to dissolve the given amount of CaCO₃.

3. EQUATION:

We need to use the concept of stoichiometry to determine the amount of HCl required.

1. Calculate moles of CaCO₃ using its molar mass:
   $Molar\ mass\ of\ CaCO_3 = 40.08 + 12.01 + (3 \times 16.00) = 100.09\ g/mol$
   $\text{Moles of } CaCO_3 = \frac{\text{Mass}}{\text{Molar Mass}} = \frac{34.0\ g}{100.09\ g/mol}$
   $= 0.34\ mol$

2. Use the balanced equation to find moles of HCl needed:

   • From the equation: 1 mol of CaCO₃ reacts with 2 mol of HCl
   • So, 0.34 mol of CaCO₃ reacts with:
     $0.34 \times 2 = 0.68\ mol\ of\ HCl$

3. Find the volume of HCl solution required using molarity formula:
   $Molarity (M) = \frac{\text{Moles of solute}}{\text{Volume (L)}}$
   $Volume = \frac{\text{Moles of HCl}}{\text{Molarity}}$
   $= \frac{0.68\ mol}{0.80\ mol/L}$
   $= 0.85\ L = 850\ mL$

4. SOLUTION:

By following the stoichiometric steps, we determined that the volume of 0.80 M HCl required to dissolve 34.0 g of CaCO₃ is 850 mL.

5. ANSWER:

850 mL of 0.80 M HCl is needed to dissolve a 34.0 g CaCO₃ pearl.

Would you like a more detailed explanation for any step?

Related Questions:

1. What volume of 1.00 M HCl would be needed instead?
2. How much CO₂ gas is produced in this reaction?
3. What happens if an excess of HCl is added?
4. How would the required volume of HCl change if 17 g of CaCO₃ were used?
5. How does temperature affect the reaction rate?

Tip:

Always check the balanced chemical equation before performing stoichiometric calculations!