lab quiz limiting reactants and percent yield

1. What is a precipitation reaction?

A reaction where two aqueous solutions form a solid product.

What is a precipitate?

A solid that forms out of a solution.

What solid (precipitate) is made in this lab?

Calcium carbonate (CaCO₃), also called chalk.

Write the word equation for the chalk reaction

Calcium chloride + potassium carbonate → calcium carbonate + potassium chloride

Which product stays dissolved in water?

Potassium chloride (KCl).

Why does calcium carbonate form a solid?

Most metal carbonates are insoluble in water.

What is a limiting reactant?

The reactant that runs out first and limits product formation.

How do you identify the limiting reactant?

It produces the least amount of product.

What information do you need to find the limiting reactant?

The balanced equation and the moles of each reactant.

Why can’t chalk form if one reactant is missing?

Both reactants are required to make the product.

What is theoretical yield?

the amount obtained from calculations.

Is theoretical yield measured or calculated?

Calculated.

What is actual yield?

The amount of product actually made in the lab.

Is actual yield usually higher or lower than theoretical yield?

Lower.

Write the percent yield formula.

% Yield = (actual yield ÷ theoretical yield) × 100

What does percent yield measure?

The efficiency of the experiment.

Why is percent yield rarely 100%?

Product loss during transfers, filtering, or handling.

What percent yield is expected in this lab?

Greater than 80%.

Which safety equipment must be worn?

Safety goggles.

What should you do after the lab?

Wash hands with soap and water.