Theoretical and percent yield
Grade 10 Science Worksheet - Building Confidence
Circle the best answer, or write your answer on the line.
Baking soda and vinegar should give 4.4 g of CO₂, but 3.96 g is collected. What is the percent yield, to 0.1%, Ari?
A reaction should give 8.8 g of CO₂, and 7.48 g is collected. What is the percent yield, to 0.1%, Bo?
A class works out that 4.40 g of CO₂ should form, then weighs 3.96 g. Which is the theoretical yield, Jun?
- 8.36 g, the two added together
- 3.96 g, the amount weighed
- 4.40 g, the amount worked out from the equation
Which is the actual yield, Luz?
- The mass worked out from the balanced equation
- The mass of reactants weighed at the start
- The mass of product weighed at the end
In percent yield = actual ÷ theoretical × 100, which goes on top, Milo?
- The theoretical yield, what was expected
- Whichever of the two is larger
- The actual yield, what was made
A reaction has a 90% yield. What does that mean, Noah?
- 90% of the reactants turned into gas
- 10% of the atoms were destroyed
- 90% of the expected product was made
A class reports a 112% yield of dried crystals that were still damp. What does that suggest, Pia?
- The class made more product than possible, a great result
- New atoms formed during drying
- Water is still in the crystals, adding mass
Why is a percent yield usually less than 100%, Ren?
- Some product is lost or never forms
- Some atoms are destroyed in each reaction
- Yields above 100% are the normal result
A reaction is stopped before it finishes. How does that affect the yield, Zee?
- The yield goes up, since less is wasted
- The missing mass is destroyed
- Less product forms, so the yield falls
Some CO₂ bubbles escape before they are collected. Why is the yield lower, Esme?
- The escaped CO₂ was not weighed
- The escaped CO₂ was destroyed
- Escaped gas raises the percent yield