Yield (chemistry) facts for kids
In chemistry, yield is a super important idea! It tells us how much of a new substance, called a product, we get from a chemical reaction. Think of it like baking a cake: the yield would be how much cake you actually end up with after mixing and baking all your ingredients.
We can talk about yield in a few ways:
- Absolute yield tells us the exact weight of the product, usually in grams.
- Molar yield tells us how many moles of the product we have. A mole is just a way chemists count very tiny particles.
What is Percentage Yield?
The percentage yield is a special number that shows how well a chemical experiment worked. It compares how much product you actually made to how much you could have made if everything went perfectly.
To figure out the percentage yield, we use a simple calculation:
- First, find the fractional yield. This is the amount of product you actually got (the "actual yield") divided by the most product you could possibly get (the "theoretical yield"). Both amounts must be measured in the same way (like grams or moles).
- Then, to turn this into a percentage yield, you just multiply the fractional yield by 100%. For example, if your fractional yield is 0.673, your percentage yield is 67.3%.
Why Isn't Yield Always 100%?
In a perfect world, every chemical reaction would have a 100% yield. This would mean you got every single bit of product you expected! However, in real life, it's almost impossible to get a 100% yield. This is because:
- Measurements are never perfectly exact.
- Some product might be lost during the experiment (like sticking to the equipment).
- Other unwanted reactions might happen.
Chemists use different words to describe how good a yield is:
- Quantitative means the yield is around 100%.
- Excellent means the yield is more than 90%.
- Very good means the yield is more than 80%.
- Good means the yield is more than 70%.
- Fair means the yield is more than 50%.
- Poor means the yield is less than 40%.
See also
- In Spanish: Rendimiento químico para niños
Images for kids
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A robot helping with chemistry experiments.
