How does a 1:10 dilution differ from a 1:100 dilution?

How does a 1:10 dilution differ from a 1:100 dilution?

• A. A 1:10 dilution reduces concentration tenfold, while a 1:100 dilution reduces it a hundredfold.
• B. A 1:10 dilution increases concentration tenfold.
• C. They are the same dilution.
• D. A 1:100 dilution reduces it tenfold.

Answer: (A)

Dilution factors show how much the concentration is lowered when you add diluent. In a 1:10 dilution, you mix 1 part sample with 9 parts diluent, so the final mixture is 10 parts total and only 1 part is the original sample. That makes the concentration one-tenth of what it started with—tenfold lower (it leaves 10% of the original concentration). In a 1:100 dilution, you mix 1 part sample with 99 parts diluent, giving 100 parts total and only 1 part original. That reduces the concentration to one-hundredth of the starting concentration—a hundredfold lower (it leaves 1% of the original concentration). So the 1:10 dilution reduces concentration by a factor of 10, while the 1:100 dilution reduces it by a factor of 100.

Dilution factors show how much the concentration is lowered when you add diluent. In a 1:10 dilution, you mix 1 part sample with 9 parts diluent, so the final mixture is 10 parts total and only 1 part is the original sample. That makes the concentration one-tenth of what it started with—tenfold lower (it leaves 10% of the original concentration). In a 1:100 dilution, you mix 1 part sample with 99 parts diluent, giving 100 parts total and only 1 part original. That reduces the concentration to one-hundredth of the starting concentration—a hundredfold lower (it leaves 1% of the original concentration). So the 1:10 dilution reduces concentration by a factor of 10, while the 1:100 dilution reduces it by a factor of 100.