Mixture Problems
1. Your chemistry teacher asks you to mix 20% acid solution with 50% acid solution to obtain 12 ounces of 30% acid solution. How much of each must you use?
2. A metal alloy is 25% copper. Another metal alloy is 50% copper. How much of each alloy should be used to make 1000 grams of metal alloy that is 45% copper.
3. How many pounds of cashews worth 75 cents a pound must be mixed with pecans worth $1.50 a pound to obtain 50 pounds of mixed nuts worth $1.00 a pound?
4. How many grams of 55% acid solution must be added to 20 grams of 10% solution to produce a 50% acid solution?
5. How much pure alcohol must be added to 10 gallons of 35% alcohol to have a solution that is 60% alcohol?
6. How many grams of 80% hydrochloric acid solution must be added to 40 grams of 15% hydrochloric acid solution to produce a 40% acid solution?
7. How much of a 10% saline solution should be mixed with a 20% saline solution to obtain 1000 milliliters of a 12% saline solution?
8. Coffee worth $2.95 a pound was mixed with coffee worth $3.50 a pound to produce a blend worth $3.30 a pound. How much of each kind of coffee was used to produce 44 pounds of blended coffee?
9. A beaker of alcohol contains a solution that is 30% alcohol. In another beaker is a solution that is 50% alcohol. How much of each can be added to obtain 40L of a solution that is 45% alcohol?
10. Antifreeze A is 18% alcohol; antifreeze B is 10% alcohol. How many liters of each should be mixed in order to get 20 L of a mixture that is 15% alcohol?
11. How much pure alcohol must be added to 3 gallons of 12% solution to make a 28% solution?
12. Dried apricots worth $5.75 a pound were mixed with dried prunes worth $3.80 a pound to produce a mixture of dried fruit worth $4.25 a pound. How much of each kind of fruit was used to produce 52 pounds of mixture?
13. Soybean meal is 16% protein; cornmeal is 9% protein. How many pounds of each should be mixed together in order to get a 350-lb mixture that is 12%?
14. A chemist has one solution that is 25% boric acid and a second that is 50% boric acid. How many liters of each should be mixed together in order to get 10L of a solution that is 40% boric acid?
15. An automobile radiator holds 4 gallons of 25% antifreeze. How much of this must be drained out and replaced with water to make a 20% antifreeze solution?