Question 486546
How much pure hydrocloric acid must be added to 40 milliliters of a 50% solution to obtain a 75% acid solution?
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let x= milliliters of pure hydrocloric acid to be added 
100%(x)+50%(40)=75%(x+40)
x+20=.75x+30
.25x=10
x=10/.25=40
ans:
40 milliliters of pure hydrocloric acid must be added to 40 milliliters of a 50% solution to obtain a 75% acid solution?