Wiki User
∙ 13y ago13.5 gallons
The 50% acid solution will contain 4.5 gallons of acid & 4.5 gallons of water.
So let X be the number of gallons of pure acid to add. You can set up an equation to solve for X:
(4.5 + X )
------------- = 0.80 (80% solution)
(9 + X)
The top part of the fraction is the amount of acid in the new 80% solution & the bottom part will be the total amount of solution you have. Cross multiply and solve for x.
(9+X)*(0.80) = (4.5+X)*(1)
7.2 + 0.8X = 4.5 + X
7.2 - 4.5 = 1X - 0.8X
2.7 = 0.2X
X = 2.7/0.2 = 13.5
Wiki User
∙ 13y ago25 gallons
x=45
50 gallons @ 3% must be added.
50% acid in a 6 gallon solution means that 3 gallons are acid. 9 gallons more acid will give you a total of 12 gallons of acid in a 15 gallon solution. 12 is 80% of 15.
x = 10% solution y = 35% solution .1x+.35y=.20*12 x+y=12 y=12-x .1x+.35(12-x)=.20*12 .1x+4.2-.35x=2.4 -.25x=-1.8 .25x=1.8 x=7.2 gallons y=4.8 gallons
25 gallons
x=45
50 gallons @ 3% must be added.
pH less than 7
50% acid in a 6 gallon solution means that 3 gallons are acid. 9 gallons more acid will give you a total of 12 gallons of acid in a 15 gallon solution. 12 is 80% of 15.
614
630
70gallons
Let x be the gallons of the 80% acid solution needed. The amount of acid in the 80% solution is 0.8x, and the amount in the 16% solution is 0.16*60=9.6. We want a total of (x+60) gallons of solution with 60% acid, so we have the equation 0.8x + 9.6 = 0.6(x+60). Solving for x gives x = 24 gallons.
Let x represent the amount of 12% solution and (10-x) represent the amount of 20% solution. The equation to solve is: 0.12x + 0.20(10-x) = 0.14(10). Solving for x gives x = 4, so you need 4 gallons of the 12% solution and 6 gallons of the 20% solution to make 10 gallons of the 14% solution.
Let x represent the gallons of 10% ammonia solution. The total volume of the mixture is x + 50 gallons. The equation for the mixture is: 0.10x + 0.30(50) = 0.15(x + 50). Solving this equation gives x = 50 gallons of the 10% ammonia solution needed.
x = 10% solution y = 35% solution .1x+.35y=.20*12 x+y=12 y=12-x .1x+.35(12-x)=.20*12 .1x+4.2-.35x=2.4 -.25x=-1.8 .25x=1.8 x=7.2 gallons y=4.8 gallons