How many litres of concentrated 90% acid need to be mixed with 75% solution of concentrated acid to get a 3o litre soluton of concentrated acid

• how can we find the volume of solution when we don't noe the volume of either solvant..
• 12 years agoHelpfull: Yes(3) No(0)
• Funny answer,
  If 78 ltrs of one mixture is added , how will you get only 30 ltr of total mixture of unknown coceerntration ?
• 12 years agoHelpfull: Yes(3) No(1)
• 78 is answer
  
• 12 years agoHelpfull: Yes(1) No(8)
• rajesh.chaparala@gmail.com
• 12 years agoHelpfull: Yes(1) No(1)
• 7.5 liter
• 12 years agoHelpfull: Yes(0) No(1)
• RATIO 90%:75%=5:2 can be obained using alligations
  thus,150/7 of 90% needs to be mixed with 60/7 of 75%
• 11 years agoHelpfull: Yes(0) No(0)
• Answer: Op 3: 6L.
  Solution:
  It is a linear problem of 2 variables. suppose we mix x litres of 90% concentrated acid with y litres of 75% concentrated acid. Total we get 30 litres. Therefore,
  x + y = 30 ------------ equation (1)
  The resulting mixture has 78% concentrated acid, therefore, 78%*30 = 23.4 litres of acid.
  First solution has 90% acid, second has 75% acid, therefore,
  0.9x + 0.75y = 78%*30 = 23.4 ------------ equation (2)
  0.9x + 0.9 y = 0.9*30 = 27 ---------------- modified equation (1)
  subtracting equation 2 from equation 1,
  0.15y = 3.6. it follows that y = 24, i.e., 3.6/0.15
  Also x + y = 30, therefore x = 30 - y = 30 - 24 = 6.
• 10 years agoHelpfull: Yes(0) No(0)