Twenty gallons of a salt solution consists of 35% salt. it is the result of mixing a 50% solution with a 25% solution. how many gallons of each of the solutions was used? let x= the number of gallons of the 50% solution and y= the number of gallons of the 25% solution. the corresponding modeling system is?

The volume of the 50% solution used is 0.8 gallons and the volume of 25% solution used is 1.2 gallons.

Explanation:

Let the volume of the 50% solution be be x gallons.

Let the volume of 25% solution be y gallons.

Total volume of the solution after mixing above volumes of the solutions = 2 gallons

x gal + y gal = 2 gal

...[1]

Percentage of the final salt solution = 35%

....[2]

On solving [1] and [2] , we get:

x = 0.8 , y = 1.2

So, the volume of the 50% solution used is 0.8 gallons and the volume of 25% solution used is 1.2 gallons.

answer: find it ur self

explanation:

answer : third trial had the contaminated sample and the correct value for dhrxn should be 1000 kj/mol

explanation :

let us write down the given equations

equation 1 :

equation 2 :

equation 3 :

let us use hess's law to find out which 2 equations can be added to get the third equation.

let us reverse equation 2 and multiply it by 2. the new equation that we get is,

equation 4 :

let us add equation 1 & 4

the above equation is similar to equation 3 but has different value for dhrxn.

therefore third trial had the contaminated sample and the correct value for dhrxn should be 1000 kj/mol