A1.000 ml aliquot of a solution containing cu2+ and ni2+ is treated with 25.00 ml of a 0.04590 m edta solution. the solution is then back titrated with 0.02207 m zn2+ solution at a ph of 5. a volume of 21.73 ml of the zn2+ solution was needed to reach the xylenol orange end point. a 2.000 ml aliquot of the cu2+ and ni2+ solution is fed through an ion-exchange column that retains ni2+ . the cu2+ that passed through the column is treated with 25.00 ml of 0.04590 m edta . this solution required 24.47 ml of 0.02207 m zn2+ for back titration. the ni2+ extracted from the column was treated witn 25.00 ml of 0.04590 m edta . how many milliliters of 0.02207 m zn2+ is required for the back titration of the ni2+ solution?

the cold front replaces the warmer air at the ground level changing the wind to be breezy and denser.there is also an immediate drop in the temperature.

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

the answer is 0.42 is that is an option. this question provides no info