4. Quando se obtém a potência máxima da célula, o valor indicado no amperímetro, na unidade SI, está no intervalo: (A) [3,1; 3,2]. (B) [3,4; 3,5]. (C) [2,3; 2,4]. (D) [1 ...

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Explanation:

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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