3. How many molecules are in 0.025 moles of CH4? 4. How many atoms are contained in 1.26 moles of Pb?

5. How many molecules are in 0.56 moles of CO2?

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Explanation:

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56 moles of   lieter in chemistry

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