During photosynthesis, water (H2O) and carbon dioxide (CO2) are combined to make glucose (C6H12O6) and oxygen (O2). Which equation is balanced? A) 6H2O + 6CO2 → C6H12O6 + 6O2
B)10H2O + 5CO2 → C6H12O6 + 15O2
C) 12H2O + 3CO2 → C6H12O6 + O2
D) H2O + CO2 → C6H12O6 + O2

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