Consider the following exothermic equilibrium reaction. For each change, indicate whether it would cause the reaction to shift to the right (products), to the left (reactants), or have no effect. 4 HCl(g) + O2(g) ⟺ 2 H2O(l) + 2 Cl2(g)

Which way would the equilibrium shift if:
. the temperature is increased?
[ Select ]

2. HCl is added?
[ Select ]

3. Cl2 is removed?
[ Select ]

4. the temperature is decreased?
[ Select ]

5. Ne (neon) is added?

it is b that is the answer.

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