Asmall amount of acid is added to a buffer solution, the ph of the solution will a. increase b. decrease c. stay about the same d. become neutral

A small amount of acid is added to a buffer solution, the ph of the solution will

A. increase

B. decrease  

C. stay about the same

D. become neutral

correct option is option C

Buffer is a solution which can resist the change in pH with small addition of acid or base.

Hence a small amount of acid when added to a buffer solution will not change its pH,or its pH remains the same.

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