Calculate the volumeof 1.0M NaOH necessary to completely neutralize 100mL of 0.50M of phosphoric acid (H3PO4)?

50 mL

Explanation:

In case of titration , the following formula is used -

M₁V₁ = M₂V₂

where ,

M₁ = concentration of acid ,

V₁ = volume of acid ,

M₂ = concentration of base,

V₂ = volume of base .

from , the question ,

M₁ =  0.50M

V₁ = 100 mL

M₂ =  1.0M

V₂ = ?

Using the above formula , the volume of base , can be calculated as ,

M₁V₁ = M₂V₂

substituting the respective values ,

0.50M * 100 mL =  1.0M * V₂  

V₂  = 50 mL

the answer is c i believe

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