Hydrochloric acid has the chemical formula hcl. a certain quantity of hydrochloric acid has 2.39x1024 atoms. how many moles of hydrochloric acid is the sample?

3.97 moles HCl

Explanation: Solution:

2.39x10²⁴ atoms HCl x 1 mole HCl /

6.022x10²³ atoms HCl

= 3.97 moles HCl

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