What are the periodic trends of ionic radii? Check all that apply.

Ionic radii tend to increase down a group.

Ionic radii tend to decrease across a period.

Anionic radii tend to increase across a period.

Cationic radii tend to decrease across a period.

Ionic radii increase when switching from cations to anions in a period.

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

answeridentity;

the answer is a! (2.9 x 10^-18 j) hope i could someone. : )