Which piece of equipment would be BEST to measure 5 mL of a liquid? A 50 mL beaker filled half way between 0 and 10 mL markings A 50 mL Erlenmeyer flask filled half way between 0 and 10 ml markings A 10 mL graduated cylinder A disposable dropper A 100 mL graduated cylinder

Which piece of equipment would be BEST to measure 5 mL of a liquid?

A 50 mL beaker filled halfway between 0 and 10 mL markings

A 50 mL Erlenmeyer flask filled halfway between 0 and 10 ml marking

A 10 mL graduated cylinder

A disposable dropper

A 100 mL graduated cylinder

Explanation:

To measure 5 mL of a liquid, the best equipment is

a 10 mL graduated cylinder.

The remaining apparatus do not give an accurate measurement because readings are not marked on them.

the answer is 303.15 or 303

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