Achemist adds 180.0 ml of a 1.42m sodium carbonate (na co,) solution to a reaction flask. calculate the millimoles of sodium carbonate the chemist has added to the flask. round your answer to 3 significant digits. mmol

The millimoles of sodium carbonate the chemist has added to the flask are 256

Explanation:

Molarity is defined as the number of moles dissolved per liter of the solution.

To calculate the number of moles for given molarity, we use the equation:

    .....(1)

Molarity of solution = 1.42 M

Volume of solution = 180.0 mL

Putting values in equation 1, we get:

Thus the millimoles of sodium carbonate the chemist has added to the flask are 256.

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