22 400 ml of oxygen gas contains 6.022 1023 oxygen molecules at 0°c and standard atmospheric pressure. a. how many oxygen molecules are in 0.100 ml of gas? b. how many oxygen molecules are in 1.00 l of gas? c. what is the average space in milliters occupied by one oxygen molecule?

Answer :

(a) The number of oxygen molecules present in 0.100 mL of gas is,

(b) The number of oxygen molecules present in 1.0 L of gas is,

(c) The volume of oxygen gas is,

Explanation :

(a) To calculate the number of oxygen molecules present in 0.100 mL of gas.

As, 22400 mL of oxygen gas contains number of oxygen molecules

So, 0.100 mL of oxygen gas contains number of oxygen molecules

(b) To calculate the number of oxygen molecules present in 1.00 L or 1000 mL of gas.

As, 22400 mL of oxygen gas contains number of oxygen molecules

So, 1000 mL of oxygen gas contains number of oxygen molecules

(c) To calculate the volume of oxygen gas for one molecule of oxygen.

As, number of oxygen molecules present in 22400 mL of oxygen gas

So, 1 oxygen molecules present in of oxygen gas

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