When solid calcium carbonate is reacted with aqueous hydrochloric acid, the products of the reaction include aqueous calcium chloride, liquid water, and gaseous carbon dioxide. calculate the volume of co₂ gas collected over water at 25.0 °c when 25.1 g of calcium carbonate is added to excess hydrochloric acid if the total pressure is 911 mm hg. the vapor pressure of water at 25.0 °c is 23.8 mm hg.

V = 5.25 L

Explanation:

Vapor pressure of water = 23.8 mmHg

Total vapor pressure = 911 mmHg

Vapor pressure of carbon dioxide gas = Total vapor pressure - Vapor pressure of water = (911 - 23.8) mmHg = 887.2 mmHg

Mass of calcium carbonate = 25.1 g

Molar mass of = 100.0869 g/mol

The formula for the calculation of moles is shown below:

Thus,

Moles of = 0.2508 moles

From the reaction shown below as;

1 mole of calcium carbonate on reaction forms 1 mole of carbon dioxide

0.2508 mole of calcium carbonate on reaction forms 0.2508 mole of carbon dioxide

Mole of carbon dioxide = 0.2508 moles

We use the equation given by ideal gas which follows:

where,

P = pressure of the gas = 887.2 mmHg  

V = ?

T = Temperature of the gas =

R = Gas constant =

n = number of moles of carbon dioxide gas = 0.2508 moles

Putting values in above equation, we get:

V = 5.25 L

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