How many Joules must be removed to condense 150.0g of steam at 100.0 degrees Celsius to water at 100.0 degrees celcius

339kJ

Explanation:

Given parameters:

Mass of steam  = 150g  = 0.15kg

Initial temperature of steam  = 100°C

Final temperature of water  = 100°C  

Unknown:

Quantity of heat that must be removed to condense the steam = ?

Solution:

The heat involved here is a latent heat because there is no change temperature. The process is just a phase change.

  H  = mL

m is the mass

L is the latent heat of vaporization  = 2,260 kJ/kg

Insert the parameters and solve;

 H = 0.15kg x 2,260 kJ/kg

 H  = 339kJ

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