A conical flask has a volume of 71.9 mL. It is filled with water vapour at a pressure of 1053.8 kPa and a temperature of 738 K. Determine the mass of
water in the conical flask.
Select one:
O a. 0.363 g
O b.0.183 g
O c.0.129 g
O d. 0.222 g

d. 0.222 g

Explanation:

Given parameters:

volume of water  = 71.9mL  = 0.0719L

pressure  = 1053.8kPa = 10.4atm

temperature  = 738K

Unknown:

mass of water  = ?

Solution:

To find the mass of water, we need to obtain the number of moles from the given parameters.

This can be done using the ideal gas law;

              PV  = nRT

where P is the pressure

          V is the volume

           n is the number of moles

           R is the gas constant

           T is the temperature

     Input the parameters to find n;

          10.4 x 0.0719  = n x 0.082 x 738

                  n  = 0.012moles

Mass of water vapor  = number of moles x molar mass

          molar mass of H₂O  = 2 + 16  = 18g/mol

Mass of water vapor  = 0.012 x 18 = 0.22g

answer : one can design an experiment using a liquid and an additive that can be added to the liquid and observe the chemical changes in the reaction species.

one would need a beaker which is filled with a known amount of the liquid in which thermometer is placed to measure the temperature changes; after addition of the additive to the liquid solution one can note down the temperature change and find whether the reaction is endothermic or exothermic in nature. by subtracting the initial temperature value with the final temperature one can find the temperature changes.

various combinations of liquid and additive can be used. liquid in this case can be a known quantity of water and additives can be epsom salt or without epsom salt the experiment can be conducted to notice the changes. water and ice, hydrogen peroxide and dry yeast, vinegar and baking soda,etc.