(i)what mass of carbon dioxide (in kg) is produced upon the complete combustion of

18.9 l of propane (approximate contents of one 5-gallon tank)? assume that the

density of the liquid propane in the tank is 0.621 g/ml . (hint: begin by writing

a balanced equation for the combustion reaction.)

m=? kg

(ii) a 22.0 - ml sample of an unknown h3po4 solution is titrated with a 0.110 m naoh

solution. the equivalence point is reached when 18.60 ml of naoh solution is added.

what is the concentration of the unknown h3po4 solution? the neutralization reaction is as

follows:

h3po4(aq) + 3naoh(aq) > 3h2o(l) + na3po4(aq)

m=?

The answer to your question is:

a) 35211 g of CO2

b) Molarity = 0.03

Explanation:

a)

mass of CO2 = ?

Volume = 18.9 L

density = 0.621 g/ml

Reaction

                C₃H₈    +    5O₂      ⇒     3CO₂     +     4H₂O

Density = mass / volume

mass = density x volume

mass = 0.621 x 18900

mass = 11737 g

MW of C3H8 = 44 g

MW of 3CO2 = 132 g

                         44 g of C3H8    132 g of CO2

                     11737 g of C3H8   x

                        x = (11737 x 132) / 44

                       x = 35211 g of CO2

b)             H3PO4(aq) + 3NaOH(aq) ---> 3H2O(l) + Na3PO4(aq)

                 22 ml             18.6 ml

                  [?]                  0.11 M

Calculate moles of NaOH

n = M x V

n = 0.11 x 0.0186

n = 0.0020 moles

From the balance reaction

               1 mol of H3PO4  3 moles of NaOH

                x                           0.0020 moles

               x = (0.002 x 1) / 3

              x = 0.0007  mol of H3PO4

Molarity = 0.0007 / 0.022

Molarity = 0.03

answer is a

explanation:

definition

                    entropy is a measure of the randomness or the extent of disorder of a chemical process.

                      enthalpy is a measure of the heat change of a reaction occurring at a constant pressure.

measurement units:

                        entropy is measured in joule per kelvin (jk⁻¹)   whereas enthalpy is measured in joule per mole (jmol⁻¹)

requirements:

                            entropy has no requirements or limits, and its change is measured by the division between the heat change of the chemical process and the temperature.

                              in contrast, enthalpy can only be related to the heat change of the reaction under standard conditions.