(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

16

explanation:

the marks go by 4s

answer: atomic mass was originally used to arrange elements on the periodic table, but is no longer used to organize the modern version.

explanation:

originally atomic mass was used to arrange elements on the periodic table from left to right in a row. each column then shows similar properties of elements of a group.

in modern periodic table, the atoms are arranged in increasing atomic number. as atomic number represents the number of protons in an atom which is unique for every atom.