3. How many grams of oxygen are needed for the complete combustion of 11 grams of propane, C3H8?
C3H8 + 5 O2 + 3 CO2 + 4 H2O

Mass = 40 g

Explanation:

Given data:

Mass of oxygen needed = ?

Mass of propane = 11 g

Solution:

Chemical equation:

C₃H₈ +5O₂   →     3CO₂ + 4H₂O

Number of moles of propane:

Number of moles = mass/molar mass

Number of moles = 11 g/ 44.1 g/mol

Number of moles = 0.25 mol

now we will compare the moles of propane and oxygen.

              C₃H₈        :          O₂

                  1           :            5

                0.25      :            5/1×0.25 = 1.25 mol

Mass of oxygen needed:

Mass = number of moles × molar mass

Mass = 1.25 mol × 32 g/mol

Mass = 40 g

radioactive decay occurs in unstable atomic nuclei – that is, ones that don't have enough binding energy to hold

the nucleus together due to an excess of either protons or neutrons.

well in order to answer this question you have to provide more information < 3