Density = mass/volume = 80 g/10cm³ = 8 g/cm³
Let initially there are 10 molecules of O2 and 3 molecules of C3H8 present
The reaction will be
C3H8(g) + 5O2(g) ----> 3CO2(g) + 4H2O
so here oxygen molecules are limiting as for 3 molecules of C3H8 we need 15 molecules of O2
now the given 10 molecules of O2 will react with only 2 molecules of C3H8 and they will form six molecules of CO2 and 8 molecules of H2O
Hence answer is
molecules of CO2 formed = 6
Molecules of H2O formed = 8
molecules of C3H8 left = 1
molecules of O2 left = 0
Examination by a test; experiment, as in chemistry, metallurgy, etc.
Physical properties are properties that change form but not it's chemical compound
chemical properties are properties that change in chemical substance like burning tearing
C is the answer because he wants to know if less force is needed to pull on a slippery surface which reduces friction
