The combustion of propane may be described by the chemical equation C3H8(g)+5O2(g)⟶3CO2(g)+4H2O(g) How many grams of O2(g) are needed to completely burn 56.3 g C3H8(g)?

204.7 g

Explanation:

(taking the atomic mass of C, H, O as 12, 1 and 16 respectively).

no. of moles of C3H8 burnt =  56.3 / (12x3 + 1x8)

                                              = 1.27955 mol

From the equation, the mole ratio of C3H8 :  O2 = 1:5

Hence,

the no. of moles of O2 required will be

=1.27955 x 5

= 6.397727 mol

Mass of O2 required = 6.397727 x (16x2)

= 204.7 g

h let me think

because u need two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei to form isotopes.

so since they all have the same shape? i mean maybe because m& m and reeses are both chocolates