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

more info ? ? i don't understand what the question is

explanation:

- calcium has greater affinity to bond with electron receptors than hydrogen does and hence, it has the ability to replace hydrogen in most of its compounds.

- lithium has 2 valence electrons in the product because it can make only 1 bond with hydrogen. beryllium has 4 valence electrons in the product because it can only make 2 bonds. it has fewer electrons than neon and can react with electron donors. each hydrogen has 2 valence electrons, the same as helium.

- the covalent bond formed between carbon and hydrogen is polar because carbon is more electronegative than hydrogen and it attracts the bonded electron pair closer to itself, thus giving hydrogen a partial positive charge.

- a hydrogen bond is a relatively weak bond that hydrogen atoms make with the electronegative atoms nitrogen, oxygen or fluorine.

so the best choice is a.) 2 calcium (ca) atoms