The automobile fuel called e85 consists of 85% ethanol and 15% gasoline. e85 can be used in so-called flex-fuel vehicles (ffvs), which can use gasoline, ethanol, or a mix as fuels. assume that gasoline consists of a mixture of octanes (different isomers of c₈h₁₈), that the average heat of combustion of c₈h₁₈(l) is 5400 kj/mol, and that gasoline has an average density of 0.70 g/ml. the density of ethanol is 0.79 g/ml. by using the information given, calculate the energy produced by combustion of 1.5 l of gasoline. express your answer to two significant figures and include the appropriate units.

49,736.84 kJ

Explanation:

1 L of gasoline has 0.70 kg

1,5 L of gasoline has x kg

1 L - 0.70 kg

1.5 - x

x = 0.7 *1.5 = 1,05 kg

1 mol of gasoline has 114 g

y mol of gasoline has 1050 g

1 mol - 114 g

y - 1050 g

y = = 9.21 mol

1 mol of gasoline has a combustion heat of 5400 kJ

9.21 mol of gasoline has a combustion heat of z

z = 5400 * 9.21 = 49,736.84 kJ

answer:

the answer is 6 valence electrons.

explanation:

valence is the # of electrons on the outer most shell of an atom.

oxygen has 6.

although, the valency of oxygen is 2, because it only needs to make 2 covalent bonds, or gain 2 electrons, to achieve the stable octet configuration of a noble gas.

that's it!

if you need further assistance, let me know: )

~ trueboss72