Problem Page Question A major component of gasoline is octane C8H18. When liquid octane is burned in air it reacts with oxygen O2 gas to produce carbon dioxide gas and water vapor. Calculate the moles of octane needed to produce 2.4mol of water. Be sure your answer has a unit symbol, if necessary, and round it to the correct number of significant digits. 2.4 Clears your work. Undoes your last action. Provides information about entering answers.

0.3mol C8H18

Explanation:

For this we must first look at the reaction taking place:

C8H18+O2 --> H2O + CO2

Balancing the equation we get:

2(C8H18)+25(O2) --> 18(H2O) + 16(CO2)

Form there we now need to know how many moles of Octane are needed to produce 2.4moles of H2O. The conversion is as follows:

2.4molH2O ((2mol of C8H18)/(18mol of H2O)) = 0.3mol C8H18

the best answer is d because the strong cohesion is caused by the ability of water molecules to undergo hydrogen bonding.

a is incorrect because when water solidifies, it becomes   ice, which expands and occupies a bigger volume for the same mass of water in its liquid state.

b is incorrect because water has high surface tension. besides bonding to itself it hydrogen bonds to other molecules at the top decreasing possibility for breaking of attractive forces.

c is incorrect because the water molecule has oxygen which is highly electronegative and so pulls the electron pair towards itself creating a dipole moment, making the molecule polar.

e is incorrect because water has strong adhesion, ability to stick to other molecules such as glass because of this molecules having stronger hydrogen bonding than water.