The balanced equation for the above reaction is as follows;
2C₈H₁₈ + 25O₂ ---> 16CO₂ + 18H₂O
stoichiometry of octane to CO₂ is 2:16
number of C₈H₁₈ moles reacted - 191.6 g / 114 g/mol = 1.68 mol
when 2 mol of octane reacts it forms 16 mol of CO₂
therefore when 1.68 mol of octane reacts - it forms 16/2 x 1.68 = 13.45 mol of CO₂
number of CO₂ moles formed - 13.45 mol
therefore mass of CO₂ formed - 13.45 mol x 44 g/mol = 591.8 g
mass of CO₂ formed is 591.8 g
The density of gasoline is 0.7 g/cm3, and the density of water is 1 g/cm3. Thus the mass of the gasoline is 55*0.7 = 38.5g and the mass of the water is 60g.
Combining the 55 cm3 and 60 cm3 of substances with the aforementioned masses yields a volume of 55+60 = 115cm3 and a mass of 38.5+60 = 98.5g. The density is therefore 98.5/115 = 0.86 g/m3.
Parabolic and they use it because light hits your face (the focal point) and gets reflected in the mirror. The concave, or parabolic, shape of the mirror surface concentrates the light beams, intensifying light as it gets closer to the focal point! :)
Answer:
1. The length of the wire is halved.
the resistance of a conductor is directly proportional to it's length (L) as R - L. Thus doubling it's length will double it's resistance, while halving it's length would halve the resistance. Also the resistance of a conductor is inversely proportional to it's cross sectional area.
2. The area of cross-section of the conductor in increased.
On increasing the area of cross-section, resistance decreases. Thus is because resistance is inversely proportional to area.
3. The temperature of the conductor is increased.
With increasing temperature, the resistance of the wire increases as collisions within the wire increases and "slow" the flow of current... Since conductors typically display an increased resistivity with temperature increase, they have a positive temperature coefficient.
If the pH is 7, the solution is neutral, which means that it is an equal amount of acid and base.
