Answer: 0.0009 moles of octane were used up.
Explanation:
To calculate the moles :
Given mass of octane = 0.1 g
Molar mass of octane = 11.23 g/mol
Putting in the values we get:

Thus 0.0009 moles of octane were used up.
Answer:
0.023
Explanation:
The Arrhenius' equation states that:

Where k is the velocity constant of the reaction, A is the constant of the collisions, Ea is the activation energy (the energy necessary to the molecules have so the reaction will happen), R is the gas constant (8.314 J/molK) and T is the temperature.
This equation is derivated of:
k = pZf
Where
p=fraction of collisions that occur with reactant molecules properly oriented
f=fraction of collisions having energy greater than the activation energy
Z=frequency of collisions
Thus, p*Z = A, and
f = 
So, if the energy of the molecules is 12.5 kJ/mol = 12500 J/mol, thus the fraction will be:
f = 
f = 0.023
Answer: C
Explanation:
Velocity is displacement over change in time. It’s a vector quantity, so velocity must include direction. You’re changing the direction, but the speed stays the same, because you are still going 20 km per hr
7. D. 668 joules
8. B. 3 grams
<h3>Further explanation</h3>
Given
2 grams of water
6768 joules of energy
Required
Energy
Mass of water
Solution
The heat to change the phase can be formulated :
Q = m.Lf (melting/freezing)
Q = m.Lv (vaporization/condensation)
Lf=latent heat of fusion
Lv=latent heat of vaporization
7. phase change (ice to water)⇒Heat of fusion water=334 J/g
Q = 2 g x 334 J/g
Q = 668 J
8. phase change(water to vapor)⇒heat of vaporization water=2260 J/g
6768 J = m x 2260 J/g
m = 3 g
Answer:
14
Explanation:
The sum of pH and pOH is always equal to 14.