Answer:
The molar mass (Mm) of the compound is 127.39 g/mole
Explanation:
ΔT = Kf. molality
ΔT = change in temperature = Tfinal - Tinitial = 2.8 - 5.5
Kf = freezing point depression constant = - 4.3 C/m (always negative because temperature is decreasing)
molality = moles of solute/Kg of solvent = mole (n)/(20 x 10^-3 Kg of benzene)
(2.8 - 5.5) = (-4.3) x molality
molality = 0.6279 mole/kg
0.6279 = mole of compound/(20 x 10^-3)
mole of compound = 0.01256 mole
mole (n) = mass (m) divided by Molar mass (Mm)
Molar mass = mass of compound / mole of compound
m/n = 1.6/0.01256 = 127.39 g/mole
Answer:
The answer is 12.35
Explanation:
From the question we are given that the concentration of
is
Generally The rate equation is given as
![K_{w} = [H^{+} ][OH^{-} ]](https://tex.z-dn.net/?f=K_%7Bw%7D%20%3D%20%5BH%5E%7B%2B%7D%20%5D%5BOH%5E%7B-%7D%20%5D)
and
the rate constant has a value 
Substituting and making [
] the subject we have
![[OH^{-} ] = \frac{1 * 10^{-14}}{[H^{+}]} = \frac{1 * 10^{-14}}{8.1 *10^{-6}} =1.235 * 10^{-9}](https://tex.z-dn.net/?f=%5BOH%5E%7B-%7D%20%5D%20%3D%20%5Cfrac%7B1%20%2A%2010%5E%7B-14%7D%7D%7B%5BH%5E%7B%2B%7D%5D%7D%20%3D%20%5Cfrac%7B1%20%2A%2010%5E%7B-14%7D%7D%7B8.1%20%2A10%5E%7B-6%7D%7D%20%3D1.235%20%2A%2010%5E%7B-9%7D)
![[OH ^ {-}] = 1.235 * 10^{-9}M](https://tex.z-dn.net/?f=%5BOH%20%5E%20%7B-%7D%5D%20%3D%201.235%20%2A%2010%5E%7B-9%7DM)
Multiply the value by
as instructed from the question we have
Answer =
Hence the answer in 2 decimal places is 12.35
Charles Darwin was a Geologist, biologist and is best known for his contributions to science of evolution.
Answer:
D. Gases were released to the atmosphere
Explanation:
In accordance to the law of conservation of mass, the total amount of reactants must equate the total amount of products at the end of the reaction because matter can not be lost or created. However, certain changes like gas evolution, formation of precipitate etc. indicates the occurrence of a chemical reaction.
In a chemical reaction, the total mass of the product(s) would be less than the total weight of the reactant(s) because GASES, which constituted part of the mass of the reaction, WERE RELEASED INTO THE ATMOSPHERE. However, if the mass of the gas released can be accounted for, the amount of reactants and products must balance.
Answer:
<em>C. Potential energy</em>
Explanation:
Kinetic energy and gravitational potential energy are both forms of potential energy. Potential energy is stored energy, when an object is not in motion it has stored energy. When an object is an motion it has kinetic energy. An object posses gravitational potential energy when it is above or below the zero height.