C sounds like the right answer in this question
Answer:
Pure Substances are made of the same material throughout and have the same properties throughout. Pure substances cannot be separated into other substances. Some examples are carbon, iron, water, sugar, salt, nitrogen gas, and oxygen gas. ... If so, you have a pure substance.
Hope this helps!!
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Answer: 0.422 M⁻¹s⁻¹
Explanation: <u>Reaction</u> <u>Rate</u> is the speed of decomposition of the reactant(s) per unit of time.
A <u>Rate</u> <u>Law</u> relates concentration of reactants, rate reaction and rate constant:
![r=k[A]^{x}[B]^{y}](https://tex.z-dn.net/?f=r%3Dk%5BA%5D%5E%7Bx%7D%5BB%5D%5E%7By%7D)
where
[A] and [B] are reactants concentration
x and y are reaction order, not related to the stoichiometric coefficients
k is rate constant
r is rate
Before calculating rate constant, first we have to determine reaction order.
In this question, the reactio order is 2. So, the rate law for it is
![-\frac{d[A]}{dt} =k[A]^{2}](https://tex.z-dn.net/?f=-%5Cfrac%7Bd%5BA%5D%7D%7Bdt%7D%20%3Dk%5BA%5D%5E%7B2%7D)
and the integrated formula is
![\frac{1}{[A]} =\frac{1}{[A]_{0}} +kt](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B%5BA%5D%7D%20%3D%5Cfrac%7B1%7D%7B%5BA%5D_%7B0%7D%7D%20%2Bkt)
in which
[A]₀ is initial concentration of reactant
Then, using initial concentration at initial time and final concentration at final time:



k = 0.422
The rate constant for the reaction is 0.422 M⁻¹.s⁻¹
Answer:
Molecules start out unevenly distributed and end up evenly distributed.
Explanation:
Diffusion is the process by which molecules of a substance move from a region of higher concentration to a region of lower concentration until equilibrium is attained.
Molecules start out unevenly distributed and end up evenly distributed in a particular medium. Diffusion occurs due to the particulate nature of matter. When the particles that make up a substance are concentrated at a point, the collide more often with one another causing each molecule to spread out in order to occupy all the available space.
Diffusion occurs in gases, liquids and solids but occurs fastest in gases. Diffusion can be observed for example, in the spread of the smell of a dead rat from one point in a room to every part of the room.