Answer:
2.645
Explanation:
Rate of diffusion formula:
Sqrt(mass2/mass1)
>>sqrt(14/2)
(Note:Hydrogen must exist in dwiatomic, [H2])
Answer:
a) [H₃O⁺] = 1.8x10⁻⁵ M
b) pH = 4.75
c) % rxn = 3.5x10⁻³ %
Explanation:
a) The dissociation reaction of HCN is:
HCN(aq) + H₂O(l) ⇄ H₃O⁺(aq) + CN⁻(aq)
0.5 M - x x x
The dissociation constant from the above reactions is given by:
![Ka = \frac{[H_{3}O^{+}][CN^{-}]}{[HCN]} = 6.17 \cdot 10^{-10}](https://tex.z-dn.net/?f=Ka%20%3D%20%5Cfrac%7B%5BH_%7B3%7DO%5E%7B%2B%7D%5D%5BCN%5E%7B-%7D%5D%7D%7B%5BHCN%5D%7D%20%3D%206.17%20%5Ccdot%2010%5E%7B-10%7D)
By solving the above quadratic equation we have:
x = 1.75x10⁻⁵ M = 1.8x10⁻⁵ M = [H₃O⁺] = [CN⁻]
Hence, the [H₃O⁺] is 1.8x10⁻⁵ M.
b) The pH is equal to:
![pH = -log[H_{3}O^{+}] = -log(1.75 \cdot 10^{-5} M) = 4.75](https://tex.z-dn.net/?f=pH%20%3D%20-log%5BH_%7B3%7DO%5E%7B%2B%7D%5D%20%3D%20-log%281.75%20%5Ccdot%2010%5E%7B-5%7D%20M%29%20%3D%204.75)
Then, the pH of the HCN solution is 4.75.
c) The % reaction is the % ionization:
![\% = \frac{x}{[HCN]} \times 100](https://tex.z-dn.net/?f=%20%5C%25%20%3D%20%5Cfrac%7Bx%7D%7B%5BHCN%5D%7D%20%5Ctimes%20100%20)
Therefore, the % reaction or % ionization is 3.5x10⁻³ %.
I hope it helps you!
Answer:
c tarnishes in air
Explanation:
After silver has been exposed to air that contains sulphur gases, discoloration would occur. there would be darkening that is caused by the reaction with gases.When any silver object tarnishes, it brings about a disfiguring of that object. Hydrogen sulphide would be needed for this to happen. silver sulphide is black and a if a thin layer should form on any surface, it ill darken it. This is what we refer to as tarnishing.
Elements that are usually shiny and good conductors of heat and electricity are metals.
<h3>What are conductors?</h3>
The conductors are the metal or non metal elements which allow heat and electricity to easily pass through them.
Metals are elements with good conductivity of electric current and heat. Metals have lustre characteristics. They are shiny and bendable just like copper wire, which is a metal.
Hence, elements that are usually shiny and good conductors of heat and electricity are metals.
Learn more about conductors.
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