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:
1.67 M
Explanation:
The following data were obtained from the question:
Initial volume (V1) of solution = 250 mL
Initial Molarity (M1) of solution = 0.5 M
Final volume (V2) of solution = 75 mL
Final Molarity (M2) of solution =?
Thus, we can obtain the final molarity of the solution by using the following formula:
M1V1 = M2V2
0.5 × 250 = M2 × 75
125 = M2 × 75
Divide both side by 75
M2 = 125 /75
M2 = 1.67 M
Thus, the new Molarity of the solution is 1.67 M.
Explanation:
Magnesium is more reactive then chromium. So, when magnesium hydroxide reacts with chromium (lll) iodide then magnesium displaces chromium.
When magnesium hydroxide and chromium (lll) iodide are mixed together then it results in the formation of magnesium iodide and chromium hydroxide.
The chemical reaction equation is as follows.
Balanced Equation: 2Mg + O2 ➡️ 2MgO
125 x 2= 250 102 x 2= 204
250 + 204= 454
So the answer should be 454 grams of magnesium oxide should be produced.
Answer: (A) It appears as a reactant in the net chemical reaction
Explanation:
A catalyst is A substance that speed up the chemical reaction without its self being consumed in the reactants or the products.It does this by lowering the activation energy of the reaction by speeding up the rate of reaction.
