Answer : The pH of the solution is, 9.63
Explanation : Given,
The dissociation constant for HCN = 
First we have to calculate the moles of HCN and NaCN.

and,

The balanced chemical reaction is:

Initial moles 0.1116 0.0461 0.08978
At eqm. (0.1116-0.0461) 0 (0.08978+0.0461)
0.0655 0.1359
Now we have to calculate the pH of the solution.
Using Henderson Hesselbach equation :
![pH=pK_a+\log \frac{[Salt]}{[Acid]}](https://tex.z-dn.net/?f=pH%3DpK_a%2B%5Clog%20%5Cfrac%7B%5BSalt%5D%7D%7B%5BAcid%5D%7D)
Now put all the given values in this expression, we get:


Therefore, the pH of the solution is, 9.63
Answer:
b. the layer of oxide formed on statues made of metal
Explanation:
Chemical weathering is a process whereby rocks are disintegrated or weathered causing a chemical reaction thereby leading to change in the parent rock constituents .
In chemical weathering a new substance is usually formed after the weathering takes place.
From the question the layer of statue made by metal will likely form oxides of those metals. Example Silver will react with oxygen to form an entirely new substance like silver(i)oxide.
Answer:
3m/s
Explanation:
Data obtained from the question include:
Initial speed (s1) = 4 m/s
Final speed (S2) = 7m/s
Change in speed (ΔS)
ΔS = s2 — s1
ΔS = 7 — 4
ΔS = 3m/s
Therefore, the change in speed is 3m/s
The basic building blocks of proteins are the amino acids. There are 20 amino acids in a protein that we consume and the protein in our body. These amino acids link together to form large molecules. The 20 amino acids are divided into two groups called the essential and non-essential amino acids.
If the crucible wasn't covered with a lid the reactants may have produced a gas that was released into the surroundings, or mass may have been lost in the form of water vapour.