Answer:
This law states that, despite chemical reactions or physical transformations, mass is conserved — that is, it cannot be created or destroyed — within an isolated system. In other words, in a chemical reaction, the mass of the products will always be equal to the mass of the reactants.
Explanation:
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: Option (c) is the correct answer.
Explanation:
A hydrogen bond is defined as a weak bond that is formed between an electropositive atom (generally hydrogen atom) and an electronegative atom like oxygen, nitrogen and fluorine.
An ionic bond is defined as a bond formed between a metal and a non-metal and in this bond transfer of electron takes place from metal to non-metal. And, due to the presence of opposite charges on the combining atoms there exists a strong force of attraction.
Vander waal forces are defined as the weak electric forces which tend to attract neutral molecules towards each other in gases, liquefied and solidified gases.
Vander waal forces are very weak forces.
Thus, we can conclude that Van der walas interactions are weak interactions would require the least amount of energy to disrupt.
Answer:
The answer to your question is 92.7%
Explanation:
Balanced Chemical reaction
3 Zn + Fe₂(SO₄)₃ ⇒ 2Fe + 3ZnSO₄
Molecular weight
Zinc = 65.4 x 3 = 196.2g
Iron (III) = 56 x 2 = 112 g
Proportions
196.2 g of Zinc ------------------ 112 g of Iron
20.4 g of Zinc ----------------- x
x = (20.4 x 112) / 196.2
x = 2284.8/196.2
x = 11.65 g of Iron
% yield = 
% yield = 0.927 x 100
% yield = 92.7
Explanation:
According to Bohr's postulates, the electron in the present in the lower energy level can absorb energy and exits to higher energy level. Also, when this electron returns back to its orbit, it emits some energy.
Since the hydrogen consists of 1 electron and 1 proton. The lowest energy configuration of the hydrogen is when n =1 or, when the electron is present in the K-shell or the ground state.
The possible transition for the electron given in the question is :
n = 2, 3 and 4
The schematic diagram of the hydrogen atom consisting of these four quantum levels in which the electron can jump (Absorption) and comeback to from these energy levels (emission) .