A buffer is a solution that can resist pH change upon the addition of an acidic or basic components. It is able to neutralize small amounts of added acid or base, thus maintaining the pH of the solution relatively stable. This is important for processes and/or reactions which require specific and stable pH ranges. Buffer solutions have a working pH range and capacity which dictate how much acid/base can be neutralized before pH changes, and the amount by which it will change.
For the given reaction, according to the Law of Conservation of Energy, the energy required to decompose Hcl and produce 
are equal.
Answer: Option C
<u>Explanation:</u>
According to law of conservation's of energy, energy can only be transferred from reactants to product side. So in this process, it is stated that 185 kJ of energy will be needed to decompose it. So that 185 kJ of energy will be getting transferred to produce the creation of hydrogen and chloride in the product side.
So if we see from the reactants side, the energy of 185 kJ is required for decomposition of hydrogen chloride. Similarly, if we see from the product side, the 185 kJ utilized for decomposition is transferred as energy required to create hydrogen and chlorine atoms. This statement will be in accordance with the law of conservation's of energy.
Explanation:
As the charge of all electrons are equal, the repulsive force exerted by each of them is also going to be equal. So, as K has more electrons repulsing its valence electron than Na, it has greater electron shielding.
Answer:
Chemical change.
Explanation:
When it is heated it decomposes into mercury and oxygen gas. The mercury oxide reactant becomes the silver color of mercury. Hence, a color change can be noticed throughout the reaction.
Answer:
The concentration would be; 0.0038 μgmL
Explanation:
Half life, t1/2 = 68 minutes
Initial Conc. [A]o = 0.12/μgmL
Final Conc [A] = ?
Time. k = 340 minutes
ln[A] = ln[A]o - kt
t1/2 = ln2 / k
k = 0.693 / t1/2 = 0.693 / 68 = 0.01019
ln[A] = ln (0.12) - 0.01019 (340)
ln[A] = -2.1203 -3.4646
ln[A] = -5.5849
[A] = 0.00375 ≈ 0.0038 μgmL
