Answer:
It does. They trap particles so they don’t enter.
Explanation:
If all the reactants will react and become products, the mass will be 12.5 g. Because the mass of the matter amount will not change during the reaction.
Answer:

Explanation:
We have the reactions:
A: 
B: 
Our <u>target reaction</u> is:

We have
as a reactive in the target reaction and
is present in A reaction but in the products side. So we have to<u> flip reaction A</u>.
A: 
Then if we add reactions A and B we can obtain the target reaction, so:
A: 
B: 
For the <u>final Kc value</u>, we have to keep in mind that when we have to <u>add chemical reactions</u> the total Kc value would be the <u>multiplication</u> of the Kc values in the previous reactions.


Answer:
According to the proton theory of acids and bases by J. Brønsted and T. Lowry, the acid is<u> proton donor</u>.
Explanation:
According to the Bronsted lowry concept an acid is substance that gives protons or hydrogen ion while,
Base is substance that accept hydrogen ion or proton.
Consider the following example:
NH₃ + HCl → NH₄⁺ + Cl⁻
In this example HCl is Bronsted lowry acid it gives H⁺ while ammonia is Bronsted lowry base because it accept H⁺.
This also gives the concept of conjugate acid and base. In given example Cl⁻ is conjugate base of HCl while NH₄⁺ is conjugate acid of ammonia.