Answer:
The mass number is defined as the total number of protons and neutrons in an atom. The number of neutrons = mass number − atomic number.
Answer:
True
Explanation:
It's true because the pH is a measure of how basic or acid a solution is. In an acidic medium, the pH scales goes from 0 to 7. While in a basic medium goes from 7 to 14. The lower the pH value of the most acid the solution is.
1. The expression pH = -log(molar concentration of hydronium) allow to calculate the pH of a solution.
2. On the other hand, the expression pOH = -log(molar concentration of hydroxide) allow to determine the pOH of a solution.
The values of pH and pOH always obey the following expression:
pH + pOH = 14
Thus if for instance the pH becomes smaller the pOH must become bigger in order to fulfill the equation. Which means that the concentration of hydronium ions is greater than the hydroxide concentration.
For example, in an acidic medium:
if pH= 3, pOH= 11
In this case the molar concentration of hydronium is 0,001M. And the molar concentration of hydroxide ions is just 0,00000000001M.
Explanation :
According to the Bronsted Lowry concept, Bronsted Lowry-acid is a substance that donates one or more hydrogen ion in a reaction and Bronsted Lowry-base is a substance that accepts one or more hydrogen ion in a reaction.
Or we can say that, conjugate acid is proton donor and conjugate base is proton acceptor
The given equilibrium reaction is,

In this reaction,
and
are act as Bronsted Lowry base and acid respectively and
and
are act as Bronsted Lowry acid and base respectively.
The formula of conjugate of
is, 
The formula of conjugate of
is, 
The pressure of hydrogen gas formed is 720.8 mmHg.
<h3>What is Partial Pressure ?</h3>
The pressure exerted by a (specified) component in a mixture of gases.
We have to understand one thing that the Hydrogen, which is collected over water, will be mixed with water vapor.
This means that the total pressure of the mixture will have two components.
- the partial pressure of Hydrogen
- the vapor pressure of water at 21.5 C
The vapor pressure of water at that temperature is approximately
19.231 mmHg.
This means that

740 =
+ 19.231
= 740-19.231
= 720.8 mmHg
Therefore the pressure of hydrogen gas formed is 720.8 mmHg.
To know more about Partial Pressure
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Answer:
3.50 kg
Explanation:
Law of definite proportion: These law states that all pure samples of a particular chemical compound contains similar elements combined in the same proportion by mass.
From the law above,
First sample,
The ratio of fluorine and magnesium in the sample of magnesium fluoride is
0.764:1.19 = 1:1.6
mass of fluorine: mass of magnesium ≈ 1:1.6
Second sample,
mass of magnesium fluoride = 5.75 kg
mass of magnesium = 1.19(5.75)/(1.19+0.764)
mass of magnesium = 6.8425/1.954
mass of magnesium = 3.50 kg
Hence the second sample produced 3.50 kg of magnesium.