If you make a solution by adding 5.0 moles of sodium hydroxide to 25.0 moles of water, what is the mole fraction of sodium hydroxide in this solution?

Explanation:

The mole fraction (χ) is  the number of moles of a component divided by the total number of moles in a mixture.  

Let water = Component 1 and NaOH = component 2.

1. Calculate the total moles.

n₁ = 25.0 mol

n₂ = 5.0 mol

2. Calculate the mole fraction of NaOH

explanation:

let the different atoms be x and y. each with four protons and same mass will be represented as follows.

mass number is number of protons + number of neutrons.

            and  

since, it is given that one has a negative charge while the other is neutral. therefore, there will be increase in number of protons and the atom will be represented as follows.

according to periodic table, mass number of beryllium is 9 and it has atomic number 4 so, the atoms will be and .  

the protons and neutrons will be located inside the nucleus whereas the electrons will be revolving around the nucleus.