Answer:
Explanation:
Given parameters;
pH = 8.74
pH = 11.38
pH = 2.81
Unknown:
concentration of hydrogen ion and hydroxyl ion for each solution = ?
Solution
The pH of any solution is a convenient scale for measuring the hydrogen ion concentration of any solution.
It is graduated from 1 to 14
pH = -log[H₃O⁺]
pOH = -log[OH⁻]
pH + pOH = 14
Now let us solve;
pH = 8.74
since pH = -log[H₃O⁺]
8.74 = -log[H₃O⁺]
[H₃O⁺] = 10⁻
[H₃O⁺] = 1.82 x 10⁻⁹mol dm³
pH + pOH = 14
pOH = 14 - 8.74
pOH = 5.26
pOH = -log[OH⁻]
5.26 = -log[OH⁻]
[OH⁻] = 10
[OH⁻] = 5.5 x 10⁻⁶mol dm³
2. pH = 11.38
since pH = -log[H₃O⁺]
11.38 = -log[H₃O⁺]
[H₃O⁺] = 10⁻
[H₃O⁺] = 4.17 x 10⁻¹² mol dm³
pH + pOH = 14
pOH = 14 - 11.38
pOH = 2.62
pOH = -log[OH⁻]
2.62 = -log[OH⁻]
[OH⁻] = 10
[OH⁻] =2.4 x 10⁻³mol dm³
3. pH = 2.81
since pH = -log[H₃O⁺]
2.81 = -log[H₃O⁺]
[H₃O⁺] = 10⁻
[H₃O⁺] = 1.55 x 10⁻³ mol dm³
pH + pOH = 14
pOH = 14 - 2.81
pOH = 11.19
pOH = -log[OH⁻]
11.19 = -log[OH⁻]
[OH⁻] = 10
[OH⁻] =6.46 x 10⁻¹²mol dm³
Explanation:
Given:
Number of atoms = 1.505 x 10²³
Let us solve for the number of moles and mass of this atom of sodium.
A mole of a substance is the amount of that substance that contains the avogadro's number of particles.
1 mole of Na = 6.02 x 10²³ atoms
Number of moles of Na = 
= 0.25moles
Mass of Na = number of moles x molar mass
Molar mass of Na = 23g/mole
Mass of Na = 0.25 x 23 = 5.75g
learn more:
Number of moles brainly.com/question/1841136
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Answer:
a) octahedral electron domain geometry
b)square planar molecular geometry
c) a bond angle of 90°
Explanation:
According to the Valence Shell Electron Pair repulsion Theory, the shape of a molecule is dependent on the number of electron pairs on the valence shell of the central atom in the molecule. These electron pairs orient themselves as far apart in space as possible to minimize electron pair repulsion.
Electron pairs may be lone pairs or bond pairs. Lone pairs of electrons cause more repulsion than bond pairs. These lone pairs often cause the molecular geometry to depart from what is predicted on the basis of the electron domain geometry due to greater repulsion of lone pairs.
When a molecule has six electron domains consisting of four bond pairs and two lone pairs, the bonding pairs arrange themselves at the corners of a square at a bond angle of 90° with the lone pairs found above and below the plane of the bonding groups leading to a square planar molecular geometry
Answer:
option C = all elements are balanced
Explanation:
In given chemical equation all elements are balanced.
Chemical equation:
MgO + 2LiCl → MgCl₂ + Li₂O
This is balanced chemical equation. We can see that there are one Mg atom and one oxygen atom is present in reactant side and also in product side. So, both are balanced.
In case of lithium there are two Li atoms in reactant side and also in product side , it is also balanced.
There are two chlorine atoms are present in reactant side and also in product side. Chlorine atoms are balanced.
Answer:
When an acid and a base are placed together, they react to neautralise the acid and base properties, thus making a salt.
Explanation:
The compound formed by the caption of the base and the anion of the acid is called a salt.
