Respuesta :
Answer: The number of cations are [tex]3.24 \times 10^{22}[/tex] and number of anions are [tex]3.24 \times 10^{22}[/tex] in 6.42 g of KBr.
Explanation:
The molar mass of KBr is (39.10 + 79.90) g/mol = 119.00 g/mol
Now, the dissociation equation for KBr is as follows.
[tex]KBr \rightarrow K^{+} + Br^{-}[/tex]
This means that 1 mole of KBr is forming 1 mole of [tex]K^{+}[/tex] (cation) and 1 mole of [tex]Br^{-}[/tex] (anion).
According to mole concept, 1 mole of every substance contains [tex]6.022 \times 10^{23}[/tex] atoms. Hence, number of cations present in 6.42 g KBr is calculated as follows.
[tex]No. of cations = Moles \times 6.022 \times 10^{23}\\= \frac{mass}{molar mass} \times 6.022 \times 10^{23}\\= \frac{6.42 g}{119.00 g/mol} \times 6.022 \times 10^{23}\\= 3.24 \times 10^{22}[/tex]
As according to the equation, there are equal number of moles of both cation and anions.
This means that the number of anions are also [tex]3.24 \times 10^{22}[/tex].
Thus, we can conclude that the number of cations are [tex]3.24 \times 10^{22}[/tex] and number of anions are [tex]3.24 \times 10^{22}[/tex] in 6.42 g of KBr.
The number of cations and anions present in potassium bromide is 3.24 × 10²².
How we calculate atoms from moles?
In one mole of any substance 6.022 × 10²³ atoms of that substance is present and this is known as Avogadro's number.
KBr is a strong electrolyte means it fully dissociates into their constitute ions. So, the number of moles of produced ions is equal to the moles of KBr and dissociation is represented as:
KBr → K⁺ + Br⁻
From this it is clear that 1 mole of cation and 1 mole of anion is produced from 1 mole of KBr. Moles of KBr will be calculated as:
n = W/M, where
W = given mass = 6.42g
M = molar mass = 119
n = 6.42 / 119 = 0.053 moles
No. of cations and anions present in 0.053 moles = 0.053 × 6.022 × 10²³ = 3.24 × 10²².
Hence, 3.24 × 10²² is the no. of cations and anions.
To know more about Avogadro's number, visit the below link:
https://brainly.com/question/10614569
