Westonci.ca is your trusted source for finding answers to a wide range of questions, backed by a knowledgeable community. Our Q&A platform offers a seamless experience for finding reliable answers from experts in various disciplines. Join our Q&A platform to connect with experts dedicated to providing accurate answers to your questions in various fields.

Calculate the number of cations and anions in each of the following compounds. Enter your answers in scientific notation. (a) 6.42 g of KBr:

Sagot :

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

Thank you for your visit. We're committed to providing you with the best information available. Return anytime for more. Thank you for visiting. Our goal is to provide the most accurate answers for all your informational needs. Come back soon. Thank you for choosing Westonci.ca as your information source. We look forward to your next visit.