How many electrons are in the outermost shell of the K+ ion in its ground state?

A 5.000 g mixture contains strontium nitrate and potassium bromide. Excess lead(II) nitrate solution is added to precipitate out

scZoUnD [109]

<u>Answer:</u> The mass percent of potassium bromide in the mixture is 9.996%

<u>Explanation:</u>

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$ .....(1)

<u>For lead (II) bromide:</u>

Given mass of lead (II) bromide = 0.7822 g

Molar mass of lead (II) bromide = 367 g/mol

Putting values in equation 1, we get:

$\text{Moles of lead (II) bromide}=\frac{0.7822g}{367g/mol}=0.0021mol$

The chemical equation for the reaction of lead (II) nitrate and potassium bromide follows:

$2KBr+Pb(NO_3)_2\rightarrow PbBr_2+2KNO_3$

By Stoichiometry of the reaction:

1 mole of lead (II) bromide is produced from 2 moles of potassium bromide

So, 0.0021 moles of lead (II) bromide will be produced from = $\frac{2}{1}\times 0.0021=0.0042mol$ of potassium bromide

Now, calculating the mass of potassium bromide by using equation 1, we get:

Molar mass of KBr = 119 g/mol

Moles of KBr = 0.0042 moles

Putting values in equation 1, we get:

$0.0042mol=\frac{\text{Mass of KBr}}{119g/mol}\\\\\text{Mass of KBr}=0.4998g$

To calculate the percentage composition of KBr in the mixture, we use the equation:

$\%\text{ composition of KBr}=\frac{\text{Mass of KBr}}{\text{Mass of mixture}}\times 100$

Mass of mixture = 5.000 g

Mass of KBr = 0.4998 g

Putting values in above equation, we get:

$\%\text{ composition of KBr}=\frac{0.4998g}{5.000g}\times 100=9.996\%$

Hence, the percent by mass of KBr in the mixture is 9.996 %

5 0

2 years ago

1. Determine the amount concentration of calcium ions and acetate ions in a 0.80 mol/L

PIT_PIT [208]

Since there is one mole of Ca^2+ in calcium acetate, its concentration is 0.80 mol/L.

<h3>What is concentration?</h3>

The term concentration has to do with the amount of substance in solution. The concentration can be measured in several units. Generally, concentration is expressed in molarity, molality, mass concentration units or percentage.

Now we are asked to find the amount concentration of calcium ions and acetate ions in a 0.80 mol/L solution of calcium acetate. The formula of calcium acetate is Ca(CH3COO)2.

Thus;

Ca(CH3COO)2(aq) ----> Ca^2+(aq) + 2CH3COO^-(aq)

It then follows that since there is one mole of Ca^2+ in calcium acetate, its concentration is 0.80 mol/L.

Learn more about concentration:brainly.com/question/10725862

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6 0

1 year ago

How many liters of oxygen gas are there in 45.0g O, at 0 degrees C and 1 atm of pressure? make sure to round to the correct numb

ZanzabumX [31]

Answer:

You can use the pdf to help you

Explanation:

Download pdf

3 0

2 years ago

Why is chlorine called non-metal?

finlep [7]

pls follow me

Explanation:

Chlorine is a nonmetal because it does not have the characteristics of a metal. It cannot conduct electricity, it is not flexible, and it is not hard

hope it helps

8 0

2 years ago

Read 2 more answers

How many atoms are there in 4.13 moles of nickel (Ni)

PtichkaEL [24]

Answer:

24.87× 10²³ atoms of Ni

Explanation:

Given data:

Number of atoms of Ni= ?

Number of moles of Ni = 4.13 mol

Solution:

we will calculate the number of atoms of Ni by using Avogadro number.

It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.

The number 6.022 × 10²³ is called Avogadro number.

1 mole = 6.022 × 10²³ atoms

4.13 mol × 6.022 × 10²³ atoms /1 mol

24.87× 10²³ atoms of Ni

6 0

3 years ago

How many electrons are in the outermost shell of the K+ ion in its ground state?​

How many electrons are in the outermost shell of the K+ ion in its ground state?