Single Replacement Reactions and Net Ionic Equations

Summary

This educational video script delves into single replacement reactions, illustrating how metals react with solutions to form new elements and compounds. Key concepts like the activity series, oxidation states, and the crisscross method for writing chemical formulas are explained. The script guides viewers through balancing chemical equations and identifying redox processes, using examples like aluminum in copper chloride solution and zinc with hydrochloric acid. It also clarifies when reactions are feasible based on the reactivity of metals and nonmetals, and discusses the role of spectator ions in net ionic equations.

Takeaways

• 🔬 **Single Replacement Reactions**: The video explains single replacement reactions, where one element replaces another in a compound.
• 🌟 **Activity Series**: It introduces the concept of the activity series, which is crucial for determining if a reaction will occur based on the reactivity of metals.
• ⚔️ **Reactivity and Displacement**: Aluminum can displace copper from copper chloride due to its higher position in the activity series, indicating it is more reactive.
• 🧪 **Writing Equations**: The video demonstrates how to write balanced chemical equations and net ionic equations for single replacement reactions.
• 🔄 **Oxidation and Reduction**: It explains that single replacement reactions are redox reactions, involving the transfer of electrons where one substance is oxidized and the other is reduced.
• 📚 **Understanding Solubility**: The solubility rules are discussed to determine the state (solid, liquid, gas, or aqueous) of the products in a reaction.
• 📉 **Determining Products**: The video shows how to predict the products of a reaction and whether it will proceed based on the positions of elements in the activity series.
• 🔋 **Reducing and Oxidizing Agents**: It clarifies the roles of reducing and oxidizing agents in chemical reactions, with examples from the reactions discussed.
• 🌐 **Phases of Reactants**: The importance of noting the phases of reactants and products (solid, liquid, gas, aqueous) in writing chemical equations is highlighted.
• 🚫 **Non-Reactive Scenarios**: The video also covers scenarios where reactions will not occur, such as when iron is placed in a zinc chloride solution, due to iron being less reactive than zinc.

Q & A

What is a single replacement reaction?

A single replacement reaction is a type of chemical reaction where one element in a compound is replaced by another element.

What happens when aluminum metal is placed in a copper chloride solution?

In a copper chloride solution, aluminum metal replaces copper metal, forming aluminum chloride and solid copper.

How do you write the net ionic equation for the reaction between aluminum and copper chloride?

The net ionic equation is written by eliminating the spectator ions, which are the ions that appear unchanged on both sides of the reaction. For aluminum and copper chloride, the net ionic equation is 2 Al(s) + 3 Cu^2+(aq) → 2 Al^3+(aq) + 3 Cu(s).

How can you determine if a single replacement reaction will work?

You can determine if a single replacement reaction will work by referring to the activity series. If the metal in the pure element form is higher on the activity series than the metal in the compound, it will displace the metal in the compound.

What are the products of the reaction between zinc metal and hydrochloric acid?

The products of the reaction between zinc metal and hydrochloric acid are zinc chloride and hydrogen gas.

Why is it important to balance the chemical equation in a single replacement reaction?

Balancing the chemical equation ensures that the number of atoms of each element is the same on both sides of the equation, following the law of conservation of mass.

What is the role of aluminum in the single replacement reaction with copper chloride?

In the single replacement reaction with copper chloride, aluminum acts as the reducing agent, as it loses electrons and gets oxidized.

What is the significance of the activity series in predicting the outcome of a single replacement reaction?

The activity series is significant because it predicts which metal will displace another in a reaction based on their reactivity. Metals higher on the series will displace those lower on the series.

How do you determine the phases of the substances in a chemical reaction?

The phases of substances in a chemical reaction are determined by their physical states at standard temperature and pressure. For example, metals are often in the solid phase, gases are in the gaseous phase, and compounds that dissolve in water are in the aqueous phase.

What is the difference between a total ionic equation and a net ionic equation?

The total ionic equation includes all the ions present in the reaction, while the net ionic equation only includes the ions that actually participate in the reaction, excluding the spectator ions that are the same on both sides of the reaction.

Outlines

00:00

🔬 Single Replacement Reactions: Aluminum and Copper Chloride

This paragraph introduces single replacement reactions with a focus on the reaction between aluminum metal and a copper chloride solution. It explains how aluminum, being more reactive, replaces copper in the solution. The process involves aluminum combining with chlorine to form aluminum chloride (AlCl3), while copper is displaced as a solid. The paragraph guides through balancing the chemical equation and determining the solubility of the products. It also discusses the activity series, emphasizing that aluminum's position above copper in the series confirms the reaction's feasibility. The concept of the net ionic equation is introduced, highlighting the need to separate aqueous substances into ions and identify spectator ions, which are ions that appear unchanged on both sides of the reaction.

05:02

🔋 Zinc and Hydrochloric Acid: A Redox Single Replacement Reaction

The second paragraph delves into another single replacement reaction, this time between zinc metal and hydrochloric acid. It outlines the process of zinc displacing hydrogen, forming zinc chloride and hydrogen gas. The paragraph explains the concept of oxidation states and how they change during the reaction, identifying zinc as the reducing agent and hydrogen ions as the oxidizing agents. The summary includes the step-by-step process of writing the total ionic equation, identifying spectator ions, and deriving the net ionic equation. It also touches on the solubility rules, noting that zinc chloride is soluble, and the importance of the activity series in predicting the reaction's outcome.

10:03

🌐 Halogens Activity Series: Chlorine Displacing Bromine

The third paragraph explores a halogen displacement reaction where chlorine gas is bubbled through a solution of aqueous sodium bromide. It discusses the activity series of halogens and how chlorine's position above bromine indicates that chlorine can displace bromine. The paragraph details the formation of sodium chloride and elemental bromine, and it guides through balancing the chemical equation. It also explains how to write the total ionic equation and identifies sodium as a spectator ion. The net ionic equation is derived by eliminating the spectator ions, and the paragraph concludes with a discussion on the oxidizing and reducing agents, identifying chlorine as the oxidizing agent and bromide as the reducing agent.

15:05

⛓ Iron and Zinc Chloride: An Inactive Displacement Reaction

This paragraph presents a scenario where iron metal is placed in a zinc chloride solution. It uses the activity series to explain why no reaction occurs, as iron is less reactive than zinc and cannot displace it. The paragraph emphasizes the importance of the activity series in determining whether a single replacement reaction will proceed. It serves as a reminder that not all metal-salt combinations will result in a reaction, and understanding the reactivity series is crucial for predicting chemical behavior.

20:08

⚛️ Sodium and Hydrochloric Acid: A Reactive Metal-Acid Interaction

The final paragraph discusses the reaction between sodium metal and hydrochloric acid, highlighting sodium's high reactivity due to its position above hydrogen in the activity series. It describes the formation of sodium chloride and hydrogen gas, and it walks through the process of balancing the chemical equation. The summary includes writing the total ionic equation and notes that hydrofluoric acid (HF), being a weak acid, should not be separated into ions in the ionic equation. The paragraph concludes with the identification of sodium as the reducing agent and HF as the oxidizing agent, summarizing the key concepts of single replacement reactions.

Keywords

💡Single Replacement Reaction

A single replacement reaction, also known as a displacement reaction, involves an element replacing another in a compound. In the context of the video, aluminum metal is used to displace copper from a copper chloride solution, resulting in aluminum chloride and copper metal. This reaction is central to the video's exploration of chemical reactions and their outcomes.

💡Net Ionic Equation

The net ionic equation is a chemical equation that includes only those species that actually participate in the reaction, excluding the spectator ions that remain unchanged. In the video, the net ionic equation is derived from the total ionic equation by removing the spectator ions, such as chloride ions in the reaction between aluminum and copper chloride.

💡Crisscross Method

The crisscross method is a technique used to write the formula of an ionic compound by exchanging the charges of the cations and anions to determine the subscript numbers. The video explains how to use this method to write the formula for aluminum chloride (AlCl3) when aluminum metal reacts with chlorine from copper chloride.

💡Solubility Rules

Solubility rules are guidelines that predict whether a compound will dissolve in water. The video uses these rules to determine the state of copper chloride and aluminum chloride in the reaction mixture, concluding that both are soluble and thus will be present in the aqueous phase.

💡Activity Series

The activity series is a list of metals arranged in order of decreasing reactivity. It is used to predict whether a single replacement reaction will occur. In the video, the activity series is referenced to explain why aluminum can displace copper, and why iron cannot displace zinc from zinc chloride.

💡Oxidation

Oxidation is a chemical process where a substance loses electrons. In the video, aluminum metal is oxidized to aluminum ions, losing electrons in the process, which is a key part of the single replacement reaction with copper chloride.

💡Reduction

Reduction is the gain of electrons by a substance. In the context of the video, copper ions are reduced from a +2 oxidation state to a 0 oxidation state as they gain electrons and are displaced as copper metal.

💡Reducing Agent

A reducing agent is a substance that donates electrons to another substance. In the video, aluminum acts as a reducing agent because it loses electrons and is oxidized during the reaction with copper chloride.

💡Oxidizing Agent

An oxidizing agent is a substance that accepts electrons from another substance. In the video, the copper ions in copper chloride act as an oxidizing agent because they gain electrons and are reduced to copper metal.

💡Spectator Ions

Spectator ions are ions that appear on both sides of a reaction equation and do not participate in the reaction. In the video, chloride ions are identified as spectator ions in the reaction between zinc and hydrochloric acid, as they remain unchanged.

💡Total Ionic Equation

The total ionic equation is a chemical equation that shows all the species in the solution, including the ions, before any reaction takes place. In the video, the total ionic equation is written for reactions involving aluminum, copper chloride, and other substances, before simplifying to the net ionic equation.

Highlights

Introduction to single replacement reactions and their products.

Explanation of how to write the net ionic equation for a single replacement reaction.

Using the crisscross method to write formulas between metals and non-metals.

Determining the solubility of compounds like copper chloride.

Balancing the single replacement reaction by finding the least common multiple of chlorine atoms.

Understanding the activity series and its role in predicting reaction outcomes.

Identifying aluminum as a more reactive metal than copper based on the activity series.

Writing the total ionic equation for a reaction involving aluminum and copper chloride.

Eliminating spectator ions to derive the net ionic equation.

Discussing single replacement reactions as redox reactions involving electron transfer.

Example of a reaction between zinc metal and hydrochloric acid, including product identification.

Determining if zinc can displace hydrogen from the solution using the activity series.

Balancing the reaction between zinc and hydrochloric acid.

Writing the total ionic equation for the reaction between zinc and hydrochloric acid.

Identifying oxidizing and reducing agents in a single replacement reaction.

Example of a reaction between chlorine gas and aqueous sodium bromide, including product prediction.

Using the activity series for halogens to predict the outcome of reactions involving chlorine and bromine.

Writing the net ionic equation for the reaction between chlorine gas and sodium bromide.

Example of a non-reactive scenario between iron metal and zinc chloride due to their positions on the activity series.

Example of a reaction between sodium metal and hydrochloric acid, predicting the products and writing the net ionic equation.

Highlighting the difference between strong and weak acids in ionic equations, using HF as an example.

Conclusion of the video with a summary of key points about single replacement reactions.

Transcripts

in this video we're going to go over

single replacement

reactions so let's start with the first

one let's say if you have aluminum

metal placed in a solution

of copper

chloride what are the products of this

reaction and also how can you write the

net ionic

equation so in a single replacement

reaction aluminum metal is going to

replace copper

metal and in the process aluminum is

going to pair up with

chlorine as in metal aluminum has a plus

three

charge and chlorine has a minus one

charge so to write the formula between

aluminum and chlorine you need to use

the crisscross method so it's going to

be

A1

cl3 now as copper is displaced out of

the solution it's going to come out as

CU aluminum is a metal so it's in a

solid phase and copper is in a solid

phase copper chloride is it soluble or

insoluble what would you say now you

need to know your solubility

rules chlorides are usually soluble

except with silver lead and Mercury so

copper chloride is in the aquous phase

and the same is true for aluminum

chloride so now the next thing we need

to do is balance the single replacement

reaction so feel free to pause the video

and balance

it so notice that we

have two chlorine atoms on the left and

three on the right

what is the least common multiple of two

and three the LCM of two and three is

six so what we need to do is try to get

six chlorine atoms on both

sides therefore we need to put a three

in front of

cucl2 and a two in front of

al3 so now we have six chlorine

atoms but notice that we have three

copper atoms on the left so we need a

three in front of Cu and we have two

aluminum atoms on the right so we need a

two in front of Al so now the reaction

is

balanced now before we write the net

ionic equation how can we determine if

this reaction is going to work in the

first place is aluminum strong enough to

displace copper out of the solution now

there's something called the activity

series and if you don't have it you can

go to Google images and look it

up on the activity series you'll see

like sodium at the top

aluminum Fe copper hydrogen I mean

before copper you have hydrogen then

copper and then

AG now these are not all of the elements

but this is just some of them the metals

at the top of the activity series are

very reactive the metals at the bottom

like silver or gold they're less

reactive or

non-reactive so because aluminum is

higher than copper on the activity

series that means aluminum is more

reactive than copper so it's strong

enough to displace copper out of the

solution so this reaction will

work so typically in a single

replacement reaction you'll have like a

pure element and a

compound if the metal is above the metal

ion then it's going to work if copper

was above aluminum and if we action it

will not

work now what's the first thing that we

need to do to write the net ionic

equation the first thing is we need to

write the total ionic equation so

everything that's in the aquous phase we

need to separate it into

ions so aluminum which is a solid we're

going to leave it the way it is we're

not going to change it now we have two

aluminum atoms so we got to put the two

in front of

Al now in three

cucl2 we have three copper

ions and we have

six chloride

ions on the right side we have two

aluminum plus three

ions and we have six chloride ions

and we have three copper

atoms so CU and Al is still in a solid

phase all of the ions are in the aquous

phase so this is the total ionic

equation now our next step is to

eliminate the spec to the ions the spec

to the ions are the ions that are found

exactly the same on both sides of the

reaction so the only spect ions that we

have are the chloride ions so now what

remains represents the net ionic

equation so it's going to be two

aluminum atoms in the solid

phas plus three copper

ions in the Aquas

phase and that's going to produce two

aluminum

ions in the a quiz

phase and three copper

atoms single replacement reactions are

redox reactions because the way this

reaction works is by means of a transfer

of

electrons as you can see the aluminum

metal turned into the aluminum plus 3

cation that means that it lost three

electrons so aluminum was

oxidized now the copper plus two ion it

went from plus two to zero

so therefore each copper ion gained two

electrons which means copper was reduced

whenever a substance gain electrons it's

reduction whenever it loses electrons to

oxidation because aluminum was oxidized

it is the reducing agent in a reaction

now because the copper 2 ion was reduced

it is the oxidizing

agent now let's try another example

consider the reaction

between zinc metal and hydrochloric

acid what are the products of this

reaction so first is zinc strong enough

to displace hydrogen out of the solution

will this reaction even

work so below aluminum you have zinc and

then you have

Fe and there's hydrogen copper silver

and gold on the activity series zinc is

above hydrogen so zinc is strong enough

to displace hydrogen out of the solution

so this reaction will work so zinc is

going to pair up with

chlorine zinc as an ion typically has a

plus two

charge and the chloride

ion has a minus one

charge so using the crisscross method

it's going to be

zn1

cl2

now hydrogen is going to be by itself as

a Pure Element hydrogen is a diatomic

element so it exists as

H2 so now we need to balance the

reaction to balance it all we need to do

is put a two in front of

HCL everything else has a one in front

of

it now we need to write the phases so

zinc is a metal it's a solid hydrogen is

a

gas and the other two compounds are

Aquis whenever you have an acid like HCL

most acids dissolve in water so they're

in the aquous phase and zinc chloride is

soluble the only chlorides that are not

soluble are silver lead and Mercury at

least those are the ones you have to

know now that we have a balanced

reaction let's go ahead and write the

total ionic

equation so zinc which is a solid it's

going to stay the way it is and HCL we

have two H+

ions and two chloride

ions so don't forget to distribute the

two now on the right side in zinc

chloride we have the zinc 2+

ion we have also two chloride

ions and we have hydrogen

gas

so what are these spectator ions in this

reaction notice that it's the chloride

ion they appear exactly the same on both

sides so the net ionic equation is what

remains so we have solid zinc

metal plus two H+ ions which is in the

aquous

phase and that's going to produce the

zinc plus two ions

and hydrogen

gas now hydrogen gas is in the gaseous

phase and zinc is in the aquous

phase so that's how you can write the

net iic equation for this particular

single replacement

reaction now on the left side which

substance is oxidized and which one is

reduced zinc was oxidized its oxidation

state increased from0 to

two whenever the oxidation state

increases that means that the element

lost electrons so that's why we could

say zinc was

oxidized and keep in mind the oxidation

state for any Pure Element is always

zero now for hydrogen it went from one

to zero so hydrogen was reduced it's

oxidation number went down it decreased

which means that hydrogen gained

electrons

so the zinc metal is the redu an agent

because it was oxidized and the H+ ion

is the oxidizing agent because it was

reduced metals are usually good reducing

agents these are the active metals the

metals that are on the top of the

activity Series so like sodium magnesium

aluminum they're very good reducing

agents nonmetals like Florine chlorine

they're very good oxidizing agents so

reducing agents they like to give away

electrons oxidizing agents they like to

receive

electrons now what would you do if you

see a reaction that looks like

this chlorine

gas is bubble through a solution of

aquous sodium bromide what's going to

happen what products will be produced in

this reaction and will this reaction

even

work so let's look at the activity

series

for the

halogens Florine is the most reactive

then it's chlorine and then bromine and

then iodine or

iodine so chlorine is above bromine that

means Elemental chlorine can displace

bromide out of the solution so this

reaction will

work so if chlorine displaces bromine

out of the solution that means that

chlorine is going to pair up with

sodium sodium has a plus one

charge chloride as an ion has a negative

1 charge whenever you're write in the

compound the ion with a positive charge

is usually written first now because

these two have the same charge even

though the sign is

different but the magnitude is the same

these two will combine in a one one

ratio so it's na1 cl1 but you don't need

to write the one you can simply write it

as

na now once bromine once the bromide ion

is displaced out of the solution it's

going to turn into Elemental bromine

which is

diatomic so now we need to balance the

reaction so notice that we have two

bromine atoms on the right side so we

got to put a two in front of NAB and we

we have two chlorine atoms on the left

so we need a two in front of

NAC and so now the reaction is

balanced before we can write the net

ionic equation we need to write the

phases for every substance in this

reaction so what's the phase for

chlorine chlorine is a gas so we're

going to put G bromine is a red

liquid now sodium bromide and sodium

chloride these ionic compounds are

soluble all of the group one metal cats

like sodium lithium potassium are

soluble so we're going to put

AQ for these

two so to write the total ionic equation

everything that is in the aquous phase

we need to separate into ions so

chlorine is going to remain the same and

then we're going to have two na+

ions and two bromide ions

on the right side we're going to have

two sodium

cats and two chloride anions A cation is

simply a positively charged ion an anion

is a negatively charged

ion so now what are The Spectator ions

in this

reaction the only thing that doesn't do

anything in this reaction is sodium and

as you can see it looks the same on both

sides of the reaction so now what

remains is the net ionic equation which

is

cl2 plus 2 BR

minus and that turns into two chloride

ions and Elemento

bromine let's not forget to write the

phases in the net ionic

equation so the ions are going to be in

the aquous phase

and so this is it this is the complete

net ionic equation now which element is

the oxidizing agent and which one is the

reducing

agent so the oxidation state for any

Pure Element is zero so chlorine goes

from Z to

1 so it decreased it went down so

chlorine was reduced which means it's

the oxidizing

agent so that means that chlorine it

receive electrons in this

reaction bromide it went from 1 to0 if

you go from 1 to0 on a number line

you're going to the right which means

the value is increasing so the oxidation

state of bromide went up from negative 1

to zero which means that bromide it lost

electrons it was oxidized which makes it

the reducing agent in this

reaction consider this reaction

between iron metal and zinc

chloride so what are the products of

this reaction and will this reaction

work so on the activity series we have

aluminum zinc Fe and hydrogen notice

that the metal Fe is below zinc so Fe is

not strong enough to displace zinc out

of the solution so therefore if you

place iron metal in a solution of zinc

chloride you will observe no

reaction so there's no point in

predicting the products of this reaction

because nothing's going to

happen try this

example sodium metal with hydrochloric

acid what are the products of this

reaction and will it

work sodium is way above hydrogen on the

activity Series so sodium is definitely

strong enough to dis Place hydrogen out

of the

solution so sodium is going to pair up

with

Florine as an ion sodium has a plus one

charge and fluoride has a minus one

charge so these two will combine in a

one: one ratio forming sodium chloride

and hydrogen is going to be displaced

out of the

solution so now our next step is to

balance the reaction so because we have

two h hydrogen atoms on the right side

we need a two in front of

HF and now we have two Florine atoms on

the left so we're going to need a two in

front of any F and a two here as well so

now the reaction is

balanced sodium metal is a

solid H2 is a

gas sodium fluide is soluble because

sodium is an alkaline

metal and alkaline metals are us usually

soluble now what about

HF acids usually dissolve while in water

so HF is going to be in an aquous phase

but HF is a weak acid in the other

example earlier in this video we had HCL

which is a strong acid strong acids

ionize completely but weak acids they

don't ionize very much so therefore even

though HF is

aquous because it doesn't ionize

significantly and the net ionic equation

or in even in the total ionic equation

you should not separate HF into its ions

because it's a weak acid and it doesn't

ionize

completely so the only one that we're

going to separate into ions is sodium

floride that's what you have to be

careful with in this particular problem

so let's write the total ionic equation

so it's 2 na plus 2 HF so that's going

to stay the

same now this part we're going to break

it into ions so we're going to have two

na+

ions two fluide

ions and H2

gas so notice that there are no speced

ions in this reaction everything is

different on both sides of the equation

therefore this is one of those rare

cases in which the total ionic equation

is the same as the net ionic equation so

this is the

answer now don't forget to put the

phases sodium is in a solid phase

hydrogen is in the gaseous phase HF is

aquous and the other two ions are in

aquous

phases sodium metal is the reducing

agent it was oxidized from0 to+ one HF

is the oxidizing agent the hydrogen in

HF went from + one to zero so HF was

reduced so that is it for this video

thanks for watching and have a great day