Lesson video

Hello.

My name is Mrs. Collins and I'm going to be taking you through the learning today.

This lesson forms part of the unit Industrial Chemistry and is called Industrial Equilibrium, The Contact Process.

During today's lesson, you will describe the Contact process for the production of sulfuric acid, explain the importance of each step, and describe the conditions used.

Here are the key words for today's lesson, raw material, feedstock, contact process, exothermic, and corrosive.

Pause the video here, read through those explanations, and make any notes you feel you need to.

Today's lesson is split into two separate parts.

Part one is the Introduction to the Contact process and part two, Practical applications and hazards.

So let's start on part one, Introduction to the Contact process.

The contact process is an industrial method for producing sulfuric acid, a key chemical in many industrial applications.

It was developed in the 19th century and involves multiple steps and specific conditions to efficiently produce sulfuric acid.

Sulfuric acid is manufactured using sulphur, oxygen, and water.

The raw materials, sulphur, is usually sourced from the earth's crust or obtained as a byproduct of refining fossil fuels.

Oxygen is abundant and sourced from the air.

Water is essential for the final production stages.

Here is a question based on the learning so far.

Sulphur and oxygen are the raw materials used to make sulfuric acid.

Is this true or false? And justify your answer using the statements below.

Pause the video here, answer the question, and I'll see you when you're finished.

Welcome back.

The answer to the question is true.

Sulphur is sourced from the Earth's crust and oxygen is naturally abundant in the air.

Well done if you got that correct.

A series of reactions shows how sulphur dioxide is first produced, and then converted to sulphur trioxide, then finally used to produce sulfuric acid.

Step one, making the sulphur dioxide.

This can be made by burning sulphur in excess oxygen.

Here is the equation for the reaction.

You can see there we've got sulphur plus oxygen, forming sulphur dioxide.

And remember, excess oxygen means there's more oxygen than is needed for the reaction to take place, and therefore oxygen will not be the limiting reactant.

Sulphur will be the limiting reactant.

Or by heating sulphide ores in excess oxygen, e.

g.

a copper smelter.

So here, we've got copper sulphide plus oxygen forming copper and sulphur dioxide.

This means the sulphur dioxide is already mixed with oxygen ready for the next step.

Step two is the reversible reaction between sulphur dioxide and oxygen to make sulphur trioxide.

So, here's the equation for the reaction.

So, we've got two moles of sulphur dioxide, reacting with one mole of oxygen, to form two moles of sulphur trioxide.

And the temperature required is 450 degrees Celsius, a pressure of 1 to 2 atmospheres, and a catalyst is also added vanadium oxide.

These conditions are optimised to ensure efficient production of sulphur trioxide.

Here is a question based on that learning.

What is the balanced equation for the equilibrium step of the contact process? So, look carefully through those equations.

Decide which one is correct.

Pause the video here, I'll see you when you're finished.

Welcome back.

So, the correct answer is c.

Well done if you got that correct.

Here is the second question based on that learning.

What are the optimal conditions for the equilibrium in the contact process in terms of temperature and pressure? Pause the video here, answer the question, and I'll see you when you're finished.

Welcome back.

So, the answer is c, 450 degrees Celsius and 1 to 2 atmospheres.

So, well done if you've got that correct.

Step three, convert sulphur trioxide into sulfuric acid.

Now, directly adding sulphur trioxide to water is a highly exothermic chemical reaction and it creates dangerous clouds of sulfuric acid.

To minimise those risks, sulphur trioxide is added to concentrated sulfuric acid forming a corrosive liquid called oleum.

And here's the equation for that reaction.

Water is then added to the oleum to safely produce sulfuric acid, and there's the equation for that reaction.

Here's a question based on that learning.

Directly adding sulphur trioxide to water is highly exothermic.

Is that true or false? And justify your answer using the statements below.

Pause the video here and I'll see you when you've finished.

Welcome back.

So, the answer is true.

To minimise the risks, sulphur trioxide is added to concentrated sulfuric acid to form oleum.

So, well done if you've got that correct.

We are now going to complete task A.

What I'd like you to do is fill in the blanks using the words, phrases, the numbers from that table.

Pause the video here, answer the question, and I'll see you when you're finished.

Welcome back.

So, let's have a look at the answers to that.

So in a reversible reaction, the desired product needs to be continuously removed from the reaction.

Sulphur is a raw material in the industrial production of sulfuric acid.

SO2 is produced by reacting oxygen with sulphur.

In industry, the contact process is typically performed at 2 atmospheres, 450 degrees Celsius, and with a vanadium oxide catalyst.

So, well done if you got that correct.

We're now moving on to part two of the lesson, Practical applications and hazards.

Sulfuric acid is one of the highest-volume industrial chemicals produced worldwide.

Globally, over 230 million metric tonnes of sulfuric acid are produced annually.

And here's an example of a reactor for producing sulphur from H2S.

The global market was valued at approximately 10 billion pounds in 2020, and this value is projected to grow due to increasing demand in sectors such as agriculture, manufacturing, and chemical processing.

Sulfuric acid is a vital chemical in many industries due to its versatility.

It's essential in the production of fertilisers such as ammonium sulphate, which supports plant growth.

Other uses include car battery acid, as a feedstock, industrial cleaning agent, and a catalyst in many organic chemical reactions.

Here's a question based on that learning.

Why is sulfuric acid production considered a major industrial process? So pause the video here, answer the question, and I'll see you when you're finished.

Welcome back.

So, the answer to the question is it has significant economic implications.

So, well done if you got that correct.

Here's a follow-up question.

So, sulfuric acid is used for, so pause the video here, answer the question, and I'll see you when you're finished.

Welcome back.

So hopefully, you recognise it's a little bit of a trick question because sulfuric acid is used for all of those processes.

So, well done if you got that correct.

Sulfuric acid is highly corrosive.

It means it can cause severe burns on contact with the skin or the eyes.

When heated or mixed with certain chemicals, it releases toxic fumes.

Mixing sulfuric acid with water can generate a significant amount of heat, making it extremely dangerous.

And its release into the atmosphere contributes to acid rain, which can have a detrimental impact on the environment.

And look carefully at those two symbols.

So, the first symbol there shows a corrosive substance, and the second symbol shows toxic substance.

Sulfuric acid production has significant environmental impacts that need to be managed.

The contact process is energy intensive, which contributes to global carbon emissions.

Scrubbers and catalytic converters reduce the emissions and minimise environmental impact.

Efforts to increase efficiency are crucial to reducing the carbon footprint of sulphur acid production.

And here's an example of a scrubber being installed in a ship to reduce the emission of sulphur dioxide.

Sulfuric acid is a powerful dehydrating agent capable of removing water from various substances.

So, concentrated sulfuric acid removes water from glucose leaving behind pure carbon, which is what you can see happening in the beaker here.

This is a highly exothermic reaction and produces steam and forms a black carbon structure at the end, which is what you can see forming.

Here's a question based on that learning.

Sulfuric acid production significantly contributes to global carbon dioxide emissions.

Is that true or false? Justify your answer.

Pause the video here, answer the question, and I'll see you when you're finished.

Welcome back.

So, the answer to that question is true.

These processes release significant amounts of CO2, contributing to global emissions.

Well done if you've got that correct.

Follow up question.

Select all the correct statements about sulfuric acid.

So, read through those carefully.

Pause the video here, answer the question, and I'll see you when you're finished.

Welcome back.

So, let's go through the answers.

It requires high temperatures and specific pressures in its production, and it significantly contributes to global energy consumption.

So, well done if got that correct.

We are now going to complete Task B.

Some students are discussing the contact process.

Identify who is correct and update any incorrect statements.

So, what you're going to do is pause the video.

You're going to read through each of those individual statements, decide if they're correct or not, and if they're incorrect, you need to change the statements to make them correct.

So, pause the video here and I'll see you when you're finished.

Welcome back.

So, let's have a look at each of those statements individually.

So, Andeep has said that, "Sulfuric acid is highly corrosive and can cause severe burns on contact with the skin." That's correct.

Lucas has suggested that, "Sulfuric acid is produced in small quantities and has limited industrial applications." This is incorrect.

Sulfuric acid is one of the highest-volume industrial chemicals produced worldwide, and is vital to many different industries.

Sofia has said, "The Contact Process is energy efficient and does not significantly contribute to global carbon emissions." This is incorrect.

The contact process is energy-intensive and contributes significantly to global carbon emissions.

And Laura said, "Sulfuric acid is essential for the production of some fertilisers, car batteries, and dyes." And this is correct.

So, well done if you got that answer correct.

Here is a summary of today's lesson.

The contact process involves the production of sulphur trioxide from sulphur dioxide using a catalyst.

The process includes three main stages, burning sulphur or sulphide ores to produce SO2, converting SO2 to SO3, and then converting SO3 to sulfuric acid.

The conversion of SO2 to SO3 is a reversible reaction performed at 1 to 2 atmospheres and 450 degrees Celsius using a vanadium oxide catalyst.

Sulfuric acid production is energy intensive and releases large amounts of carbon dioxide contributing to global emissions.

The production of sulfuric acid is vital for various industries, including fertiliser production, chemical manufacturing, and petrol refining.

Thank you very much for joining me for today's lesson.