Chemical formulae and conservation of mass

Define conservation of mass and apply this chemical equation.

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Quiz:

Intro quiz - Recap from previous lesson

Before we start this lesson, let’s see what you can remember from this topic. Here’s a quick quiz!

Q1.What is the chemical formula for carbon dioxide?

CO formula

CO2 formula

C2O formula

2CO formula

1/6

Q2.Which statement is correct about the formula below? K2SO4

There is one potassium atom, two sulfur atoms and four oxygen atoms.There are two potassium atoms, four sulfur atoms and four oxygen atoms.There is one potassium atom, one sulfur atom and four oxygen atoms.There are two potassium atoms, one sulfur atom and four oxygen atoms.

2/6

Q3.Matter can be solid, liquid or gas. Oxygen is a at room temperature.

Fill in the blank.

3/6

Q4.What is the mass of an object?

The force acting on the object due to gravity.The measure of the amount of matter in the object.How compact the particles are within the object.The amount of space the object occupies.

4/6

Q5.100 g of ice cream melts. What is the mass of the liquid ice cream?Answer:

5/6

Q6.60 g of calcium reacts with 50 g of oxygen. How many grams of calcium oxide are produced?

10 g50 g60 g110 g

6/6

This quiz includes images that don't have any alt text - please contact your teacher who should be able to help you with an audio description.

Quiz:

Intro quiz - Recap from previous lesson

Before we start this lesson, let’s see what you can remember from this topic. Here’s a quick quiz!

Q1.What is the chemical formula for carbon dioxide?

CO formula

CO2 formula

C2O formula

2CO formula

1/6

Q2.Which statement is correct about the formula below? K2SO4

2/6

Q3.Matter can be solid, liquid or gas. Oxygen is a at room temperature.

Fill in the blank.

3/6

Q4.What is the mass of an object?

The force acting on the object due to gravity.The measure of the amount of matter in the object.How compact the particles are within the object.The amount of space the object occupies.

4/6

Q5.100 g of ice cream melts. What is the mass of the liquid ice cream?Answer:

5/6

Q6.60 g of calcium reacts with 50 g of oxygen. How many grams of calcium oxide are produced?

10 g50 g60 g110 g

6/6

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This quiz includes images that don't have any alt text - please contact your teacher who should be able to help you with an audio description.

Quiz:

Chemical formulae and conservation of mass

Don’t worry if you get a question wrong! Forgetting is an important step in learning. We will recap next lesson.

Q1.How many atoms of sulfur are present in the formula below? Li2SO4

1234

1/6

Q2.The law of conservation of mass states ...

Select two (2) boxes

the number of atoms in the reactants is equal to the number of atoms in the products.the number of atoms in the reactants is always more than the number of atoms in the products.the total mass of the reactants is more than the total mass of the products.the total mass of the reactants is equal to the total mass of the products.the number of atoms/mass of reactants can be more or less than the atoms/mass of the product.

2/6

Q3.20 g of oxygen reacts with 15.5 g of lithium. How many grams of lithium oxide are produced?

4.5 g15.5 g20.0 g35.5 g

3/6

Q4.Aluminium oxide breaks down into aluminium and oxygen. If the reaction takes place on a balance, the mass appears to...

decrease because a gas was produced.increase because a gas was produced.decrease because one of the reactants was a gas.increase because one of the reactants was a gas.

4/6

Q5.A substance contains one silicon atom, three hydrogen atoms and three oxygen atoms. The hydrogen and oxygen form hydroxide ions. What is the correct formula?

3SiOH

Si(OH)3

Si3OH

SiO3H3

5/6

Q6.What is the correct balanced equation for iron (Fe) reacting with oxygen to form iron oxide?

Fe + O2 → Fe2O3

2 Fe + 3 O → Fe2O3

4 Fe + 3 O2 → 2 Fe2O3

3 Fe + 3 O2 → 2 Fe2O3

6/6

This quiz includes images that don't have any alt text - please contact your teacher who should be able to help you with an audio description.

Quiz:

Chemical formulae and conservation of mass

Don’t worry if you get a question wrong! Forgetting is an important step in learning. We will recap next lesson.

Q1.How many atoms of sulfur are present in the formula below? Li2SO4

1234

1/6

Q2.The law of conservation of mass states ...

Select two (2) boxes

2/6

Q3.20 g of oxygen reacts with 15.5 g of lithium. How many grams of lithium oxide are produced?

4.5 g15.5 g20.0 g35.5 g

3/6

Q4.Aluminium oxide breaks down into aluminium and oxygen. If the reaction takes place on a balance, the mass appears to...

decrease because a gas was produced.increase because a gas was produced.decrease because one of the reactants was a gas.increase because one of the reactants was a gas.

4/6

Q5.A substance contains one silicon atom, three hydrogen atoms and three oxygen atoms. The hydrogen and oxygen form hydroxide ions. What is the correct formula?

3SiOH

Si(OH)3

Si3OH

SiO3H3

5/6

Q6.What is the correct balanced equation for iron (Fe) reacting with oxygen to form iron oxide?

Fe + O2 → Fe2O3

2 Fe + 3 O → Fe2O3

4 Fe + 3 O2 → 2 Fe2O3

3 Fe + 3 O2 → 2 Fe2O3

6/6

Lesson summary: Chemical formulae and conservation of mass

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This was the final lesson in the unit Atomic structure and the periodic table.

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