Chemical formulae and conservation of mass

Define conservation of mass and apply this chemical equation.

Chemical formulae and conservation of mass

Define conservation of mass and apply this chemical equation.

Lesson details

Key learning points

  1. Interpret chemical formulae
  2. Apply conservation of mass to equations

Equipment

Periodic table

Licence

This content is made available by Oak National Academy Limited and its partners and licensed under Oak’s terms & conditions (Collection 1), except where otherwise stated.

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6 Questions

Q1.
What is the chemical formula for carbon dioxide?
CO formula
Correct answer: CO2 formula
C2O formula
2CO formula
Q2.
Which statement is correct about the formula below?
There are two potassium atoms, four sulfur atoms and four oxygen atoms.
Correct answer: There are two potassium atoms, one sulfur atom and four oxygen atoms.
There is one potassium atom, one sulfur atom and four oxygen atoms.
There is one potassium atom, two sulfur atoms and four oxygen atoms.
Q3.
Matter can be solid, liquid or gas. Oxygen is a at room temperature.
Correct Answer: gas, gases
Q4.
What is the mass of an object?
How compact the particles are within the object.
The amount of space the object occupies.
The force acting on the object due to gravity.
Correct answer: The measure of the amount of matter in the object.
Q5.
100 g of ice cream melts. What is the mass of the liquid ice cream?
Correct Answer: 100 g, one hundred grams, 100 grams
Q6.
60 g of calcium reacts with 50 g of oxygen. How many grams of calcium oxide are produced?
10 g
Correct answer: 110 g
50 g
60 g

6 Questions

Q1.
How many atoms of sulfur are present in the formula below?
Correct answer: 1
2
3
4
Q2.
The law of conservation of mass states ...
the number of atoms in the reactants is always more than the number of atoms in the products.
Correct answer: the number of atoms in the reactants is equal to the number of atoms in the products.
the number of atoms/mass of reactants can be more or less than the atoms/mass of the product.
Correct answer: the total mass of the reactants is equal to the total mass of the products.
the total mass of the reactants is more than the total mass of the products.
Q3.
20 g of oxygen reacts with 15.5 g of lithium. How many grams of lithium oxide are produced?
15.5 g
20.0 g
Correct answer: 35.5 g
4.5 g
Q4.
Aluminium oxide breaks down into aluminium and oxygen. If the reaction takes place on a balance, the mass appears to...
Correct answer: decrease because a gas was produced.
decrease because one of the reactants was a gas.
increase because a gas was produced.
increase because one of the reactants was a gas.
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
Correct answer: Si(OH)3
Si3OH
SiO3H3
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
Correct answer: 4 Fe + 3 O2 → 2 Fe2O3
3 Fe + 3 O2 → 2 Fe2O3

Lesson appears in

UnitChemistry / Atomic structure and the periodic table

Chemistry

UnitCombined science / Atomic structure and the periodic table