Chemical Changes Flashcards

Flashcards about chemical changes based on lecture notes.

What happens to atoms during chemical creations?

Atoms rearrange to form new products; they are neither created nor destroyed, and mass is conserved.

What is a key difference between Physical and Chemical changes?

Physical changes do not form new substances whereas chemical changes do.

Are chemical changes easily reversible?

No, chemical changes are usually irreversible.

What are the components of a word equation representing a chemical change?

Reactant(s) ----condition(s)----> Product(s)

What is conserved during a chemical reaction?

Mass is conserved.

What is combustion?

A chemical reaction in which a substance is heated in the presence of oxygen to form one or more new substances.

Name three real-world applications of combustion.

Cooking, transport, and generating electrical energy.

What happens during Thermal Decomposition?

A substance breaks down into two or more simpler substances upon heating.

What is oxidation?

When a substance gains oxygen, it undergoes a chemical change called oxidation.

Define cellular respiration.

A chemical process in which living cells of plants and animals take in oxygen to release the energy stored in glucose.

What happens when an acid is mixed with an alkali?

Neutralisation occurs.

What are the products of the chemical reaction between acids and alkalis?

Salt and Water

What are the products of the chemical reaction between acids and metals?

Salt and Hydrogen

What is the test for hydrogen gas?

Lighted splint extinguishes with a POP sound.

What are the products of the chemical reaction between acids and metal carbonates?

Salt, Carbon dioxide, and Water

What is the test for carbon dioxide gas?

Water precipitate forms in limewater.

What is the pH scale used for?

It is a measure of how acidic or alkaline a substance is.

Describe how indicators will behave in acidic and alkaline conditions.

Indicators will change colours in the presence of an acid or an alkali so we can use them to identify if an unknown is an acid or alkali

Give three applications of Neutralisations.

Antacids, Soil treatment, Toothpaste

Name three ways chemical changes can occur.

Mixing, Heating, Exposure to Light

Define Photosynthesis.

Photosynthesis is the process in which green plants make food in the presence of light.

What is Electroplating?

Electroplating is the process in which a substance is coated with a metal with the passage of an electric current.

Other than improving appearance, what other purposes does electroplating serve?

The metal layer may also prevent them from rusting

Describe how knowledge of chemical reactions help us in cooking.

Causes chemical reactions in food, softens food and improves flavour

How does knowledge of chemical reactions help us in respiration?

Allow cells in an organism to survive and reproduce; Is an important process that releases energy

How does knowledge of chemical reactions help us in decay?

Process of breaking down organic matter into simpler substances; Allows nutrients to be returned to environment

How can scientists prevent rusting?

Coating an iron rod with paint; Oiling an iron chain; Coating iron with a layer of zinc during galvanising; Keeping iron objects dry in an oven

Name three air pollutants produced by fuel combustion.

Carbon Monoxide, Sulfur Dioxide, Oxides of Nitrogen

What is ocean acidification?

Result of chemical reactions arising from human activities; Causes serious problems for marine life