Reactions Flashcards
Give common examples of gas producing chemical reactions using
simple word equations.
Vinegar and Baking Soda Reaction:
Equation: Vinegar + Baking Soda → Carbon Dioxide + Water + Sodium Acetate
Example: Acetic Acid + Sodium Bicarbonate → Carbon Dioxide + Water + Sodium Acetate
Name a few common compounds, and their formulas
Water (H₂O):
Common Compound: Water
Formula: H₂O
Carbon Dioxide (CO₂):
Common Compound: Carbon Dioxide
Formula: CO₂
Sodium Chloride (NaCl):
Common Compound: Table Salt
Formula: NaCl
Hydrochloric Acid (HCl):
Common Compound: Hydrochloric Acid
Formula: HCl
Sodium Bicarbonate (NaHCO₃):
Common Compound: Baking Soda
Formula: NaHCO₃
Methane (CH₄):
Common Compound: Methane (Natural Gas)
Formula: CH₄
Oxygen (O₂):
Common Compound: Oxygen
Formula: O₂
Hydrogen Peroxide (H₂O₂):
Common Compound: Hydrogen Peroxide
Formula: H₂O₂
Calcium Carbonate (CaCO₃):
Common Compound: Limestone or Chalk
Formula: CaCO₃
Ammonia (NH₃):
Common Compound: Ammonia
Formula: NH₃
Define corrosion
Corrosion is a chemical reaction in which a metal reacts with oxygen.
The most common and most costly form of corrosion
is rusting.
List ways in which rusting can be prevented
- coating
- galvanising
- alloying
What is a combustion?
Combustion is a chemical reaction in which a fuel is burnt in the presence
of Oxygen to produce Carbon Dioxide & Water.
State the word equation for corrosion & combustion
Corrosion
Corrosion, particularly the rusting of iron, is a common type of corrosion.
Word Equation for Rusting:
Iron + Oxygen + Water → Iron Oxide (Rust)
Combustion
Combustion is the process of burning a substance in the presence of oxygen.
Word Equation for the Combustion of Methane:
Methane + Oxygen → Carbon Dioxide + Water
Word Equation for the Combustion of Wood (simplified):
Wood + Oxygen → Carbon Dioxide + Water
State where the chemical potential energy released
from a reaction is stored.
The chemical potential energy released from a reaction is stored in the bonds between the atoms of the reactants.
During a chemical reaction, these bonds are broken and new bonds are formed to create the products.
The energy stored in the chemical bonds of the reactants is transformed and released in various forms, such as:
- Heat: Most commonly, the released energy increases the thermal energy of the surroundings, making the surroundings warmer.
- Light: In some reactions, energy is released as light, such as in combustion or certain biochemical reactions (e.g., bioluminescence).
- Sound: Some reactions release energy in the form of sound, as heard in explosions.
- Electrical Energy: In electrochemical reactions, such as those in batteries, the energy is stored as electrical energy and can be used to do electrical work.
In summary, the chemical potential energy stored in the bonds of the reactants is transformed into other forms of energy during the reaction, depending on the nature of the reaction and the products formed.
State what the symbol (arrow) refers to in a chemical
reaction.
In a chemical reaction, the arrow (→) refers to the direction of the reaction, indicating that the reactants on the left side are transformed into the products on the right side. It can be read as “yields,” “produces,” or “forms.”
Example:
Reactants
→
Products
Reactants→Products
For instance, in the combustion of methane:
Methane + Oxygen
→
CarbonDioxide + Water
Methane+Oxygen→CarbonDioxide+Water
In this example, methane and oxygen are the reactants, and carbon dioxide and water are the products. The arrow shows that the reactants react to form the products.
List the five principles of the atomic theory of
matter suggested by John Dalton
John Dalton’s atomic theory, proposed in the early 19th century, laid the foundation for our modern understanding of atomic structure. Here are the five key principles of Dalton’s atomic theory:
-
All matter is composed of atoms:
- Atoms are the indivisible and indestructible building blocks of matter. (Note: Modern science has found that atoms can be divided into subatomic particles, but they are still considered the fundamental units of chemical elements.)
-
All atoms of a given element are identical in mass and properties:
- Atoms of the same element have the same size, mass, and chemical properties. (Note: Isotopes, which are atoms of the same element with different masses, were discovered later.)
-
Compounds are formed by a combination of two or more different kinds of atoms:
- Atoms of different elements can combine in fixed ratios to form compounds. Each compound has a specific combination and proportion of atoms.
-
A chemical reaction is a rearrangement of atoms:
- Chemical reactions involve the rearrangement of atoms to form new compounds. The atoms themselves are not changed in a chemical reaction; only their arrangements and bonds are altered.
-
Atoms cannot be created or destroyed in a chemical reaction:
- The total number of atoms of each element remains the same before and after a chemical reaction, reflecting the conservation of mass.
These principles provided a systematic explanation of chemical reactions and the behavior of matter at the atomic level, significantly advancing the field of chemistry.
Recall the word equation for the corrosion of iron
The word equation for the corrosion of iron, specifically rusting, is:
Iron+Oxygen+Water→IronOxide(Rust)
State whether or not atoms can be created and
destroyed during a chemical reaction.
Atoms cannot be created or destroyed during a chemical reaction. This principle is known as the law of conservation of mass. During a chemical reaction, atoms are rearranged to form new substances, but the total number of each type of atom remains the same before and after the reaction. Thus, the mass of the reactants equals the mass of the products.
Explain what happens to the atoms during a
chemical change
During a chemical change, the atoms involved undergo a process of rearrangement to form new substances. Here’s what happens in detail:
Breaking of Bonds: The chemical bonds between atoms in the reactants are broken. This requires energy to overcome the forces holding the atoms together.
Formation of New Bonds: After the bonds in the reactants are broken, the atoms are free to interact and form new bonds. These new bonds create the products of the reaction.
Rearrangement of Atoms: The atoms are reorganized into different structures, leading to the formation of new compounds. The way the atoms are bonded together changes, resulting in new molecular configurations.
Energy Changes: During the breaking and forming of bonds, energy is either absorbed or released. If the energy released in forming new bonds is greater than the energy required to break the old bonds, the reaction is exothermic (releases energy). If more energy is required to break the bonds than is released when new bonds are formed, the reaction is endothermic (absorbs energy).
Explain the difference between reactants and
products.
The difference between reactants and products lies in their roles and positions in a chemical reaction:
Reactants:
Definition: Reactants are the starting substances that undergo a chemical change in a reaction.
Position in a Chemical Equation: Reactants are written on the left side of the arrow in a chemical equation.
Characteristics: They have their own distinct properties before the reaction occurs. Reactants are consumed during the reaction.
Products:
Definition: Products are the new substances formed as a result of the chemical reaction.
Position in a Chemical Equation: Products are written on the right side of the arrow in a chemical equation.
Characteristics: They have different properties from the reactants. Products are generated by the rearrangement of atoms and bonds in the reactants.
Difference between reactants and products?
Reactants are the substances that start a chemical reaction and are consumed during the process.
Products are the substances formed as a result of the chemical reaction and are produced by the rearrangement of atoms from the reactants.
Explain why iron structures need protection from
corrosion while aluminium structures do not.
Iron needs protection from corrosion because it rusts easily when exposed to moisture and oxygen.
Aluminum does not need as much protection because it forms a natural protective oxide layer that prevents further corrosion.
