Year 11 Science: Acids and Bases Flashcards

Flashcards for Year 11 Science: Acids and Bases, covering foundational chemistry concepts and reactions.

Element

A pure substance made up of only one type of atom.

Positive Ion (Cation)

Formed when an atom loses an electron.

Negative Ion (Anion)

Formed when an atom gains an electron.

Ionic Bonding

The force of attraction that holds ions together in an ionic substance, occurring when a metal reacts with a non-metal by transferring electrons.

Reaction Rate

How fast a chemical reaction occurs.

Catalyst

Substance that speeds up a reaction without being used up, by lowering activation energy.

Acid

Forms acidic solutions in water and produces H+/hydrogen ions.

Base

Substance that produces OH-/hydroxide ions that reacts with acids and neutralises them.

Alkali

Water-soluble bases that form alkaline (basic) solutions.

Neutralisation Reaction

Reaction between an acid and a base (alkali), where H+ and OH- ions combine to form water.

Metal Oxide

Compound containing a metal and oxygen (O2-).

Metal Hydroxide

Compound containing a metal and hydroxide (OH-).

Metal Carbonate

Compound containing a metal and carbonate (CO3 2-).

Metal Hydrogen Carbonate

Compound containing a metal and hydrogen carbonate (HCO3 -).

Particle theory

“All matter is made up of tiny particles which are constantly in motion”

Collision Theory

“Moving particles are constantly colliding with each other, but not all collisions result in reaction because particles must collide with sufficient activation energy and at the correct orientation”. 

How can reaction rates can be measured

 by finding out how quickly reactants are used up or how quickly products are formed.

Why does the rate of a chemical reaction changes over time

Reactions are usually fastest at the beginning (steep line) when the concentration of reactants is greatest. Reactions slow down after a period of time as the concentration of reactants decreases, therefore there are less frequent collisions. When the line becomes horizontal, the reaction has stopped because either one or both reactants have been used up.

What is the effect of catalysts on reaction rates

Catalysts are substances that speed up reactions without itself being used up. They do so by lowering activation energy by providing an alternate pathway for reaction therefore more collisions will have enough energy to initiate a reaction and help reactant particles line up the right way for collisions. 

How does temperature, concentration and surface area affect reaction rates

Temperature (raising temperature increases the rate of reaction as it causes reactant particles to move quickly, as there is more kinetic energy and causes a higher chance of collisions)

Concentration (increasing concentration increases the rate of reaction as reactant particles are more numerous/closer together causing an increased chance of collisions)

Surface Area (increasing surface area of reactant exposes more particles and leads to a increased reaction rate as more particles are able to collide)