Chemical Reactions
These are the substances present at the start of a chemical reaction.
What are reactants?
This law states that matter is not created or destroyed during a chemical reaction.
What is the law of conservation of mass?
This gas is needed for combustion.
What is oxygen?
This scale measures how acidic or basic a substance is
What is the pH scale?
This describes how fast a chemical reaction occurs.
What is reaction rate?
These are the new substances formed during a chemical reaction.
What are products?
During a chemical reaction, atoms do this rather than being created or destroyed.
What is rearrange?
This is another common word for combustion and involves the presence of a flame
What is burning?
A substance with a pH of 3 belongs to this category.
What is an acid?
Increasing temperature usually has this effect on reaction rate.
What is increases the reaction rate?
This symbol separates the reactants from the products in a chemical equation.
What is an arrow?
These numbers are placed in front of chemical formulas to balance equations.
What are coefficients?
This happens to the mass of steel wool when it reacts with oxygen
What is increases?
This pH value is neutral.
What is 7?
At higher temperatures, particles do this faster.
What is move?
In HCl + NaOH → NaCl + H₂O, these substances are the products.
What are NaCl (sodium chloride) and H₂O (water)?
This must be the same for each element on both sides of a balanced chemical equation
What is the number of atoms?
This gas turns limewater cloudy during the candle combustion investigation
What is carbon dioxide?
This is the name of a reaction between an acid and a base
What is neutralisation?
This theory explains how particle collisions affect reaction rate.
What is collision theory?
During a chemical reaction, these are broken and/or formed as atoms rearrange
What are chemical bonds?
These numbers must never be changed when balancing a chemical equation because they are part of the chemical formula
What are subscripts?
Steel wool gains mass when burned because it combines with atoms of this element
What is oxygen?
As an acid is successfully neutralised, its pH moves towards this value.
What is 7?
Higher temperatures cause more of these to occur each second, increasing reaction rate
What are successful collisions?