Chemical Reactions Flashcards
(16 cards)
What is a chemical reaction?
A chemical process where substances change into new substances with energy changes (heat, light, sound, etc.).
What are two types of energy change in chemical reactions?
- Absorbing energy (e.g., cooking food)
- Releasing energy (e.g., burning wood)
What affects the speed of a chemical reaction?
Reactions can be slow (rusting) or fast (burning rocket fuel). Body reactions like breaking down hydrogen peroxide can occur 10,000 times per second.
What are the three parts of a chemical equation?
- Reactants
- Products
- Arrow showing direction (Reactants ➜ Products)
What do the states of matter in equations mean?
(s) = solid
(l) = liquid
(g) = gas
(aq) = aqueous (dissolved in water)
What is a coefficient in a chemical equation?
A whole number in front of a formula showing how many molecules or atoms take part.
Example: Mg + 2HCl ➜ MgCl₂ + H₂
What is the Law of Conservation of Mass?
Mass is conserved in reactions. Atoms are not created/destroyed, only rearranged and bonds are broken/form in new ways.
Name 6 types of chemical reactions.
- Synthesis (A + B ➜ AB)
- Decomposition (AB ➜ A + B)
- Single Displacement (AB + C ➜ AC + B)
- Double Displacement (AB + CD ➜ AD + CB)
- Acid-Base (Acid + Base ➜ Salt + Water)
- Combustion (Fuel + O₂ ➜ CO₂ + H₂O)
What happens in a synthesis reaction?
Two or more substances combine to form one new substance.
Example: 2H₂ + O₂ ➜ 2H₂O
What happens in a decomposition reaction?
One substance breaks into simpler parts.
Example: 2H₂O ➜ 2H₂ + O₂
What happens in a single displacement reaction?
A more reactive element replaces a less reactive one.
Example: Fe + CuSO₄ ➜ FeSO₄ + Cu
What happens in a double displacement reaction?
Two compounds swap elements.
Example: AgNO₃ + NaCl ➜ AgCl + NaNO₃
