All Flashcards
What happens in a combustion reaction?
A hydrocarbon reacts with oxygen to produce carbon dioxide and water, releasing a lot of energy.
What happens when a limiting reactant is completely used up?
The reaction stops, and the amount of product formed is limited by the amount of the limiting reactant.
What happens during neutralization?
An acid and a base react to form a salt and water.
What is the effect of increase in oxidation number?
Oxidation (loss of electrons).
What is the effect of decrease in oxidation number?
Reduction (gain of electrons).
What are the steps to write net ionic equations?
- Write the balanced molecular equation. 2. Dissociate all aqueous compounds into ions. 3. Identify and cancel out spectator ions. 4. Write the final net ionic equation with only the reacting species.
What are the steps to balance chemical equations?
- Write out the unbalanced equation. 2. Start by balancing elements that appear in only one compound on each side. 3. Balance polyatomic ions as a single unit if they appear unchanged on both sides. 4. Balance hydrogen and oxygen last. 5. Double-check that all atoms and charges are balanced.
How to assign oxidation numbers?
- Elemental form = 0. 2. Monatomic ion = charge. 3. Oxygen = -2 (except in peroxides). 4. Hydrogen = +1 (except with metals). 5. Sum = 0 (neutral compound) or charge (polyatomic ion).
What are the differences between physical and chemical changes?
Physical: Changes in intermolecular forces, no change in composition (e.g., melting ice). Chemical: Changes in intramolecular bonds, new substances formed (e.g., burning wood).
What are the differences between acids and bases according to the Brønsted-Lowry definition?
Acids: Proton (H⁺) donors. Bases: Proton (H⁺) acceptors.
What are the differences between Oxidation and Reduction?
Oxidation: Loss of electrons (oxidation number increases). Reduction: Gain of electrons (oxidation number decreases).
What is the difference between endpoint and equivalence point?
Endpoint: The point in a titration where a color change is observed, usually indicated by an indicator. Equivalence Point: The point where the moles of titrant added are equal to the moles of analyte.