C4- Chemical Changes Flashcards
What is a chemical change?
A chemical change is a process where substances transform into different substances with new chemical properties.
True or False: A chemical change can be reversed easily.
False
Fill in the blank: A chemical change often involves the formation of _____ or _____.
gas, precipitate
What are the signs of a chemical change?
Signs include color change, gas production, temperature change, and formation of a precipitate.
Which of the following is a chemical change? (a) Ice melting (b) Iron rusting (c) Water boiling
b) Iron rusting
What is the law of conservation of mass in relation to chemical changes?
The law states that mass is neither created nor destroyed in a chemical reaction.
True or False: Chemical changes can only occur in liquids.
False
What is a reactant?
A reactant is a substance that undergoes change during a chemical reaction.
What is a product in a chemical reaction?
A product is a substance that is formed as a result of a chemical reaction.
Give an example of a physical change.
Melting ice is an example of a physical change.
What is combustion?
Combustion is a chemical change that occurs when a substance reacts with oxygen to produce heat and light.
What is oxidation?
Oxidation is a chemical change where a substance loses electrons, often associated with the reaction of oxygen.
Fill in the blank: A _____ reaction is a type of chemical change where two or more substances combine to form a single product.
synthesis
What is decomposition in chemical terms?
Decomposition is a chemical change where a single compound breaks down into two or more simpler substances.
True or False: All chemical changes result in a temperature change.
False
What role do catalysts play in chemical changes?
Catalysts speed up chemical reactions without being consumed in the process.
What is an endothermic reaction?
An endothermic reaction is a chemical change that absorbs heat from its surroundings.
What is an exothermic reaction?
An exothermic reaction is a chemical change that releases heat to its surroundings.
Which type of reaction involves the exchange of ions between two compounds?
Double displacement reaction
What is a precipitate?
A precipitate is a solid that forms and settles out of a liquid mixture during a chemical reaction.
True or False: Chemical changes can alter the physical properties of a substance.
True
What is a polymerization reaction?
A polymerization reaction is a chemical change where small molecules combine to form a larger, more complex structure.
What is the difference between a physical change and a chemical change?
A physical change does not alter the chemical composition of a substance, while a chemical change does.
Fill in the blank: The substances present before a chemical change are called _____ and the substances formed are called _____ .
reactants, products
What is the primary characteristic of a reversible chemical reaction?
A reversible chemical reaction can proceed in both forward and reverse directions.
What does it mean for a reaction to reach equilibrium?
Equilibrium occurs when the rate of the forward reaction equals the rate of the reverse reaction, and concentrations remain constant.
