Chemical reactions Flashcards
(26 cards)
What is a chemical reaction?
A process where substances (reactants) are transformed into new substances (products).
True or False: In a chemical reaction, mass is created or destroyed.
False: Mass is conserved in a chemical reaction.
What are the main signs that a chemical reaction has occurred?
Color change, gas production, temperature change, and formation of a precipitate.
Fill in the blank: In a chemical equation, the substances on the left side are called __________.
reactants
What are products in a chemical reaction?
The new substances formed as a result of the reaction.
What is the law of conservation of mass?
Matter cannot be created or destroyed in a chemical reaction.
What is a reactant?
A substance that participates in a chemical reaction.
Which of the following is a type of chemical reaction: A) Synthesis B) Digestion C) Evaporation?
A) Synthesis
What is an exothermic reaction?
A reaction that releases energy, usually in the form of heat.
What is an endothermic reaction?
A reaction that absorbs energy from its surroundings.
True or False: All chemical reactions require heat to occur.
False: Some reactions can occur at room temperature.
What is a catalyst?
A substance that speeds up a chemical reaction without being consumed.
Fill in the blank: __________ reactions involve the breaking down of a compound into simpler substances.
Decomposition
What is a combustion reaction?
A reaction that occurs when a substance combines with oxygen, releasing energy.
What is the role of an indicator in a chemical reaction?
To show a change in pH or the presence of a specific substance.
What is a balanced chemical equation?
An equation where the number of atoms for each element is the same on both sides.
Which of the following is a physical change: A) Melting ice B) Rusting of iron?
A) Melting ice
What happens to the bonds in reactants during a chemical reaction?
The bonds are broken and new bonds are formed to create products.
What type of reaction occurs when an acid reacts with a base?
Neutralization reaction.
Fill in the blank: __________ is the process of mixing two or more substances to form a new product.
Reaction
What is a precipitate?
A solid that forms and settles out of a liquid mixture during a chemical reaction.
True or False: Chemical reactions can be reversed.
True: Some reactions can be reversed, known as reversible reactions.
What is the purpose of a chemical formula?
To represent the composition of a substance using symbols and numbers.
What is a single displacement reaction?
A reaction where one element replaces another in a compound.
