Lesson 2 Flashcards
(26 cards)
What is a balanced chemical equation?
A balanced chemical equation has the same number of each type of atom on both sides of the equation.
True or False: In a balanced equation, the mass of reactants must equal the mass of products.
True
What is the law that states mass is conserved in a chemical reaction?
The Law of Conservation of Mass
Fill in the blank: To balance a chemical equation, you can only change the ______ of the compounds.
coefficients
What does it mean to ‘balance’ a chemical equation?
It means ensuring that the number of atoms of each element is the same on both sides of the equation.
Which of the following is a step in balancing chemical equations? A) Change the subscripts B) Add coefficients C) Ignore the law of conservation
B) Add coefficients
True or False: You can change the subscripts of a compound to balance an equation.
False
What is the first step in balancing a chemical equation?
Write the unbalanced equation.
What is the coefficient in a chemical equation?
A number placed before a compound to indicate how many molecules are involved.
Fill in the blank: In the reaction 2H2 + O2 → 2H2O, the coefficient for H2 is ______.
2
What is the product of the reaction between hydrogen and oxygen?
Water (H2O)
True or False: Balancing chemical equations requires knowledge of the chemical formulas involved.
True
What do you call the substances that undergo change in a chemical reaction?
Reactants
What do you call the substances formed as a result of a chemical reaction?
Products
How many oxygen atoms are in the balanced equation 4Fe + 3O2 → 2Fe2O3?
6
Fill in the blank: In the equation C3H8 + O2 → CO2 + H2O, the coefficient for CO2 after balancing is ______.
3
What is the balanced equation for the combustion of propane (C3H8)?
C3H8 + 5O2 → 3CO2 + 4H2O
True or False: Coefficients can be fractions when balancing equations.
True
What is the importance of balancing chemical equations in chemistry?
It ensures that the law of conservation of mass is upheld.
What is the process of balancing the equation 2H2 + O2 → 2H2O called?
Balancing a chemical reaction
Fill in the blank: The equation 2Na + Cl2 → 2NaCl is ______ balanced.
already
What is one common mistake made while balancing equations?
Changing the subscripts instead of the coefficients.
What does it mean if a chemical equation is unbalanced?
The number of atoms of at least one element is different on each side.
True or False: The same coefficients can be used for multiple compounds in a balanced equation.
True
