8:1 Chemical Names and Formulas
Learning Target 1. List and describe three observations that suggest a chemical reaction has taken place.
1. Evolution of heat and light. 2. Production of a gas. 3. Formation of a precipitate.
Learning Targets
1. List and describe three observations that suggest a chemical reaction has taken place. 2. List and describe three requirements for a correctly written chemical equation. Give an example. 3. Write an example of a word equation and a formula equation for a chemical reaction. 4. Describe how to balance a chemical equation.
Which equation is NOT balanced?
A 2H2 + O2 → 2H2O B 4H2 + 2O2 → 4H2O C H2 + H2 + O2 → H2O + H2O D 2H2 + O2 → H2O
When the equation Fe3O4 + Al → Al2O3 + Fe is correctly balanced, what is the coefficient of Fe?
A 3 B 4 C 6 D 9
Which of the following is a formula equation for the formation of carbon dioxide from carbon and oxygen?
A Carbon plus oxygen yields carbon dioxide. B C + O2 →CO2 C CO2 →C + O2 D 2C + O → CO2
What is the balanced equation for the combustion of sulfur?
A S(s) + O2(g) → SO(g) B S(s) + O2(g) → SO2(g) C 2S(s) + 3O2(g) → SO3(s) D S(s) + 2O2(g) → SO42-(aq)
Which word equation represents the reaction that produces water from hydrogen and oxygen?
A Water is produced from hydrogen and oxygen. B Hydrogen plus oxygen yields water. C H2 + O2 → water. D Water can be separated into hydrogen and oxygen.
What is the small whole number that appears in front of a formula in a chemical equation?
A a subscript B a superscript C a ratio D a coefficient
After the first steps in writing an equation, the equation is balanced by
A adjusting subscripts to the formula(s). B adjusting coefficients to the smallest whole-number ratio. C changing the products formed. D making the number of reactants equal to the number of products.
Which observation does NOT indicate that a chemical reaction has occurred?
A formation of a precipitate B production of a gas C evolution of heat and light D change in total mass of substances
Knowledge about what products are produced in a chemical reaction is obtained by?
A inspecting the chemical equation. B balancing the chemical equation. C laboratory analysis. D writing a word equation.
After the correct formula for a reactant in an equation has been written, the
A subscripts are adjusted to balance the equation. B formula should not be changed. C same formula must appear as the product. D symbols in the formula must not appear on the product side of the equation.
Learning Target 4. Describe how to balance a chemical equation.
MgO + SO₃ --> MgSO₄
Learning Target 3. Write an example of a word equation and a formula equation for a chemical reaction.
coefficients are used to satisfy the law of conservation of mass
Learning Target 2. List and describe three requirements for a correctly written chemical equation. Give an example.
1. The equation must represent known facts. 2. The equation must contain the correct formulas for the reactants and products. 3. The law of conservation of mass must be satisfied.