Holt Ch 8 PPT

Open Ended

Translate the following chemical equation into a sentence: BaCl2(aq) + Na2CrO4(aq) → BaCrO4(s) + 2NaCl(aq)

Multiple Select

Which of the following are indications that a chemical reaction has occurred?

• Evolution of energy as heat and light

• Production of a gas

• Formation of a precipitate

• Change in temperature

Multiple Select

Which of the following are steps in balancing a chemical equation?

• Count the number of atoms of each element on both sides of the equation.

• Adjust the coefficients to get the same number of each type of atom on both sides.

• Change the subscripts in the chemical formulas to balance the atoms.

• Check to make sure the equation obeys the law of conservation of mass.

Open Ended

How would you explain the significance of being able to communicate chemical reactions using equations to someone unfamiliar with chemistry?

Multiple Choice

Why is it important for scientists to use chemical equations when describing chemical reactions?

• Because chemical equations are universally understood and concise

• Because chemical equations are written in full sentences

• Because chemical equations are only used in textbooks

• Because chemical equations are not important in science

Open Ended

Explain the difference between reactants and products in a chemical reaction.

Multiple Choice

According to the law of conservation of mass, what must be true for any given chemical reaction?

• The total mass of reactants must equal the total mass of products.

• The total mass of reactants must be less than the total mass of products.

• The total mass of reactants must be greater than the total mass of products.

• The total mass of reactants is not related to the total mass of products.

Fill in the Blank

Fill in the blank: In a chemical equation, a ___ is a small whole number that appears in front of a formula.

Multiple Choice

What does the following chemical equation represent: (NH4)2Cr2O7(s) → N2(g) + Cr2O3(s) + 4H2O(g)?

• The decomposition of ammonium dichromate into nitrogen, chromium(III) oxide, and water.

• The combination of nitrogen and water to form ammonium dichromate.

• The reaction of chromium(III) oxide with nitrogen to form water.

• The formation of ammonium dichromate from its elements.

Fill in the Blank

Fill in the blank: In a word equation, the reactants and products in a chemical reaction are represented by ___.

Multiple Choice

What is the main difference between a word equation and a formula equation in chemistry?

• A word equation uses words to represent reactants and products, while a formula equation uses chemical symbols and formulas.

• A word equation is always balanced, while a formula equation is not.

• A formula equation uses only numbers, while a word equation uses only letters.

• A word equation is used only for reversible reactions, while a formula equation is not.

Multiple Choice

What is produced when aqueous solutions of barium chloride and sodium chromate react?

• A precipitate of barium chromate and sodium chloride in aqueous solution

• A precipitate of sodium chloride and barium chromate in aqueous solution

• A precipitate of barium chloride and sodium chromate in aqueous solution

• A precipitate of sodium chromate and barium chloride in aqueous solution

Multiple Choice

Which symbol in a chemical equation indicates that a reactant is heated?

• Δ or heat

• ↑

• 2 atm

• MnO₂

Fill in the Blank

The ratio of H2 to Cl2 to HCl in the reaction H2(g) + Cl2(g) → 2HCl(g) is 1:1:___.

Multiple Select

Which of the following symbols are used to indicate the physical state of reactants or products in a chemical equation?

• (s)

• (l)

• (g)

• (aq)

Multiple Choice

What do the coefficients in a chemical equation indicate?

• Relative amounts of reactants and products

• Absolute amounts of reactants and products

• The speed of the reaction

• The color of the products

Open Ended

Why is it important to use the correct symbols and coefficients when writing chemical equations?

Open Ended

Explain the importance of balancing chemical equations, using the combustion of methane as an example.

Multiple Choice

What does the symbol (aq) represent in a chemical equation?

• A reactant or product in the gaseous state

• A reactant or product in the aqueous solution (dissolved in water)

• A reactant or product in the solid state

• A reactant or product in the liquid state

Multiple Select

Which of the following can be determined from the coefficients of a chemical reaction?

• Relative masses of reactants and products

• Absolute masses of reactants and products

• The number of moles involved

• The color of the reactants

Multiple Choice

Which statement about chemical equations is correct?

• They give no information about the speed of the reaction.

• They show how atoms bond during the reaction.

• They indicate whether a reaction will occur.

• They provide absolute amounts of reactants.

Open Ended

Describe the steps involved in writing and balancing a chemical equation, using the reaction between sodium oxide and water as an example.

Multiple Choice

What is the balanced chemical equation for the reaction between sodium oxide and water?

• Na2O(s) + H2O(l) → 2NaOH(aq)

• Na2O + H2O → NaOH

• NaO + H2O → NaOH(aq)

• Na2O(s) + H2O(l) → NaOH(aq)

Multiple Choice

What topic from Chapter 8 would you like to learn more about or found most interesting?

• Indications of a Chemical Reaction

• Characteristics of Chemical Equations

• Significance of a Chemical Equation

• Balancing Chemical Equations

Open Ended

How would you explain the importance of chemical equations in communicating scientific information to others?