Reaction Basics
What is the name of the starting substances in a chemical reaction?
Reactants
What type of reaction occurs when two or more substances combine to form one product?
Synthesis (combination)
Balance the equation: H2 + O2 --> H2O
2,1,2
Predict the product 2Mg + O2 --> __________
2MgO
Classify and balance the reaction: N2 + H2 --> NH3
Synthesis 1,3,2
In the equation 2H2 + O2 --> 2H2O,
which substance is the product?
Water
Classify this reaction
2KClO3 --> 2KCl + 3O2
Decomposition
Balance the equation: Na + Cl2 --> NaCl
2,1,2
Predict the products and balance: CaCO3 -->
CaCO3 --> CaO + CO2 (Ca + CO3)
Predict the products and balance the reaction: K + H2O
2K + 2H2O --> 2KOH + H2 This is single replacement
Why must a chemical equation be balanced according to the law of conservation of mass?
Matter is neither created nor destroyed, so each element must have the same number of atoms on both sides
Classify this reaction: Zn + 2HCl --> ZnCl2 + H2
Single-replacement reaction
Balance the equation: Fe + O2 --> Fe2O3
4,3,2
Zinc reacts with copper(II) sulfate. Predict the products and write a balanced equation.
Zn + CuSO4 --> ZnSO4 + Cu
Calcium hydroxide reacts with hydrochloric acid. Predict the products, write their correct formulas, balance the equation, and classify the reaction
Ca(OH)2 + 2HCl --> CaCl2 + 2H2O double replacement
A student changes H2O into H2O2 to balance an equation. Explain why this is incorrect.
Changing a subscript changes the identity and chemical composition of the substance. Only coefficients may be changed when balancing.
Aqueous silver nitrate reacts with aqueous sodium chloride to form silver chloride and sodium nitrate. What type of reaction occurs, and what evidence supports your answer?
Double-replacement reaction; the ions exchange partners, and insoluble silver chloride forms a precipitate.
Balance the equation: Al + HCl --> AlCl3 + H2
2,6,2,3
Aqueous barium chloride reacts with aqueous sodium sulfate. Predict the products, write their correct formulas, and balance the equation.
BaCl2 + Na2SO4 --> BaSO4 + 2NaCl
A student writes the following equation for the complete combustion of methane: CH4 + O2 --> CO2 + H2O. Identify the problem, correct the equation, and explain why the original equation is incorrect.
The original equation is unbalanced because it has two oxygen atoms on the left but three on the right.
in the equation __Ca(OH)2 + __H3PO4 --> __Ca3(PO4)2 + __H2O
How many oxygens are on each side of the balanced reaction
14 oxygen atoms
Balance the combustion equation: C₃H₈ + O2 --> CO2 + H2O
1,5,3,4
Balance the combustion equation C3H8 + O2
1,5,3,4
Aluminum reacts with oxygen gas to form aluminum oxide. Write the correct product formula and balance the complete equation.
4Al + 3O2 --> 2Al2O3
Solid iron(III) oxide reacts with carbon monoxide gas to produce solid iron and carbon dioxide gas. Write the correct formulas, predict all products, balance the equation, and identify the reaction pattern.
Fe2O3 + 3CO --> 2Fe + 3CO2 This is a redox reaction; it does not fit neatly into the five basic reaction patterns. (If you said one of the replacements, you get points)