FLVS Chemistry Honors Module Four
What is the oxidation number of nitrogen in the nitrate ion NO31−?
+5
Match each subscript symbol to its correct meaning. (g)(l)(aq)
1) Gas 2) Liquid 3) Aqueous solution
Fill in the blank with the correct number to balance the equation: 4Cr + 3O2 → ___Cr2O3. (Enter only a whole number.)
2
Which of the following shows an accurate combustion reaction?
2CH4 + O2 → 2CH3OH
Which chemical equation correctly represents the reaction that takes place when nitrogen gas and hydrogen gas are formed as ammonia decomposes?
2NH3(g) → N2(g) + 3H2(g)
A chemical equation is shown: Al + O2 → Al2O3 According to the law of conservation of mass, how many atoms of oxygen exist in the products of this reaction?
6
Zinc metal reacts with hydrochloric acid (HCl) to produce hydrogen gas. What best describes this reaction?
A single replacement reaction takes place because zinc is more reactive than hydrogen.
Which of the following is a double replacement reaction?
Ca(OH)2 + H2SO4 → CaSO4 + 2H2O
Why is the reaction between potassium (K) and chlorine (Cl) considered an oxidation-reduction reaction?K(s) + Cl2(g) → 2KCl(s)
Chlorine takes electrons from potassium in the reaction.
What substance is reduced in the reaction 2Fe2+ + Cl2 → 2Fe3+ + 2Cl−?
Cl2, because it gained electrons
Cu + O2 → CuO2 Mg + H2O → MgO + H2 SO + H2O → SO2 + H2
Cu + O2 → CuO2
A decomposition reaction always breaks a compound down into two pure elements.
False
A double replacement reaction is a reaction in which one element replaces a similar element within a compound.
False
All redox reactions are combustion reactions.
False
When CaCl2 and Zn react together, zinc (Zn) can replace chlorine (Cl) in the compound because zinc is higher on the periodic table.
False
The table shows the nature of the reactants and products formed in a certain type of chemical reaction. Reactants: Ionic compound + Ionic compound Products: Ionic compound + Ionic compound Which of the following is true about this type of chemical reaction?
It is a double replacement reaction, and all four compounds are different.
For the reaction Na + H2O → NaOH + H2, what are the reactants, products, and correct coefficients in the balanced equation?
Reactants: 2Na and 2H2O; products: 2NaOH and 1H2
Which of the following laboratory procedures best illustrates the law of conservation of mass? (Assume the product of the reaction includes the mass of any unused reactants.)
Reacting 12 g of C with 32 g of O2 to form 44 g of CO2
Which of the following is a synthesis reaction?
SO3 + H2O → H2SO4
What is true of a decomposition reaction?
The addition of energy in the form of heat or electricity is often required.
When methane, CH4, is combusted, it produces carbon dioxide, CO2, according to the unbalanced equation: CH4 + O2 → CO2 + H2O. Write the balanced equation for this reaction, and explain how it is possible for 10 grams of methane fuel to burn and emit 27 grams of carbon dioxide. Discuss whether or not this reaction obeys the law of conservation of mass.
The balanced equation is CH4(g)+2O2(g)→CO2(g)+2H2O(g) In the burning reaction, methane (CH₄) reacts with oxygen (O₂) to produce carbon dioxide (CO₂) and water (H₂O): CH₄ + 2 O₂ → CO₂ + 2 H₂O This reaction obeys the law of conservation of mass because nothing was created or destroyed just rearranged.
Read the following chemical equation: Ti + 2Cl2 → TiCl4 Which statement best identifies and describes the reducing agent in the reaction?
Ti is the reducing agent because it changes from 0 to +4 oxidation state.
The reaction CO2(g) → C(s) + O2(g) is a decomposition reaction.
True
An unbalanced chemical equation is shown: H2O2 → 2H2O + O2 Which of the following statements explains why the equation is not balanced?
Two H2O2 molecules should decompose to form the given products.
Which of the following reactions could be used to power a battery because of the transfer of electrons? Pb22+ + 2Br− → PbBr CaCl2 + 2NaOH → Ca(OH)2 + 2NaCl KOH + HCl → KCl + H2O Zn + Cu2+ → Zn2+ + Cu
Zn + Cu2+ → Zn2+ + Cu
