Stoichiometry
If 4.0 moles of H2 react with excess O2, how many moles of H2O are produced?
reaction: 2H2+O2→2H2O
4.0 mol H2O
What are the spectator ions in the reaction shown:
Cr2(SO)4(aq)+3(NH4)2CO3 (aq) → Cr2(CO3)3(s)+3 (NH4)2SO4(aq)
NH4+(aq) and SO42-(aq)
What is Gay Lussac's law? Write the equation and explain what it means.
P1/V1=P2/V2
Name 3 cations or anions that are always soluble, with no common exceptions.
Na+, K+, Li+, NH4+, NO3-, C2H3O2- (CH3COO-)
Balance this simple combustion reaction of methane:
CH₄ + O₂ → CO₂ + H₂O
CH₄ + 2 O₂ → CO₂ + 2 H₂O
How many grams of NaCl are produced when 3.0 g of Na react with excess Cl2?
Reaction: 2Na + Cl2 →2NaCl
7.6 g NaCl
Write the balanced COMPLETE ionic equation for the reaction when silver acetate and magnesium chloride are mixed in aqueous solution. If no reaction occurs, simply write only NR. Be sure to include the proper phases for all species within the reaction.
2Ag⁺(aq) + 2C₂H₃O₂⁻(aq) + Mg²⁺(aq) + 2Cl⁻(aq) → 2AgCl(s) + 2C₂H₃O₂⁻(aq) + Mg²⁺(aq)
A sample of gas at 25°C has a volume of 2.50 L. If the temperature increases to 75°C at constant pressure, what is the new volume?
2.92 L
Chlorides are generally soluble except when paired with these three cations.
Ag⁺, Pb²⁺, and Hg₂²⁺
This type of reaction occurs when hydrochloric acid reacts with sodium hydroxide, producing water and a salt.
Acid/base reaction
How many liters of CO2 (at STP) are produced from 15.0 g of CaCO3?
Reaction: CaCO3→CaO+CO2
3.36 L CO2
Write the balanced NET ionic equation for the reaction when strontium chloride and sodium phosphate are mixed in aqueous solution
2 PO₄³⁻(aq) + 3 Sr²⁺(aq) → Sr₃(PO₄)₂(s)
A gas occupies 4.00 L at 1.20 atm and 30°C. What will its volume be at 0.900 atm and 60°C? (Moles constant.)
5.85 L
Sulfates are usually soluble, but they form insoluble precipitates when paired with these major cations. Name three of the common exceptions.
Ba²⁺, Sr²⁺, Ca²⁺, Pb²⁺, or Hg₂²
When aqueous solutions of potassium iodide and lead(II) nitrate are mixed, a bright yellow solid forms. Name the precipitate
lead(II) iodide (PbI₂)
If 8.0g of CH4 react with 40.0 g of O2, which is the limiting reactant?
Reaction: Ch4+2O2→CO2+2H2O
O2 is limiting.
This reaction occurs when aqueous solutions of aluminum sulfate and sodium hydroxide are mixed. Write the balanced net ionic equation for the formation of the precipitate.
Al³⁺(aq) + 3 OH⁻(aq) → Al(OH)₃(s)
A rigid 3.00 L container holds helium gas at 2.50 atm and 27°C. The container is heated until the pressure reaches 4.00 atm. What is the final temperature in °C?
207°C
is calcium sulfate (CaSO₄) soluble or insoluble in water?
insoluble
Identify the species oxidized and reduced in the reaction below:
2 Al(s) + 3 Cu²⁺(aq) → 2 Al³⁺(aq) + 3 Cu(s)
Oxidized: Al → Al³⁺
Reduced: Cu²⁺ → Cu
A student reacts 5.00 g of CaCO3 with excess hydrochloric acid. The reaction produces CO2 (g). The student collects 1.72 g of CO2. What is the percent yield?
Rxn: CaCO3+2HCl→CaCl2+H2O+CO2
78.2%
When aqueous solutions of barium nitrate and potassium carbonate are combined, a precipitate forms. Write the balanced complete ionic equation AND the balanced net ionic equation. You must identify all spectator ions.
Molecular equation:
Ba(NO₃)₂(aq) + K₂CO₃(aq) → BaCO₃(s) + 2 KNO₃(aq)
Complete ionic equation:
Ba²⁺(aq) + 2 NO₃⁻(aq) + 2 K⁺(aq) + CO₃²⁻(aq) → BaCO₃(s) + 2 K⁺(aq) + 2 NO₃⁻(aq)
Spectator ions: K⁺ and NO₃⁻
Net ionic equation:
Ba²⁺(aq) + CO₃²⁻(aq) → BaCO₃(s)
0.850 g of an unknown gas occupies 450 mL at 755 mmHg and 45°C. Determine the molar mass of the gas.
61.6 g/mol
Determine whether ammonium phosphate is soluble or insoluble in water
soluble
When heated, solid potassium chlorate (KClO₃) decomposes into a metal chloride and a gas. Write the balanced chemical equation for this decomposition reaction.
2 KClO₃(s) → 2 KCl(s) + 3 O₂(g)