Limiting reagents + yield
Which reactant can be assumed to be completely consumed in a chemical reaction?
Write the net ionic equation for the reaction when aqueous solutions of barium nitrate and ammonium phosphate are mixed:
3Ba2+(aq) + 2PO4-3(aq) → Ba3(PO4)2 (s)
Which of the following are strong electrolytes?
LiOH || H2CO3 || NaCl || NH3 || HClO4
LiOH, NaCl, HClO4
Determine the oxidation number of each element in the ion Zn(OH)42-
Zn: +2 O: -2 H: +1
If heat is being released by a system, what is the sign on q?
Negative
When a question gives the amount of a product that is formed in a chemical reaction, is this the theoretical or actual yield?
The actual yield
Write the net ionic equation for the reaction when aqueous solutions of hydrochloric acid and sodium hydroxide are mixed:
H+(aq) + OH-(aq) → H2O(l)
When 1.00 mole of Na2SO4 is dissolved in water to make one liter of solution, what is the molarity of sodium ions in solution?
2 M
Determine the oxidation number of each element in the compound (NH4)2Cr2O7
N: -3 H: +1 Cr: +6 O: -2
What is a process that absorbs heat energy called, and what is the sign?
Endothermic, positive
Ethanol (CH3CH2OH) is converted into acetaldehyde (CH3CHO) using excess oxygen gas in the liver upon consumption of an alcoholic beverage. If Romeo consumes 100 g of ethanol, and 90.5 g of acetaldehyde is produced, what is the percentage yield?
CH3CH2OH + 1/2O2 → CH3CHO + H2O
95% yield
Write the net ionic equation for the reaction when aqueous solutions of ammonium phosphate and sodium sulfate are mixed:
No net ionic reaction occurs
Which of the following 0.1 M solutions has the highest concentration of ions?
HF || H2SO4 || C6H12O11 || Al2(SO4)3 || NaOH
Al2(SO4)3
Determine which element is reduced and which is oxidized in the following reaction:
MnO2 (s) + 4HCl(aq.) → MnCl2 (aq.) + Cl2 (g) + 2H2O(l)
Oxidized: Cl || Reduced: Mn
Determine the final temperature of a 376 g sample of gold that has an initial temperature of 398.0 K and loses 4.850 kJ of heat when placed in snow. The specific heat capacity of gold is 0.128 J/g*K.
297 K
If 22.3 g of ammonia is reacted with 16.5 g of oxygen gas to form nitric oxide and water, which is the limiting reagent?
4NH3 + 5O2 → 4NO + 6H2O
Oxygen gas is limiting
Write the net ionic equation for the reaction when aqueous solutions of sulfuric acid and barium hydroxide are mixed:
2H+(aq) + SO42-(aq) + Ba2+(aq) + 2OH-(aq) → 2H2O(l) + BaSO4 (s)
If 97.0 mL of a 1.30 M solution of LiCl is diluted to 1.50 L, determine the concentration of the new solution.
0.0841 M
Determine which species are the reducing and oxidizing agents in the following reaction:
3PbO(s) + 2NH3 (g) → N2 (g) + 3H2O(l) + 3Pb(s)
Oxidizing agent: PbO (lead II oxide) || Reducing agent: NH3 (ammonia)
A volume of 100 mL of 1M HCl at 298 K is added to 100 mL of 1M NaOH, also at 298 K. The final temperature is 300K. Calculate the enthalpy change in kJ/mol for the reaction.
16.7 kJ/mol
If 30.0 g of magnesium hydroxide react with 15.0 g of hydrochloric acid, what mass of water will be produced?
Mg(OH)2 + 2HCl → MgCl2 + 2H2O
7.41 g H2O
Write the net ionic equation for the reaction when aqueous solutions of lead nitrite and silver fluoride are mixed:
2Ag+(aq) + 2F-(aq) + Pb2+(aq) + 2NO2-(aq) → PbF2 (s) + 2AgNO2 (s)
What volume of 4.0 M potassium iodide solution is required to react with lead (II) nitrate to yield 89 g of lead (II) iodide?
97 mL
In which of the following compounds does sulfur have the lowest oxidation state?
Na2SO4 || H2S || S8 || S2Cl2 || NaSO3
H2S
A volume of 50.0 mL of 0.400 M HBr at 24.35 C is added to 50.0 mL of 0.400 M NaOH also at 24.35 C. The final temperature is 27.06 C. Calculate the enthalpy change in kJ/mol for the reaction.
56.7 kJ/mol