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 fully dissociate and are therefore strong electrolytes?
LiOH || NaCl || NH3 || BaSO4
LiOH, NaCl
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 on energy?
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
A gas in a sealed container attached to a piston is in a water bath. After a chemical reaction occurs, the water bath has increased in temperature and the piston has moved out. Has the energy of the system increased or decreased?
Decreased.
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)
During a chemical reaction, 0.235 kJ of heat flows out of the system and 130 J of work is done on the system. What is the total change in energy of the system?
-105 J
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 (II) 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
How much work is done on a system where there is a net change of 6.4 kJ and 1125J of heat flows into the system?
5.3 kJ