CHEM 1113- Ch. 4 Homework (Chemical Reactions & Aqueous Solutions)
- Zn - K
According to the activity series, which of these metals will react with most acids to produce H2 gas? - Zn - K - Pt
K3PO4(aq)+AlCl3(aq)⟶3KCl(aq)+AlPO4(s) This reaction in words would be: potassium phosphate+aluminum chloride ⟶ potassium chloride+aluminum phosphate The unbalanced chemical equation is: K3PO4(aq)+AlCl3(aq)⟶KCl(aq)+AlPO4(s) The balanced chemical equation is: K3PO4(aq)+AlCl3(aq)⟶3KCl(aq)+AlPO4(s)
Aqueous potassium phosphate reacts with aqueous aluminum chloride to form aqueous potassium chloride and solid aluminum phosphate. Write the balanced chemical equation for the reaction. Include physical states.
C3H8 + 5O2 = 3CO2 + 4H2O 3BaCl2 + 2K3PO4 --> Ba3(PO4)2 + 6KCl 2Cu(NO3)2 --> 2CuO + O2 + 4NO2 4Fe + 3O2 = 2Fe2O3
Balance the equations by adding coefficients as needed. (Do not add anything if the coefficient is 1)
2Sb + 3Cl2 ⟶ 2SbCl3 Mg3N2 + 6HCl ⟶ 3MgCl2 + 2NH3
Balance the equations by inserting coefficients as needed. Sb + Cl2 ⟶ SbCl3 Mg3N2 + HCl ⟶ MgCl2 + NH3
ACID = HI / H2SO3 / H2C2O4 BASE = Sr(OH)3 / LiOH SALT = BaF2 / KNO3 / NH4NO3
Classify the compounds as acids, bases, or salts. - HI - H2SO3 - LiOH - BaF2 - H2C2O4 - KNO3 - Sr(OH)3 - NH4NO3
molecular equation: Na2CO3 (aq) + NiCl2 (aq) ⟶ NiCO3 (s) + 2NaCl (aq) ionic equation: Ni2+(aq)+CO2−3(aq) ⟶ NiCO3(s)
Complete and balance the molecular equation for the reaction of aqueous sodium carbonate, Na2CO3, and aqueous nickel(II) chloride, NiCl2. Include physical states. Na2CO3 (aq) + NiCl2 (aq) ⟶ molecular equation: net ionic equation:
2K3PO4 (aq) + 3MgCl2 (aq) ⟶ Mg3(PO4)2 (s) + 6KCl (aq) AgNO3 (aq) + NaCl (aq) ⟶ AgCl (s) + NaNO3 (aq)
Complete and balance the precipitation reactions. Include physical states. Refer to the solubility rules as necessary. AgNO3 (aq) + NaCl (aq) ⟶ K3PO4 (aq) + MgCl2 (aq) ⟶
CdCl2(aq)⟶Cd2+(aq)+2Cl−(aq) Cadmium chloride contains two types of ions: Cd2+ and Cl−. When a formula unit of CdCl2 dissolves in water, the ions separate, or dissociate, forming one Cd2+ ion and two Cl− ions. CdCl2(aq)⟶Cd2+(aq)+2Cl−(aq) Because CdCl2 is soluble in water, a single arrow is typically used for the dissociation reaction. However, even CdCl2(aq) can become saturated, justifying the use of a double arrow in some situations.
Complete the equation for the dissociation of: CdCl2(aq) ⟶ (Omit water from the equation because it is understood to be present)
Na2SO4 Determine the relative numbers and charges of the ions of the ionic species dissolved in solution in the diagram. The solution contains eight cations with a +1 charge and four anions with a −2 charge. Then, determine the relative numbers and charges of the ions in each of the ionic compounds and compare them to the ionic species dissolved in solution in the diagram. The charge on a monatomic ion can be determined from its position on the periodic table. You can look up the charge of a polyatomic ion. Sodium is in group 1A and forms monatomic ions with a +1 charge, Na+. Sulfate is a polyatomic ion with a −2 charge, SO42−. The diagram shows twice as many cations as anions, which is consistent with the formula Na2SO4. The remaining compounds contain ions that do not have the correct charges or are present in an incorrect ratio.
Consider the diagram of an aqueous solution of a soluble ionic compound. Determine which ionic compound is dissolved in solution. a) KClO4 b) MgCl2 c) Ca(NO3)2 d) Na2SO4
The species that appear as both reactants and products are known as the spectator ions. In this reaction, Na+ (aq) and NO−3 (aq) are spectator ions.
Consider the equation. NaCl (aq) + AgNO3 (aq) ⟶ AgCl (s) + NaNO3 (aq) Identify the spectator ions in the equation.
Diagram A When CaCl2, a water soluble ionic compound, dissolves in water it splits into its component ions, Ca2+ and Cl−. The chemical formula shows that each formula unit of CaCl2 contains one Ca2+ and two Cl− ions. Therefore, there will be twice as many Cl− ions in solution as Ca2+ ions. The correct diagram contains three +2 particles and six −1 particles, which are the result of three formula units of CaCl2 dissolving in water.
Determine which diagram best represents the ionic compound CaCl2 dissolved in water.
Electrolytes are compounds that dissociate into their component ions and conduct electricity in aqueous solution. Electrolytes are classified by the extent to which they dissociate and how well they conduct electricity. Strong electrolytes dissociate completely when dissolved in solution and conduct electricity very well. When a strong electrolyte dissolves, all of the molecules will dissociate into ions. Weak electrolytes only partially dissociate when dissolved in solution and do not conduct electricity as well as strong electrolytes. When a weak electrolyte dissolves, some of the molecules will remain intact and some of the molecules will dissociate into ions. Non-electrolytes do not ionize when they dissolve in solution, so they cannot conduct electricity in aqueous solution. When a non-electrolyte dissolves, all of the molecules will remain intact and none will dissociate into ions.
Each image depicts what happens when different types of compounds are dissolved in aqueous solution. Classify each image as that of a strong electrolyte, weak electrolyte, or non-electrolyte.
HCN (aq) + OH- (aq) ⟶ H2O (l) + CN- (aq)
For the chemical reaction, HCN (aq) + KOH (aq) ⟶ H2O (l) + KCN (aq) Write the net ionic equation, including the phases.
H+ (aq) + OH− (aq) ⟶ H2O (l) Since Na+ and ClO−4 were canceled out, they are considered spectator ions.
For the chemical reaction: HClO4 (aq) + NaOH (aq) ⟶ H2O (l) + NaClO4 (aq) Write the net ionic equation, including the phases. Which ions are considered spectator ions for this reaction?
K: Reactants: +1 Products: +1 Cl: Reactants: +1 Products: -1 O: Reactants: -2 Products: 0 The oxidized element is oxygen. The reduced element is chlorine.
For the reaction KClO ⟶ KCl + 1/2O2 Assign oxidation numbers to each element on each side of the equation. Which element is oxidized? Which element is reduced?
The balanced chemical equation for the overall reaction of the hydrogen fuel cell is as follows: 2H2(g)+O2(g)→2H2O(l) The oxidizing agent is O2. The reducing agent is H2 . The electrons transferred in the balanced chemical equation are 4.
In a hydrogen fuel cell, hydrogen gas and oxygen gas are combined to form water. Write the balanced chemical equation describing this reaction using the lowest whole‑number coefficients. Identify the oxidizing agent. Identify the reducing agent. Determine the number of electrons transferred in the balanced chemical equation.
STRONG ACIDS = HNO3 & HI WEAK ACIDS = H3PO4 & HF STRONG BASES = KOH & Ba(OH)3 WEAK BASES = NH3 KOH and Ba(OH)2 are likely to be strong bases because they contain a metal cation and OH. Weak bases tend to contain nitrogen. Other than the nitrogen-containing compounds already identified as acids, the only remaining nitrogen‑containing compound is NH3, so you can presume it is a weak base.
In aqueous solution, classify these compounds as strong acids, weak acids, strong bases, or weak bases. - HI - KOH - NH3 - HF - HNO3 - H3PO4 - Ba(OH)3
- K2SO4 - AgNO3 - CuBr4
Predict whether the compounds are soluble or insoluble in water. - K2SO4 - AgNO3 - PbCl2 - BaSO4 - CuBr4 - FeCO3
BaI2
Suppose you are asked to determine the identity of a white solid. When you add water to the white solid, it dissolves and forms a clear solution. When you add a solution of Na2SO4, a white precipitate forms. Determine the identity of the original solid. - ZnI2 - AgI - MgI2 - BaI2
c) A+B⟶AB
The reaction between substance A (large, red spheres) and substance B (small, blue spheres) is shown in the diagram. Select the equation that best describes the reaction. a) 4A+4B⟶4AB b) A+B⟶4AB c) A+B⟶AB d) 4A+4B⟶AB
- NaCl = strong electrolyte - HCl = strong electrolyte - NH3 = weak electrolyte - NaOH = strong electrolyte - HC2H3O2 = weak electrolyte - C12H22O11 = non-electrolyte The amount of ionization affects the degree to which each aqueous solution conducts electric current, as indicated by the brightness of the light bulb in the interactive. An electrolyte solution has the ability to conduct electricity. A strong electrolyte fully ionizes, which results in the light bulb being brightly lit. A weak electrolyte partially ionizes, which means the solution does not conduct electricity as well as a strong electrolyte. The light bulb in a weak electrolyte solution is dimly lit. Notice that strong acids and bases are strong electrolytes, whereas weak acids and bases are weak electrolytes. A non-electrolyte does not ionize, which means the solution does not conduct electricity. The light bulb in a non-electrolyte solution remains dark.
Use the Conductivity interactive to identify each aqueous solution as a strong electrolyte, weak electrolyte, or non-electrolyte. - NaCl - HCl - NH3 - NaOH - HC2H3O2 - C12H22O11
When the mystery solution is added to the Pb(NO3)2 and Ba(NO3)2 solutions, a precipitate forms. A precipitate does not form when it is added to the Ni(NO3)2 solution. The K2SO4 solution is the only solution that produces all of the same results as the mystery solution, so it must be the identity of the mystery solution.
Use the solubility interactive to determine whether a precipitate forms or not when the mystery solution is added to each solution in the table. The mystery solution is: - K2CO3 - K2SO4 - K2S - KI - KOH
Mn = +3 O = -2 Cl = +7
What is the oxidation state of each element in Mn(ClO4)3?
- Cr (s) + AgClO3 (aq) - Cd (s) + CuNO3 (aq)
Which pairs of reactants will result in a chemical reaction? Refer to the activity series as needed. - Sn(s)+MgCl2(aq) - Cr(s)+AgClO3(aq) - Cd(s)+CuNO3(aq) - Pt(s)+CoBr2(aq)
C7H16 + 11O2 → 7CO2 + 8H2O
Write and balance the equation for the complete combustion of heptane, C7H16.
O2 + 2NO → 2NO2
Write the balanced chemical equation for the reaction shown.
2 HCl (aq) + Ba(OH)2 (aq) ⟶ BaCl2 (aq) + 2 H2O (l)
Write the balanced equation for the neutralization reaction between HCl and Ba(OH)2 in an aqueous solution. Phases are optional.
2HCl (aq) + Sr(OH)2 (aq) ⟶ 2H2O (l) + SrCl2 (aq) H+ (aq) + OH- (aq) ⟶ H2O (l)
Write the balanced molecular equation and net ionic equation for the neutralization reaction between hydrochloric acid and strontium hydroxide. Include the phase of each species.
