Question : 81.              When aqueous solutions of K2CO3 and CaCl2 mixed, what : 1335432

81.              When aqueous solutions of K2CO3 and CaCl2 are mixed, what is the correct formula for the precipitate that forms?

A)  KCl(s)    B)  K2Cl2(s)    C)  CaCO3(s)    D)  K2Ca(s)    E)  ClCO3(s)

82.              When aqueous solutions of NaOH and MgCl2 are mixed, a precipitate forms.  What is the correct formula for the precipitate?

A)  NaCl(s)    B)  NaCl2(s)    C)  MgCl2(s)    D)  MgOH(s)    E)  Mg(OH)2(s)

83.              Complete and balance the equation for the reaction that occurs when HCl(aq) and Mg(OH)2(aq) are mixed.  This reaction occurs in your stomach if you take Milk of Magnesia®.

A)HCl(aq) + Mg(OH)2(aq) ? MgCl2(aq) + H2O(l)

B)2HCl(aq) + Mg(OH)2(aq) ? MgCl2(aq) + H2O(l)

C)2HCl(aq) + Mg(OH)2(aq) ? MgCl2(aq) + 2H2O(l)

D)HCl(aq) + Mg(OH)2(aq) ? MgCl(aq) + H2O(l)

E)2HCl(aq) + Mg(OH)2(aq) ? MgCl2(aq) + H2(g)

84.              Complete and balance the equation for the reaction that occurs when H2SO4(aq) and NaOH(aq) are mixed.

A)H2SO4(aq) + NaOH(aq) ? NaSO4(aq) + H2(g)

B)H2SO4(aq) + NaOH(aq) ? NaSO4(aq) + H2O(l)

C)H2SO4(aq) + 2NaOH(aq) ? Na2SO4(aq) + H2O(l)

D)H2SO4(aq) + 2NaOH(aq) ? Na2SO4(aq) + 2H2O(l)

E)2H2SO4(aq) + 2NaOH(aq) ? Na2SO4(aq) + 2H2O(l)

85.              Complete and balance the equation for the reaction that occurs when HBr(aq) and KOH(aq) are mixed.

A)HBr(aq) + KOH(aq) ? KBr(aq) + H2O(l)

B)2HBr(aq) + KOH(aq) ? Br2(l) + H2O(l)

C)2HBr(aq) + KOH(aq) ? KBr(aq) + H2O(l)

D)HBr(aq) + KOH(aq) ? BrOH(aq) + KH(aq)

E)HBr(aq) + KOH(aq) ? KBrO(aq) + H2(g)

86.              When powdered sulfur burns in air, a purple flame is produced, as well as a toxic, foul-smelling gas.  Write a balanced equation for the reaction between sulfur and oxygen gas.

A)S8(s) + O2(g) ?  SO2(g)C)S8(s) + 8O2(g) ?  8SO2(g)

B)S8(s) + 4O2(g) ?  8SO2(g)D)2S8(s) + 8O2(g) ?  8SO2(g)

87.              When acetylene gas, C2H2, burns in air, a combustion reaction occurs.  Write a balanced equation to represent this reaction, which occurs when welding torches are used.

A)C2H2(g) + O2(g) ?  C2H2O2(g)

B)C2H2(g) + O2(g) ?  C2O2(g) + H2(g)

C)C2H2(g) + O2(g) ?  CO2(g) + H2O(g)

D)C2H2(g) + O2(g) ?  2CO2(g) + H2O(g)

E)2C2H2(g) + 5O2(g) ?  4CO2(g) + 2H2O(g)

88.              Sterno, or “canned heat,” contains methanol, CH3OH, and is used for heating containers of food.  Write a balanced equation to represent the combustion reaction that occurs when methanol burns in air.

A)CH3OH(l) + O2(g) ?  CH4O3(g)

B)2CH3OH(l) + O2(g) ?  C2O2(g) + H2(g)

C)CH3OH(l) + O2(g) ?  CO2(g) + H2O(g)

D)2CH3OH(l) + 3O2(g) ?  2CO2(g) + 4H2O(g)

E)2CH3OH(l) + 6O2(g) ?  2CO2(g) + 4H2O(g)

89.              Would an aqueous solution of CH3OH contain ions?  If so, indicate the formulas of the ions in the solution.

A)No, this substance would not form ions in solution.

B)Yes.  CH3+(aq) + OH?(aq)

C)Yes.  CH3?(aq) + OH+(aq)

D)Yes.  CH4+(aq) + O?(aq)

E)Yes.  CH42+(aq) + O2?(aq)

90.              Would an aqueous solution of K2SO4 contain ions?  If so, indicate the formulas of the ions in the solution.

A)No, this substance would not form ions in solution.

B)Yes.  K2+(aq) + SO4?(aq)

C)Yes.  K22+(aq) + SO42?(aq)

D)Yes.  2K+(aq) + SO42?(aq)

E)Yes.  2K+(aq) + S2?(aq) + 4O2?(aq)