Test 3 Chem 115 Study Guide

The oxidation number of O in compounds is usually ___, but its ___ in peroxides (O2)

-2, -1

What is the molar concentration of sodium ions in a 0.350 M Na₃PO₄ solution?

1.05 M .350 M * (3/1) = 1.05 M

What is the value of the gas constant, R, in units of mmHg * cm^3/mol*K

6.236 x 10^4

What is the oxidation number of the sulfur atom in H2SO4? A) -2 B) +6 C) +4 D) +2

B) +6

What is the oxidation number of the oxygen atom in H2O2? A) +1 B) -1 C) -2 D) +2

B) -1 Oxygen is usually -2, but since theres 2 of them, its -1 in this case.

Based on the balanced chemical equation shown below, what volume of .250 M K2S2)3(aq) is needed to completely react with 12.44 mL of 0.125 M KI3(aq)? A) 49.8 mL B) 12.4 mL C) 6.22 mL D) 3.11 mL

B) 12.4 mL

Which of the following compounds is not an Arrhenius acid? A) CH3CO2H B) CH3NH2 C) H2SO4 D) HNO3

B) CH3NH2

Which species functions as the oxidizing agent in the following reduction-oxidation reaction: Zn(s) + Cu2+(aq) -> Cu(s) + Zn2+(aq) A) Zn2+(aq) B) Cu2+ (aq) C) Cu(s) D) Zn(s)

B) Cu2+ (aq)

What is the oxidation number change for the iron atom in the reaction: 2 Fe2O3(s) + 3 C(s) -> 4 Fe(s) + 3 CO2(g) A) +6 B) -6 C) -3 D) +3

C) -3

In the unbalanced equation shown below how many electrons are needed in the balanced oxidation half reaction? C2O42- (aq) + MnO4-(aq) -> CO2(aq) + Mn2+(aq) A) 2 B) 5 C) 10 D) 1

C) 10

Determine the number of water molecules necessary to balance the reduction half reaction of: _MnO4-(aq) -> _MnO2(s) that occurs in a basic solution A) 4 B) 3 C) 2 D) 5

C) 2

What are the coefficients in front of Fe(s) and O3(g) when the following redox equation is balanced in an acidic solution: __Fe(s) + __O3(g) --> __Fe2O3(s) + __O2(g) A) 3,2 B) 2,2 C) 2,3 D) 3,4

C) 2,3

Determine the number of water molecules necessary to balance the reduction half reaction of: _MnO4-(aq) - > _Mn2+(aq) that occurs in an acidic solution A) 7 B) 5 C) 4 D) 2

C) 4

Determine the number of water molecules necessary to balance the following chemical equation: _Cr2O72-(aq) + _Cl-(aq) + _H+(aq) -> _Cr3+(aq) + _Cl2(g) + _H20 A) 5 B) 14 C) 7 D) 3

C) 7

A A 0.286 g sample of gas occupies 125 ml at 60 cm of Hg at 25C what is the molar mass of the gas? A) 5.9 g/mol B) 59 g?mol C) 71 g/mol D) 44 g/mol

C) 71 g/mol n=PV/RT n=(60*125)/

In which compound is the oxidation state oxygen not -2? A) Al2O3 B) Li2O C) Na2O2 D) MgO

C) Na2O2

What is the oxidation half reaction in the chemical reaction Zn(s) + 2 H+(aq) --> Zn2+(aq) + H2(g) A) Zn2+(aq) + 2e- -> Zn(s) B) H2(g) -> 2 H+(aq) + 2e- C) Zn(s) -> Zn2+(aq) + 2e- D) 2 H+(aq) + 2e- -> H2(g)

C) Zn(s) -> Zn2+(aq) + 2e-

H₂O (water), CH₃OH (methane alcohol), CH₃CH₂OH (ethyl alcohol), HOCH₂CH₂OH (ethylene glycol), C₁₂H₂₂O₁₁ (sucrose) are all

non electrotyles

Hbr, HCl, HClO4, KBr, NaCl are all classified as

strong electrolytes

CH₂CO₂H (Acetic acid), HCO₂H (formic acid), HF (hydriofluoric acid), NH₃ (aqueous ammonia), and CH₃NH₂ (aqueous methylamine) are all

weak electrolytes

single-replacement reaction

where an element reacts with a compound and takes the place of another element in that compound.

double replacement reaction

where two compounds react, and the positive ions (cation) and the negative ions (anion) of the two reactants switch places, forming two new compounds or products.

Formula when given pressure and temperature.

(P1/T1) = (P2/T2) if kelvin/atm ( (P1/760) / (T1+273.15)) = ( (P2/760) / (T2+273.15))

Formula when given volume and temperature

(Ti/Vi) = (Tf/Vf) add 273.15 to the temperatures, leave the volume in mL/L.

The oxidation number of a group 17 element (middle section) in a binary compound

-1

A 75L steel tank at 20C contains C2H2, at a pressure of 1.39 atm. How many grams of acetylene are in the tank? A) 113g B) 4.33g C) 6.01g D) 1650g

A) 113g PV = nRT PV/RT = n (1.39)(75)/(0.082)(293.15)=n n=4.33 4.33 X C2H2 mass = 113g

Predict the products of a reaction between AgNO3(aq) and KBr(aq) A) AgBr(s) and KNO3(aq) B) Ag(s) and Br2(I) C) AgNO3(aq) and KBr(aq) D) Ag(s) and NO(g)

A) AgBr(s) and KNO3(aq)

What are the coefficients in front of NO3- (aq) and Cu(s) when the following redox equation is balanced in an acidic solution: __NO3-(aq) + __Cu(s) --> __NO(g) + __Cu2+(aq) A) 2,6 B) 3,4 C) 3,6 D) 2,3

D) 2,3

How many molecules of N2 are in a 500.0 mL container at 780 mm Hg and 135 C. A) 2.79 x 10^22 B) 8.76 x 10^21 C) 2.65 x 10^22 D) 9.23 x 10^21

D) 9.23 x 10^21

What is the celsius temperature of 100 g of chlorine gas in a 40 L container at 800 mm Hg. A) 182 C B) 364 C C) -91 C D) 91 C

D) 91 C PV = nRT PV/nR = T (800/760atm)*(40L)/(100g*1/71)(0.082) = T T = 364.5-273.15 = 91 C

Which one of the following compounds behaves as an acid when dissolved in water? A) CH4 B) KOH C) BaO D) HBr

D) HBr

When dissolved in water, of HClO4, Ca(OH)2, KOH, HI, which are acids? A) only KOH B) Ca(OH)2 and KOH C) only HI D) HClO4 and HI

D) HClO4 and HI

Which of the following is not a strong acid? A) HBr B) HCl C) HI D) HF

D) HF

Which pair of reactants will produce a precipitate when mixed together? A) HCl(aq) and Na2S(aq) B) HCl(aq) and NaOh(aq) C) HCl(aq) and Na2CO3(aq) D) Hcl(aq) and Pb(NO3)2 (aq)

D) Hcl(aq) and Pb(NO3)2 (aq)

Which species functions as the reducing agent in the following reduction-oxidation reaction: 2 P(s) + 3 Br2(L) --> 2 PBr3(L) A) P3+ (aq) B) Br- (aq) C) Br2 (L) D) P(s)

D) P(s)

What is the oxidation number of the sulfur atom in S8? A) +6 B) +8 C) -2 D) 0

Its 0 because a free element will always have an oxidation number of 0.

Mixing which pair of reactants will result in a precipitation reaction? A) NaNO3(aq) + NH4Cl (aq) B) K2SO4(aq) + Ba(NO3)2(aq) C) HCl(aq) + Ca(OH)2(aq) D) Csl(aq) + NaOH(aq)

K2SO4(aq) + Ba(NO3)2(aq)

Which pair of compounds is soluble in water? A) CdS and (NH4)2S B) AgBr and AgI C) NaNO3 and CuCO3 D) KI and Ba(NO3)2

KI and Ba(NO3)2

What ion is provided when Arrhenius bases dissolve in water? A) Na+ B) H+ C) Cl- D) OH-

OH-

Which one is soluble in water? A) ZnCO3 B) Ag3PO4 C) Pb(NO3)2 D) CuS

Pb(NO3)2

a balanced net ionic equation for the reaction of Pb(NO3)2 (aq) with NaI(aq)

Pb2+(aq) + 2 I-(aq) ----> PbI2

When K2SO4(aq) AND Pb(NO3)2(aq) are mixed, a white colored precipitate forms which is A) Pb B) KNO3 C) K2SO3 D) PbSO4

PbSO4

Which one of the following compounds is insoluble in water? A) K2SO4 B) PbSO4 C) NaNO3 D) Rb2CO3

PbSO4

Oxidation Reduction Reaction

This is when a transfer of electrons occurs

Precipitation Reaction

Two solutions are mixed to form a insoluble solid (precipitate) is formed

Acid Base Neutralization Reaction

When an acid and a base combine to produce a salt and water.

What equation is used to find molar concentration?

When your given (xxx M), you look at how many (#) the determined element has. Multiply that by (xxx M) Ex: .350 M * (3/1) = 1.05 M