UNIT 4 TEST RETAKE

100mL of 0.500 M HCl is used to titrate a 50mL solution of NaOH. What is the concentration of NaOH?

1 M

64g of HI (molar mass of 128 g/mol) is dissolved into 0.500L of water. What is the molarity of the solution?

1 M

Mass of NaINaI crystals2.0g Color of NaINaI crystalsWhite Color of solid recoveredYellow Color of filtered solutionColorless Mass of dry solid recovered3.0g When students added 2.0g of NaI crystals to 100.mL of Pb(NO3)2(aq), a yellow precipitate formed. After the solution was filtered, the yellow solid was dried and weighed. Data from the experiment are shown in the table above. Which of the following claims is best supported by the observations?

A chemical change occurred when a yellow, insoluble compound with a larger mass than the original NaI formed.

C6H5COOH(aq) + NaOH(aq) → C6H5COONa(aq) + H2O(l) Which of the following identifies a conjugate acid-base pair in the reaction represented above?

ACID- C6H5COOH CONJUGATE BASE-C6H5COO

Na2CO3(aq) + 2 HCl(aq) → 2 NaCl(aq) + H2O(l) + CO2(g) A student combined two colorless aqueous solutions. One of the solutions contained Na2CO3 as the solute and the other contained HCl. The chemical reaction that took place is represented by the equation above. What experimental result would be evidence that a chemical reaction took place when the solutions were combined?

Bubbles formed when the two solutions were combined.

CuCl2(aq) + NaOH(aq) → Cu(OH)2(s) + NaCl(aq) Which of the equations below is the balanced net ionic equation

Cu2+(aq) + 2 OH-(aq) → Cu(OH)2(s)

HCl(aq) + H2O(l) → H3O+(aq) + Cl−(aq) For the dissolution of HCl in water represented above, which of the following pairs includes the Brønsted-Lowry bases?

H2O(l) and Cl−(aq)

Which of the following best describes the process represented above that takes place when NH3 is added to water?

It is an acid-base reaction in which a proton is exchanged from H2O to NH3.

Zn(s) + 2HCl(aq) → ZnCl2(aq) + H2(g) When the reaction represented above proceeds, heat is produced. Which of the following best describes the reaction?

It is an oxidation-reduction reaction because zinc is oxidized and hydrogen is reduced.

2 Mg(s) + SiCl4(l) → 2 MgCl2(s) + Si(s) Which of the following statements about the reaction represented above is correct?

It is an oxidation-reduction reaction, and Mg is oxidized.

A chemistry teacher carried out several demonstrations, and students recorded their observations. For one of the demonstrations, a student concluded that a physical change took place, but not a chemical change. Which of the following observations could the student have made of the results of the demonstration?

One piece of solid substance was changed into small pieces.

I2(aq) + C6H8O6(aq) → C6H6O6(aq) + 2I−(aq) + 2H+(aq) The compound C6H8O6 reacts with I2 according to the reaction represented by the equation above. The reaction is correctly classified as which of the following types?

Oxidation-reduction, because I2 is reduced.

K2SO3(aq) + 2HNO3(aq) → 2 KNO3(aq) + SO2(g) + H2O(l) According to the balanced chemical equation above, when 100.0mL of 0.100 M K2SO3(aq) is mixed with 100.0mL of 0.200 M HNO3(aq) at 30°C and 1 atm, the volume of SO2 gas produced is 0.24 L. If it is assumed that the reaction goes to completion, which of the the following changes would double the volume of SO2 produced at the same temperature and pressure? (For each change, assume that the other solutions and volumes remain the same.)

Using 200.0mL of 0.100 M K2SO3(aq) and 200.0mL of 0.200 M HNO3(aq), because these are the required stoichiometric amounts

In the reaction between C5H5N(aq) and HCl(aq) represented above, C5H5N acts as

a Brønsted-Lowry base

Al(s) → Al3+(aq) + 3e− Sn2+(aq) + 2e− → Sn(s) Based on the half-reactions represented above, which of the following is the balanced ionic equation for the oxidation-reduction reaction between Al(s) and Sn2+(aq) ?

3 Al(s) + 2 Sn2+ (aq) → 3 Al3+(aq) + 2 Sn(s)