SCH3U Test #2 (Ch. 3+4)

Question 1

What are the melting points of ionic compounds vs. molecular compounds?

Answer 1

Ionic = high melting pt, molecular = low melting pt.

Question 2

What are the conductivity levels of ionic vs. molecular/covalent compounds as liquids?

Answer 2

Ionic = high conductivity, covalent = low conductivity

Question 3

What are the states at room temperature of molecular/covalent vs. ionic compounds?

Answer 3

Molecular = solid, liquid or gas Ionic = crystalline solid

Question 4

What is the solubility in water of ionic compounds vs. molecular compounds?

Answer 4

Ionic = high solubility, molecular = low solubility (both are tentative)

Question 5

What are the electrical conductivities when dissolved in water of molecular vs. ionic compounds?

Answer 5

Covalent = not usually conductive, ionic = conductive

Question 6

What type of chemical reaction is this: Pb(NO3)2 + 2 KI —> PbI2 + 2 KNO3

Answer 6

Double Displacement

Question 7

What type of chemical reaction is this: 2 H2O —> 2 H2 + O2

Answer 7

Decomposition

Question 8

What type of chemical reaction is this: 8 Fe + S8 —> 8 FeS

Answer 8

Synthesis

Question 9

What type of chemical reaction is this: C10H8 + 12 O2 —> 10 CO2 + 4 H2O

Answer 9

Combustion

Question 10

What type of chemical reaction is this: Mg + 2 H2O —> Mg(OH)2 + H2

Answer 10

Single Displacement

Question 11

What will be the products of the following reaction: HBr + NaOH —>

Answer 11

HBr + NaOH —> NaBr + H2O (acid/base reaction produces water)

Question 12

What will be the product(s) of the following reaction: 2 H2O —>

Answer 12

2 H2O —> 2 H2 + O2

Question 13

What will be the product(s) of the following reaction: 8 Fe + S8 —>

Answer 13

8 Fe + S8 —> 8 FeS

Question 14

What will be the product(s) of the following reaction: Pb(NO3)2 + 2 KI —>

Answer 14

Pb(NO3)2 + 2 KI —> PbI2 + 2 KNO3

Question 15

What will be the product(s) of the following reaction be? C10H8 + 12 O2 —>

Answer 15

C10H8 + 12 O2 —> 10 CO2 + 4 H2O

Question 16

Predict the products of the following reaction: Mg + 2 H2O —>

Answer 16

Mg + 2 H2O —> Mg(OH)2 + H2

Question 17

What are the 5 different shapes of polar molecules?

Answer 17

Linear, angular/bent, trigonal pyramidal, trigonal planar, tetrahedral.

Question 18

What shape of molecule is this?

Answer 18

Trigonal pyramidal

Question 19

What shape of molecule is this?

Answer 19

Trigonal planar

Question 20

What shape of molecule is this?

Answer 20

Tetrahedral

Question 21

Are trigonal planar molecules symmetrical?

Answer 21

No, they are asymmetrical because of the lone electron pair on the central atom.

Question 22

Are tetrahedral molecules symmetrical?

Answer 22

They are symmetrical if the non-central atoms are the same.

Question 23

Are trigonal planar molecules symmetrical?

Answer 23

They are typically asymmetrical unless the 3 non-central atoms are the same.

Question 24

What is the electronegativity difference between atoms in a polar bond?

Answer 24

Anywhere from 0.5-1.7