CHE 2C Midterm 2 Material

Why are some alkali metals often used to produce color in fireworks?

The change in E matches wavelengths of visible light, giving off color.

The weak bonding of alkali metals causes it to be ______ metals, have ____ densities, and _____ melting points.

soft, low, low

Oxide Ion

O^2-

Peroxide Ion

O₂^2-

Superoxide Ion

O₂^-

Hydrogen becomes liquid at what temperature?

20K

Why does hydrogen need such a low temperature to become liquid?

low London forces

What are alkaline earth metals generally reactive towards?

water and air

Alkaline earth metals have _______ densities, _______ mps, and ______ bps.

low, low, low

Alkaline earth metals are ________ substances that do not decompose upon heating.

insoluble

How are alkaline earth metals generally produced?

reduction or electrolysis

What is concrete made of?

CaO+sand+gravel+water

What is chalk or limestone made of?

calcium carbonate

At high temperatures, what does chalk or limestone decompose to form?

quicklime and carbon dioxide gas

What is the most abundant metal?

Aluminum

What is the most abundant nonmetal?

O2

Group 13 elements (B, Al, Ga, In, Tl)

Icosagen

Dimers

the joining of two identical or similar monomers

Inert Pair Effect

s electrons are sometimes so unreactive that they become inert and are essentially considered core electrons (doesn’t react)

Common oxidation state of icosagens

+1 and +3

Group 14 elements (C, Si, Ge Pb, Sn)

Tetragens

Common oxidation states of tetragens

+2 and +4

Primary Intermolecular Force of He

LDF

Group 18 (He, Ne, Ar, Kr, Xe, Rn)

Noble Gases

Characteristics of Noble Gases

odorless, colorless, monatomic

What kind of atom do you need to form a bond with noble gases?

A highly EN atom

Which noble gas is most likely to form compounds?

Xe

Group 17 (F, Cl, Br, I, At)

Halogens

Which halogen is most reactive?

F

Which halogen is least reactive?

I

Halogens with oxygen form ________.

oxy acids

HOX Oxidation State

+1

HOX

Hypohalous acid

HOXO Oxidation State

+3

HOXO

Halous acid

HOXO2 Oxidation state

+5

HOXO2

Halic acid

HOXO3 Oxidation state

+7

HOXO3

Perhalic acid

Group 16 (O, S, Se, Te, Po)

Chalcogens

Group 15 (N, P, As, Sb, Bi)

Pnictogens

Phosphorus Common Oxidation state

+3 and +5

Arsenic

metalloid with various allotropes, used to strengthen alloys, semiconductor

What is arsenic used in?

pesticides, herbicides, and insecticides

What is antimony commonly used in?

solders, bullets, bearings, fire retardants

Class of compounds composed of B and H atoms

borane

What does the rate constant depend on?

reaction, temperature, catalyst

Reaction speed when r and k are small

slow

Reaction speed when r and k are large

fast

Collision Theory

1. A and B need to hit directly

2. A and B need to enter with a combined kinetic energy that is high enough to make a bond formation a viable result

3 Aspects of the Collision Theory

Collision frequency, activation energy, orientation

Collision Frequency

number of molecular collisions per unit time

Activation Energy

minimum energy above which the average kinetic energy molecules must bring to a collision in order to make a reaction happen

Orientation

molecules must enter a collision at the correct orientation in space in order for a reaction to occur.

___________ is increasingly importatn as the molecules increase in complexity

orientation

Element used in batteries, ammunitions, and pipies. It used to be in paint, gasoline, and pencils

Pb

Element found in concrete, chalk, limestone, and hard water

Ca

Element is usual for its family because it is unreactive to water and air and has a high ionization energy; it also forms dimers with Cl

Be

Element most abundant in the universe and it is used as fuel for space shuttles

H

Element is opaque to x-rays and it is also toxic and insoluble in the human body

Ba

Group of elements that are easily oxidized and readily forms oxides, peroxides, and superoxides.

Alkali Metals

Noble gas that emits light under a current

Ne

Element with +2 and +4 as common oxidation states and is used in solders and pewter.

Sn

Element used in fertilizers and mustard gas; it is responsible for the smell of skunks

S

Element used in inert atmosphere for reactions sensitive to water and oxygen, but it is also used in explosive reactions

N

Element used to dilute H2 and O2 to decrease flammability; it is also so light that it can escape the atmosphere

He

Element that is the most abundant metal in Earth’s crust, and it forms many prized gems such as rubies, sapphires, and topazes.

Al

Element that is chemically similar to Si and Sn and it is used industrially as a semiconductor

Ge

Noble gas abundant in the air and it is used in radioactive dating

Ar

Element abundant in the air and it forms a compound that protects us from UV rays. Transfers energy to N2 in the atmosphere in the form of kinetic energy.

O

Element used in glass, zeolites, oils, and high-temperature lubricants

Si

Element used as dopant in the semiconductor industry and it is used in glassware

B

Element found in ATP and ADP and it is also used as fertilizer

P

Noble gas that is a product of fission and it is used to measure the worldwide nuclear activity

Kr

Group of elements that can be found in Teflon, Freon, and PVC

Halogens

Element essential to life due to its ability to form strong bonds with itself and other atoms

C

Hydrogen forms what type of bonds with nonmetals?

covalent

Oxides of metals are ________ (basic/acidic) except for beryllium oxide, which is ____________.

basic; amphoteric

Amphoteric

able to react as both an acid and a base

The elements in Group 3A all act as active metals except _________.

Boron

What are some metallic properties of Aluminum?

conducts heat and electricity; lustrous appearance

What is responsible for the amphoteric nature of Al2O3 and the acidic nature of Al(H2O)6 3+?

Aluminum forms covalent bonds with nonmetals

What element has the largest liquid range of any metal and expands when it freezes?

Ga

Al2O3 and Ga2O3

Amphoteric Oxides

What ions are very important for the proper functioning of biologic systems, such as nerves and muscles?

alkali metals

For nonmetals, the lower the molar mass, the ______ the melting point.

lower

For metals, the lower the molar mass, the ________ the melting point

higher

Which alkaline earth metals react vigorously with water at 25C?

Ca, Sr, Ba

At what temperature does Mg react with water?

100C

Which element concentration is high in human blood plasma?

Na

Which element concentration is high in fluids inside the cell?

K

Hydrides

binary compounds containing hydrogen

What are the 3 classifications of hydrides?

ionic hydrides, covalent hydrides, and metallic hydrides

How are ionic hydrides formed?

When it reacts with the most active metals (Groups 1A and 2A)

How is oxygen and nitrogen converted to liquid?

Liquefaction

Alkaline metals that are more _________ react with water

active

Which two alkaline earth metals do not react with water?

Be and Mg

Hard water

Natural water than contains Ca2+ and Mg2+ interfere with the action of detergents and forms precipitates with soap

Ion exchange

process that removes Ca2+ and Mg2+ in individual homes; Na+ is released into the solution

Nitrogen fixation

transforms nitrogen to other nitrogen containing compounds