Ch 22 Bonding in Ionic Compounds

In Lesson 20, a magnesium strip was used to ignite the thermite reaction. When magnesium is placed in a flame from a small blow torch, it burns quite brightly forming magnesium oxide, a salt that contains one magnesium for every oxygen. In the following questions you will be asked to provide some details of the chemical processes involved in a reaction between magnesium and oxygen. How many more electrons does unbound oxygen need to fill its 2nd shell? (You may find it helpful to draw the energy well on scratch paper.)

2

Which of the following is a correct and balanced equation showing the reaction of calcium and oxygen? (While several of the equations may be balanced, only one has the correct products and reactants as well as being correctly balanced.) Ca + O2 = CaO, Ca + O2 = CaO2, 2Ca + O2 = 2CaO, 4Ca + O2 = 2Ca2O, Ca + O2 = Ca2O

2Ca + O2 = 2CaO

The atomic orbitals for potassium and bromine are similar to those for sodium and chlorine in that the potassium orbitals are higher in energy than their counterparts on bromine. Why is this?

Bromine valence electrons experience a stronger attraction to their nucleus because of smaller atomic volume and increased nuclear charge.

What happens to the entropy of the universe as the products are formed?

Chemical potential energy is converted into thermal energy resulting in an increase in entropy.

The chemical bond that binds metallic ions to non-metallic ions by electrical attraction.

Ionic Bonding

The correct formula for sodium chloride is:

NaCl

Phosphorus is a non-metal found on the right-hand side of the Periodic Table. Using the Periodic Table, determine the ion most likely to form from this non-metal.

P3-

a substance formed from the ionic bond of a metal with a non-metal

Salt

Strontium is a metal found on the left-hand side of the Periodic Table. Using the Periodic Table, determine the ion most likely to form from this metal.

Sr2+

aluminum Chloride is an ionic compound with a formula of alcl3. What is likely to be true concerning the structure of alcl3?

The ions will arrange themselves in the most energetically favorable arrangments with ions of one charge surrounded by ions of the opposite charge.

What happens to the valence electrons as the product (MgO) is formed?

The magnesium atoms' valence electrons are effectively transferred to oxygen.

T/F: Metals easily lose electrons.

True

T/F: Molten salts are ionic conductors.

True

T/F: a salt is electrically neutral as a solid.

True

Each ion of an ionic compound has the ions of the [blank] charge as its next-door neighbors.

opposite

[Blank] combine with non-metals to form highly-colored compounds.

transition metals

a characteristic of salts that readily transmit light; opposite of opaqueness

transparency

What is the charge of iron (Fe) in the compound Fe2O3?

+3

Which of the following would best describe the room temperature characteristics of the magnesium oxide? Brittle, opaque, solid. Electrically conducting alloy. Transparent gas. A malleable solid. Brittle, transparent, electrically non-conducting solid.

Brittle, transparent, electrically non-conducting solid

T/F: Electrons like to go to the higher energy condition available to them.

False

T/F: Ionic compounds have extremely low melting temperatures.

False

T/F: Salts can easily be flattened or reshaped.

False

The most energetically favorable arrangement of ions maximizes [blank] forces and minimizes repulsive ones.

attractive

a characteristic of ionic substances, such as salts, that readily shatter when struck a sharp blow

brittleness

a chemical compound that ionizes when dissolved or molten to produce an electrically conductive medium.

electrolytes

Metals lose [blank] to form positive ions.

electrons

a charged particle formed when an atom or molecule loses or gains electrons.

ion

For a given period, metals have [blank] atomic volumes, where as non-metals have [blank] atomic volumes.

large, small

Electrons go to the [blank] energy condition available to them.

lowest

When writing down the chemical formula for a salt, the [blank] symbol is written first and the [blank] is written last.

metal, non-metal