Chemistry Final Review

Ion

An atom that has gained or lost one or more electrons. Has a positive or negative charge.

Octet Rule

Atoms like to have full valence shells of 8 electrons; noble gases are unreactive.

Cation

Loss of electrons

Anion

Gain of electrons

Do metals lose or gain electrons?

They lose electrons due to low ionization energy.

Do nonmetals lose or gain electrons?

They gain electrons due to high electron affinity.

Do the protons and neutrons change in an ion?

No, it stays the same as the parent atom.

Will an ion become a noble gas?

An ion will never become a noble gas regardless of the full electron shell.

What are the most reactive groups on the periodic table?

Alkali metals (group 1) and Halogens (group 17)

What are the characteristics of stable ions?

An ion will have different chemical properties compared to the parent atom, ions conduct electricity in water, and the electron configuration resembles a noble gas.

What group on the periodic table can form ions without a stable octet?

Transition Metals

Monatomic Ion

An ion with only one atom.

Polyatomic Ion

An ion with 2 or more atoms that functions as one.

How do you write an ionic formula?

Identify the charges and criss cross them.

What does the roman numeral in front of an ion mean?

It shows the charge of the ion.

In ionic formula writing, when do you use parentheses?

Around polyatomic ions with a charge greater than one.

What ending does a monatomic ion have?

\-ide

What ending does a polyatomic ion have?

\-ate or -ite

How do you name an ionic compound?

Use the name of the cation, and then use the name of the anion and change the ending to -ide.

What determines the strength of an ionic bond?

Size and Charge

Lattice Energy

The energy released when ions bond.

Do smaller or larger atoms release more lattice energy?

Smaller atoms because they are bonded closer together.

What structure do ionic compounds form?

A crystal lattice

What attracts two ions together?

The nucleus of one ion attracts electrons of neighbors.

What type of reaction is ionic bonding?

Exothermic Reaction

What does lattice energy measure?

Bond energy; the more energy released, the stronger the bond.

The smaller the ion ….

the greater the lattice energy.

What are some characteristics of ionic compounds?

high melting and boiling points, rarely gaseous, salts are hard and brittle

How do you calculate molar mass?

Add the masses of each element in a compound together (use the value on the periodic table).

How do you convert grams to moles?

Use the ratio 1mol/molar mass.

Avogadro’s Number

6\.022 x 10^23

How do you calculate empirical formulas?

Convert the percent to grams. (ex 60% is 60g). Multiply that by 1mol/molar mass. This will result in the smallest amount of moles. Finally, divide each value by the smallest amount of moles and round to the nearest whole number. Put it all together for the empirical formula.

What is an empirical formula?

It shows the simplest ratio between ions.

What is a molecular formula?

A whole number multiple of the empirical formula.

How to calculate a molecular formula?

Start with your empirical formula. Then find the molar mass of the compound. Divide the molar mass of the compound by the molar mass of the empirical formula. Multiple your empirical formula by the whole number that you receive.

How to calculate percent composition?

Find the molar mass of the compound. Divide the mass each element contributes by the total molar mass of the compound. Then multiply by 100. You can check your work by adding the percentages.

What number do you change to balance an equation?

You change the coefficient.

Why can’t you change the subscript when balancing equations?

You would end up changing the compound rather than balancing it.

What is a combustion reaction?

The reaction of a carbon based compound with oxygen. O2 would be in the reactant, and carbon dioxide and water are the products.

What is a synthesis reaction?

Two reactant form a single compound.

What is a decomposition reaction?

A single compound breaks down into two or more simpler elements.

What is a single-displacement reaction?

A single element displaces another element from a compound.

When do you use the activity series?

You use it to make predictions about displacement reactions?

Where are the most reactive metals located on the activity series?

Towards to top.

Where are the least reactive metals located on the activity series?

Towards the bottom.

What is a double-displacement reaction?

Two compounds in an aqueous solution switch ions.

What does S on the solubility table translate to?

Aqueous (aq)

What does I on the solubility table translate to?

Solid (s)

What is a solubility table useful for?

Determining whether or not a reaction occurred (it allows you to see whether a precipitate has formed).

What is the center of all stoichiometric problems?

The mole ratio

At STP what ratio are you able to use?

22\.4L/1mol

How many milliliters equal 1 liter?

1000

How to you convert a substance from grams to mols?

Multiple it by 1mol/molar mass.

What is a limiting reactant?

The compound in a reaction that runs out first, which limits how much of the products can be produced.

What is the excess reactant?

The compound in a reaction that has the larger amount of product formed.

How do you calculate limiting and excess reactant?

Choose a product from the equation. Do a stoichiometric problem for both reactants to get to the product.

What is theoretical yield?

The maximum quantity of product that a reaction could theoretically make if everything about the reaction works perfectly.

How do you calculate theoretical yield?

It would be the same value as your limiting reactant.

What is actual yield?

The amount of product that you made doing the experiment.

How do you calculate actual yield?

Multiply the percent yield by the theoretical yield.

What is percent yield?

How close you are to achieving the theoretical yield.

How do you calculate percent yield?

Divide the actual yield by the theoretical yield and multiply by 100.

What is Boyle’s law?

The inverse relationship between pressure and volume. P1V1=P2V2. As the pressure increases the volume decreases.

What is Charles’s Law?

The direct relationship between temperature and volume. As the temperature increases, the volume increases. V1/T1 = V2/T2

What is Gay-Lussac’s Law?

The direct relationship between temperature and pressure. As the temperature increases, the pressure increases.

What is the ideal gas law?

The relationship between the volume, pressure, and temperature of a gas. PV=nRT

What is the combined gas law?

P1V1/T1 = P2V2/T2

Will a gas ever be ideal?

No, it’s an imaginary gas whose particles are infinitely small and do no interact with each other.

What is Dalton’s law of partial pressure?

The total pressure of a mixture of gases is the sum of the partial pressures of the gases. Just add the pressure of all the gases, to get the total pressure.

What is pressure?

The amount of force exerted per unit area of surface.

What is the SI unit of pressure?

Pascals

What is the standard pressure?

1 atm or 760mmHg

What causes air pressure?

Collisions of gas molecules.

What is the kinetic-molecular theory?

Gas particles are in constant rapid, random motion. The particles of a gas are very far apart relative to their size.

What does the R stand for in the ideal gas law?

The universal gas constant.

How was the universal gas constant derived?

Using Avogadro’s number.