Physical Science - Chemistry Final Review Flashcards

Compendium of practice questions and answers covering chemical formulas, balanced equations, reaction types, periodic trends, atomic structure, and electron configurations based on a Physical Science Chemistry final exam transcript.

How many atoms of fluorine are in a molecule of carbon tetrafluoride ($CF_4$)?

$4$ atoms

What is the formula mass of magnesium chloride, $MgCl_2$?

$$95.21\,amu$$

Define empirical formula.

A formula that shows the simplest whole-number ratio of the atoms in a compound.

What is required to find the molecular formula from the empirical formula?

The compound's formula mass.

What is a precipitate?

A solid produced by a chemical reaction that separates from the solution.

What is the correct representation of hydrogen gas in a chemical equation?

$$H_2$$

What is a coefficient in a chemical equation?

The small whole number that appears in front of a formula in a chemical equation.

According to the law of conservation of mass, how does the mass of reactants compare to the mass of products?

The total mass of the reacting substances is always equal to the total mass of the products.

When is a chemical equation considered balanced?

When the same number of each kind of atom appears in the reactants and in the products.

What does the symbol $(aq)$ represent in a chemical equation?

A substance in water (aqueous) solution.

What are the coefficients for the balanced equation: $NH_4NO_2(s) \rightarrow N_2(g) + H_2O(l)$?

$$1, 1, 2$$

Define synthesis reaction.

A reaction in which two or more substances combine to form a new compound ($A + X \rightarrow AX$).

Define decomposition reaction.

A reaction in which a single compound produces two or more simpler substances ($AX \rightarrow A + X$).

Define single-displacement reaction.

A reaction in which one element replaces a similar element in a compound ($A + BX \rightarrow AX + B$).

Define double-displacement reaction.

A reaction in which the ions of two compounds exchange places in aqueous solution to form two new compounds ($AX + BY \rightarrow AY + BX$).

What is an activity series?

A list of elements arranged according to the ease with which they undergo certain chemical reactions; an element can replace any element below it on the list.

What are the vertical columns and horizontal rows on the periodic table called?

Vertical columns are called groups; horizontal rows are called periods.

What is the periodic law?

The principle that states that the physical and chemical properties of the elements are periodic functions of their atomic numbers.

Define alkali metals.

A group of soft, silvery, reactive metals, all of which have one electron in an $s$ orbital.

Define ionization energy.

The energy required to remove an electron from an atom.

Define electronegativity.

A measure of the ability of an atom in a chemical compound to attract electrons from another atom.

Define atomic radius.

One-half the distance between the nuclei of identical atoms that are bonded together.

Differentiate between a cation and an anion.

A cation is a positive ion; an anion is a negative ion.

What is the trend for atomic radius across a period and down a group?

Atomic radius generally decreases across a period and increases down a group.

What is the molar mass of magnesium iodide, $MgI_2$?

The sum of the masses of $1\,mol$ of $Mg$ and $2\,mol$ of $I$.

How many molecules are present in $0.500\,mol$ of $CO_2$?

$$3.01 \times 10^{23}$$

Whose experiments identified the nucleus of the atom?

Rutherford

Why is an atom electrically neutral?

Because the numbers of protons and electrons are equal.

What are isotopes?

Atoms of the same element that have different masses (different numbers of neutrons).

What does the atomic number of an element indicate?

The number of protons in the nucleus of an atom of that element.

What is the ground state of an atom?

The state in which electrons in an atom have the lowest possible energies.

According to the Bohr model, how do electrons circle the nucleus?

In specific, allowed orbits.

Define orbital.

A three-dimensional region around a nucleus where an electron may be found.

Define Hund's rule.

The rule requiring that each of the $p$ orbitals at a particular energy level receive one electron before any of them can have two electrons.

What is the filling order of atomic orbitals according to the Aufbau principle?

$$1s \rightarrow 2s \rightarrow 2p \rightarrow 3s \rightarrow 3p \rightarrow 4s \rightarrow 3d \rightarrow 4p \rightarrow 5s$$

What is the electron configuration for Nitrogen ($Z = 7$)?

$$1s^2 2s^2 2p^3$$

What is the balanced chemical equation for the reaction: $iron + copper(I)\,nitrate \rightarrow iron(II)\,nitrate + copper$?

$$Fe(s) + 2CuNO_3(aq) \rightarrow Fe(NO_3)_2(aq) + 2Cu(s)$$

What is the chemical formula for dinitrogen tetroxide?

$$N_2O_4$$

How much does $3.5\,moles$ of $NaCl$ weigh?

$$204.8\,g$$

What is the electron configuration for Titanium ($Ti$) in spectroscopic and shorthand notation?

Spectroscopic: $1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^2$; Shorthand: $[Ar] 4s^2 3d^2$