General Science

Coefficient (in a Reacation)

a number placed in front of a chemical symbol or formula that indicates the number of atoms or molecules needed for a reaction

Inert Element

an element that rarely reacts with other elements

Viscosity

the resistance to flowing

solute

the material in a solution that is dissolved in the solvent (Sugar)

rate of dissolution

how fast a solute dissolves in a solvent

solution

a mixture in which one substance dissolves in another

alkalinity

the concentration of hydroxide in solution, increased alkalinity corresponds to high pH

valence electron

an electron in the outermost shell of an atom in the ground state; the only type of electron involved in bonding

aqueous

chemical substances dissolved in water

density

the amount of mass present in a given volume, reflection of how tightly packed the atoms are

mixture

a substance in which the atoms, molecules or particles of two or more different materials are mixed but not chemically combined

heterogeneous mixture

a mixture that is not uniformly mixed

freezing point depression

adding solute to lower the freezing temperature

periodic table

a chart of the elements, organized by physical and chemical properties of different types of atoms

reaction: single replacement

one element or molecule replaces another element in a molecule

AB + C —> AC + B

Reaction: Neutralization

reaction in which when an acid and base chemically react and form a salt and water with a resulting pH of 7

acid + base —> water + salt

solvent

a substance which dissolves other substances (water)

reaction: decomposition

1 molecule is broken down into 2 separate elements or molecules

AB —> A + B

period (on periodic table)

each row on the perioidc table

mole fraction

a method of representing concentration as a ratio of the total moles in the solution

group (on periodic table)

each column on the periodic table

Dimensional Analysis

the process of converting within or between systems by multiplying by factors of 1 in various forms

solubility

the ability of a substance to be dissolved in a solvent

Reaction: Redox

reaction in which electrons transfer, causing the oxidation number to change

osmotic pressure

a pressure that causes movement of water through a semipermeable membrane towards the side with a greater solute concentration

Reaction: Double Replacement

elements in molecules replace each other

AB + CD —> AC + BD

Boiling point elevation

adding solute to increase the boiling temperature

salinity

a measure of the amount of salts that are dissolved in water

acidity

the concentration of hydrogen ions in a solution, high acidity corresponds to low pH

colligative

properties that depend only on the mole fraction of the solute (freezing point depression)

chemical equations

notation that shows how 2 molecules or compounds react together to form a product

Family (on a periodic table)

each column on the perodic table

Reaction: Combination

2 elements or molecules combine to form 1 molecule

Non-Colligative

properties that depend only on the identity of the solute

oxidation number

the charge of an atom

homogeneous mixture

a mixture with the same ratio of parts throughout the mixture

Conservation of Matter

matter cannot be created nor destoryed; it ony changes form

Stoichiometry

uses a balanced equation to determine the amount of reactants needed to create a certain amount of product or how much product can be created from a set amount of reactant

pure substance

a substance that consists of only one type of atom or molecule

chemical reaction

a reaction that forms a new substance by rearranging the atomic bonds between atoms. The process absorbs energy during bond breaking and releases energy during bond making

reactants

the starting substances in a chemical reaction

Reaction: Combustion

a compound containing carbon reacts with oxygen and burns releasing carbon dioxide

Molarity

a measure of concentration; the number of moles of solute per liter of solution

vapor pressure

the pressure exerted by gas phase molecules at the surface of a liquid

products

the resulting substances in a chemical reaction

Which of the following represents a combustion reaction?
a) MgO + C → Mg + CO
b) 2C₄H₁₀ + 13O₂ → 8CO₂ + 10 H₂O
c) 2HCl + Zn → ZnCl₂ + H₂
d) 3HCl + Fe(OH)₃ → 3H₂O + FeCl₃

b) 2C₄H₁₀ + 13O₂ → 8CO₂ + 10 H₂O

A student adds 5 grams of NaCl to a saturated solution at 25 ^oC and observes white crystals at the bottom of the container. When the solution is heated to 50 ^oC, the crystals disappear. Which of the following explains this observation?
a) NaCl is less dense at a warmer temperature.
b) Solubility increases as temperature increases.
c) Water is more dense at a lower temperature.
d) Solubility increases as pressure increases.

b) Solubility increases as temperature increases.

Plants create energy with the help of sunlight through the process of photosynthesis. In this reaction, carbon dioxide and water combine to form glucose and oxygen gas. Which of the following balanced chemical reactions accurately represents this process?
a) 12CO2 + 11H2O —> C12H22O11 + 12O2
b) 6CO2 + 6H2O —> C6H12O6 + 3O2
c) 12CO2 + 11H2O —> C12H22O11 + 12O2
d) 6CO2 + 6H2O —> C6H12O6 + 6O2

d) 6CO2 + 6H2O —> C6H12O6 + 6O2

Which of the following chemical equations is balanced correctly using lowest whole-number coefficients?
a) CH₄ (g) + H₂O (g) → CO (g) + 3H₂ (g)
b) 2CH₄ (g) + 4O₂ (g) → 2CO₂ (g) + 4H₂O (g)
c) H₂O (g) + 2C (s) → 2H₂ (g) + 2CO (g)
d) 2CO₂ (g) + C (s) → 4CO (g)

a) CH₄ (g) + H₂O (g) → CO (g) + 3H₂ (g)

Silicon carbide is an abrasive material formed from the reaction of silicon dioxide and graphite. How much graphite will remain if 75.0 g of each reactant are reacted to completion in the given chemical equation?

SiO2+3C→SiC+2COSiOX2​+3C​SiC+2CO

30 g

Which of the following accurately describes calcium's placement on the periodic table?
a) group 2, period 2
b) group 4, period 4
c) group 2, period 4
d) group 4, period 2

c) group 2, period 4

The Haber Process makes ammonia from pure nitrogen and hydrogen gas at 545 K and 385 atm in the following equation.

2N₂ (g) + 3H₂ (g) → 2NH₃ (g)

How much H₂ (rounded to the nearest tenth of a liter) is needed to produce 7.01 moles of NH₃ (g) with excess N₂.

1.22L

How can elements in group 1 be compared to elements in group 18?
a) Elements in group 1 include helium and argon, while elements in group 18 include lithium and sodium.
b) Elements in group 1 contain full valence shells, while elements in group 18 are chemically active.
c) Elements in group 1 are chemically active, while elements in group 18 are chemically inert.
d) Elements in group 1 contain eight valence electrons, while elements in group 18 contain one valence electron.

c) Elements in group 1 are chemically active, while elements in group 18 are chemically inert.

A sample of H₂SO₄ contains 4.75 × 10²⁴ atoms of oxygen. How many moles of H₂SO₄ is the sample?

1.97 mol H₂SO₄

When the following equation is balanced using the smallest whole-number ratios, what is the correct coefficient for O₂?

C₂₁H₂₄N₂O₄ + O₂ → CO₂ + H₂O + NO₂

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H

Hydrogen
Protons: 1
Electrons: 1
Valence e: 1
Period: 1
Group/Family: 1

He

Helium
Protons: 2
Electrons: 2
Valence e: 2
Period: 1
Group/Family: 18/Nobel Gases

Li

Lithium
Protons: 3
Electrons: 3
Valence e: 1
Period: 2
Group/Family: 1/Alkaline metal

Be

Beryllium
Protons: 4
Neutrons: 4
Electrons: 4
Period: 2
Group/Family: 2/Alkaline Earth Metals

B

Boron
Protons: 5
Electrons: 5
Valence e: 3
Period: 2
Group/Family: 3A/13-Metalloid

C

Carbon
Protons: 6
Electrons: 6
Valence e: 4
Period: 2
Group/Family: 4A/14 nonmetals

N

Nitrogen
Protons: 7
Electrons: 7
Valence e: 5
Period: 2
Group/Family: 5A/15-nonmetals

O

Oxygen
Protons: 8
Electrons: 8
Valence e: 6
Period: 2
Group/Family: 6A/16- Nonmetals

F

Fluorine
Protons: 9
Electrons: 9
Valence e: 7
Period: 2
Group/Family: 7A/17- Halogen

Ne

Neon
Protons: 10
Electrons: 10
Valence e: 8
Period: 2
Group/Family: 8A/18- Nobel Gas

Na

Sodium
Protons: 11
Electrons: 11
Valence e: 1
Period: 3
Group/Family: 1: Alkali metal

Mg

Magnesium
Protons: 12
Electrons: 12
Valence e: 2
Period: 3
Group/Family: 2: Alkali Earth metals

Al

Aluminum
Protons: 13
Electrons: 13
Valence e: 3
Period: 3
Group/Family: 3A/13- post transition metal

Si

Silicon
Protons: 14
Electrons: 14
Valence e: 4
Period: 3
Group/Family: 4A/14- Metalloid

P

Phosphorus
Protons: 15
Electrons: 15
Valence e: 5
Period: 3
Group/Family: 5A/15- Nonmetals

S

Sulfur
Protons: 16
Electrons: 16
Valence e: 6
Period: 3
Group/Family: 6A/16- Nonmetals

Cl

Chlorine
Protons: 17
Electrons: 17
Valence e: 7
Period: 3
Group/Family: 7A/17- Halogen

Ar

Argon
Protons: 18
Electrons: 18
Valence e: 8
Period: 3
Group/Family: 8A/18- Nobel Gas

K

Potassium
Protons: 19
Electrons: 19
Valence e: 1
Period: 4
Group/Family: 1- Alkali metals

Ca

Calcium
Protons: 20
Electrons: 20
Valence e: 2
Period: 4
Group/Family: 2- Alkali Earth metal

Ti

Titanium
Protons: 22
Electrons: 22
Valence e: 4
Period: 4
Group/Family: 4B/4: Transition

Cr (basic)

Chromium
Protons: 24
Transition metal

Mn (basic)

Manganese
Protons: 15
Transition metal

Fe

Iron
Protons: 26
Electrons: 26
Valence e: 8
Period: 4
Group/Family: Transition

Co

Cobalt
Protons: 27
Electrons: 27
Valence e: 9
Period: 4
Group/Family: Transition metal

Ni

Nickel
Protons: 28
Electrons: 28
Valence e: 10
Period: 4
Group/Family: Transition meta

Cu

Copper
Protons: 29
Electrons: 29
Valence e: 11
Period: 4
Group/Family: Transition

Zn

Zinc
Protons: 30
Electrons: 30
Valence e: 12
Period: 4
Group/Family: Transition metal

Ga

Gallium
Protons: 31
Electrons: 31
Valence e: 13
Period: 4
Group/Family: post transition metals

Ge

Germanium
Protons: 32
Electrons: 32
Valence e: 14
Period: 4
Group/Family: Metalloid

As

Arsenic
Protons: 33
Electrons: 33
Valence e: 15
Period: 4
Group/Family: Metalloid

Br

Bromine
Protons: 35
Electrons: 35
Valence e: 17
Period: 4
Group/Family: Halogen

Kr

Krypton
Protons: 36
Electrons: 36
Valence e: 18
Period: 4
Group/Family: Nobel Gas

Sr

Strontium
Protons: 38
Electrons: 38
Valence e: 2
Period: 5
Group/Family: Alkali Earth metal

Ag

Silver
Protons: 47
Electrons: 47
Valence e: 11
Period: 5
Group/Family: transition

Sn

Tin
Protons: 50
Electrons: 50
Valence e: 14
Period: 5
Group/Family: post transition metal

Sb

Antimony
Protons: 51
Electrons: 51
Valence e: 15
Period: 5
Group/Family: Metalloid

I

Iodine
Protons: 53
Electrons: 53
Valence e: 17
Period: 5
Group/Family: Halogen

Xe

Xenon
Protons: 54
Electrons: 54
Valence e: 18
Period: 5
Group/Family: Nobel gas

Ba

Barium
56
Alkali Earth

W

Tungsten
74
transition metal

Pt

Platinum
78
transition

Au

Gold
79
transition metal

Hg

Mercury
80
transition

Pb

Lead
82
post transition metal