Potions and Poisons

Potions and Poisons is a Division B event that is set to rotate in for the 2018 season. It was previously a trial event in Pennsylvania and Washington. In Potions and Poisons, participants will demonstrate their knowledge on specified substances' chemical properties and effects with a focus on common toxins and poisons. Category C goggles are required in this event.

Topics covered
These are some of the Potions and Poisons topics as of the most recent version of the trial event rules released by the national committee in the summer of 2016:
 * Chemical bonding
 * Mixtures, solutions and compounds and separation of the components within them
 * Property changes
 * Chemical equations
 * Balancing chemical equations
 * Poisonous plants and animals
 * Common household toxins
 * Environmental toxins and effects of their spread
 * Effects of dilution
 * Lab tasks

Chemical bonding
A chemical bond is an attraction between two atoms that causes them to combine, which can create molecules. The two types of bonding that the current version of the Potions and Poisons rules says to know are ionic and covalent bonding.

Electronegativity
Electronegativity is a property of elements that is defined as the tendency of an atom to attract electrons. The difference between two atoms' electronegativities decides the type of bond they make. A chart known as an electronegativity chart can be used to find the electronegativities of different elements

Ionic Bonding
Ionic bonding is a type of bonding in which one atom takes an electron from another atom. This type of bonding occurs when the difference in electronegativity is high. A common example of this is the compound NaCl, or table salt. The metal Na (sodium) bonds with the halogen gas Cl (chlorine).

To name a simple ionic compound, use the name of the regular metal, followed by the name of the nonmetal, with the latter using the ending "-ide". For example, NaCl would be written as sodium chloride.

Covalent Bonding
Covalent bonding is a type of bonding in which atoms 'share' electrons. This occurs when there is a low difference in electronegativity. Two very common examples are the molecules H2; and O2;. Because the bonds are formed between two atoms of the same element, the difference in their electronegativities must be zero.

Covalent bonds can be nonpolar or polar. In polar covalent bonds, the atoms have different electronegativites, and therefore share electrons unequally. The more electronegative atom has a partial negative charge, while the less electronegative atom has a partial positive charge. These are denoted with the &#948; symbol (Greek lowercase delta), using &#948;- for partial negative charge and &#948;+ for partial positive charge.

Chemical Equations
Chemical reactions are written out as chemical equations. A chemical equation has two parts: reactants and products. The atoms in the reactants are rearranged to form the products.

Chemical equations are written left-to-right with the products following the reactants, and an arrow sign (which is read as "yields") pointing from the reactants to the products. Each individual reactant/molecule is represented with a plus sign (+). The following equation is an example of a chemical equation, with the reactants on the left and the product on the right.

[math]2H_2 + O_2 \rightarrow 2H_2O[/math]

If there are multiple instances of a molecule, the number of molecules is written as a coefficient. For example, the product in the above equation is water, or H&#8322;O. There are two water molecules present, which is written as 2H&#8322;O.

Balancing Chemical Equations
In a chemical reaction, the quantity of each element cannot change (If there are n atoms of element A in the reactants, there must be n atoms in the product). A chemical equation must have equal quantities of each element on either side of the arrow. As mentioned above, adding coefficients to molecules can show that there are those many molecules present. However, if an equation is given without coefficients, chances are that there is an inequality on either side. Consider the example given above; however this time it is without coefficients:

[math]H_2 + O_2 \rightarrow H_2O[/math]

If you count the number of each element on either side of the equation, you will get the following: This cannot be a balanced equation, because the number of atoms is unequal. To fix this issue, it is necessary to balance the chemical equation.
 * Hydrogen on left: 2
 * Oxygen on left: 2
 * Hydrogen on right: 2
 * Oxygen on right: 1

To balance a chemical equation, add coefficients to make the number of atoms of each element equal. For example, take again the previous equation:

[math]H_2 + O_2 \rightarrow H_2O[/math]

Notice that there is only one type of molecule as the product, meaning that it is the only molecule that a coefficient can be added to. A basic way to find the proper coefficient is to find a ratio between the two elements on one side and apply that to the other side. In this example, there are two times as many hydrogens as oxygens. In addition, all coefficients must be whole numbers. Therefore, the lowest coefficients would be a two in front of the hydrogen gas (on the left) and a two in front of the water. This gives us a balanced equation of:

[math]2H_2 + O_2 \rightarrow 2H_2O[/math]

Poisonous Plants and Animals
The poisonous plants and animals listed in the trial rules are:
 * Poison ivy (Toxicodendron radicans)
 * Wolfsbane (Aconitum sp.)
 * Jack in the pulpit (Arum maculatum)
 * Lily of the valley (Convallaria majalis)
 * Poison sumac (Toxicodendron vernix)
 * Cane toad (Rhinella marina)
 * Poison dart frog (Dendrobates sp.)
 * Portuguese man o' war (Physalia physalis)
 * Fattail scorpion (Androctonus australis)

Common Household Toxins
The trial rules of Potions and Poisons mention the following toxic household chemicals:
 * Ammonia
 * Hydrogen peroxide
 * Rubbing alcohol
 * Bleach
 * Epsom salts
 * Vinegar
 * Nutritional supplements containing calcium and iron

Ammonia
The compound ammonia itself is a colorless gas with the formula NH3. However, it is most commonly seen in households as a cleaner, where the gas is dissolved into water. It is most dangerous when mixed with bleach, which causes the release of toxic fumes, which can cause serious respiratory damage, in addition to potential chemical burns, headaches, nausea, or vomiting.

Hydrogen peroxide
Hydrogen peroxide is a colorless liquid with the formula H2O2. It is commonly used as a disinfectant, either for surfaces or for wounds. Because the concentration of most hydrogen peroxide used in households (usually in brown bottles) is low, at about 3%, ingestion of small amounts of hydrogen peroxide (diluted) does not usually cause any significant damage, apart from potential stomach irritation. However, ingesting a large quantity can cause more serious stomach irritation and may even cause chemical burns.

Furthermore, ingestion of a higher concentration of hydrogen peroxide can cause much more serious symptoms, and death in some cases.

Rubbing Alcohol
Rubbing alcohol (Isopropyl alcohol) is an alcohol with the formula C3H8O. It is most often used as a disinfectant. When ingested, it is metabolized into acetone. This can cause dizziness, headaches, vomiting, or even coma.

Bleach
Bleach is a solution of the chemical compound sodium hypochlorite (NaClO) in water. It is a strong base, with a pH of 12.6. It is most often used as a household cleaner. As mentioned above, mixing bleach with ammonia releases dangerous fumes. Exposure to bleach on its own can cause irritation in the eyes, mouth, skin, and lungs, and can cause burns.

Epsom Salts
Epsom salts (Magnesium sulfate) are salts with the equation MgSO4. They have many uses, including uses as bath salts, as laxatives, face cleansers, cleaners, and as fertilizer. However, ingesting high levels of these salts can cause magnesium overdose, which can lead to slowed heartbeat, lowered blood pressure, nausea, vomiting, and coma or death in serious cases.

Vinegar
Vinegar is an extremely common household chemical. It is an acidic liquid, a mixture of acetic acid (CH3COOH) and water. It is used in cooking, cleaning, and medicine. However, concentrations of acetic acid higher than 10% can cause skin damage/corrosion.

Dilution
Dilution is simply the addition of a solvent without adding any solute. This is shown in the equation:

[math]C_1 \times V_1 = C_2 \times V_2[/math]

where
 * C1 = the initial concentration of the solute
 * V1 = the initial volume of the solution
 * C2 = the final concentration of the solute
 * V2 = the final volume of the solution

For example, if a solution has a 10% concentration of salt in one liter of water, adding another liter of water would halve the concentration of the salt, to 5%. This example can be shown mathematically using the above equation, where:
 * C1 = 10%
 * V1 = 1 L
 * C2 = 5%
 * V2 = 2 L

[math]10\% \times 1 L = 5\% \times 2L[/math]

[math]0.1 \times 1 L = 0.05 \times 2L[/math]

[math]0.1 L = 0.1 L[/math]

Lab Tasks
In addition to completing a written test, Potions and Poisons competitors must complete at least one lab task, according to the trial rules. These lab tasks may include the following:
 * Chromatography
 * Mixture of Reagents
 * Separation of a mixture
 * Serial dilutions
 * Determining pH
 * Conductivity testing
 * Observations from reagent mixing (color change, precipitate formation, etc.)
 * Distinguishing between physical and chemical changes