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 H&#8322; and O&#8322;. 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)