Science Chemistry Unit Test Flashcards
What are ionic compounds usually made of?
A metal and a non metal
What is an anion?
an atom or element with a negative charge (more electrons then protons)
What is a cation?
an atom or element with a positive charge (more protons then electrons)
What are some properties of ionic compounds
- When soluble they are able to conduct electricity
- They are packed highly in an ordered arrangement (pattern called a crystal lattice)
- Hard
- Brittle
High melting/boiling points
What are the two types of ionic compounds
Binary: 2 elements
Polyatomic: Metal + Ion made of more then 2 elements
What is a multivalent metal?
A metal with more then one ionic charge
What is a binary acid?
certain molecular compounds where hydrogen is combined with a second non-metal
What is an oxyacid?
An acid that contains an oxygen atom bonded to a hydrogen atom and at least other element
What is a polyatomic ion?
groups of atoms that tend to stay together and carry an overall ionic charge, these consist of more than one atom
What creates an oxyacid
If a polyatomic ion bonds with hydrogen instead of a metal
What is a molecular bond?
- A compounds formed when atoms of two or more elements SHARE electrons,
- Usually with 2 or more non-metals
What is a diatomic element?
An element that exists naturally as two of the same element bonded together
What are the diatomic elements
H O F Br I N Cl
Hydrogen, Oxygen, Bromine, Iodine, Nitrogen, Chlorine
What is a chemical reaction?
One or more substances change into different substances
What is a reactant?
The substances that are used up during the reaction, they are the beginning stage (reactants > products)
What is a product?
The substances that are produced during the reaction, the second stage (reactants > products)
What is a word equation and an example
- A way of describing a chemical reaction using the names of the reactants and products
- Iron + oxide > Iron(||) Oxide
What is a chemical equation and an example
- A way of describing a chemical reaction using the chemical formulas of the reactants and products
- Fe + S > FeS
What does the arrow represent?
It indicates the direction in which the chemical reaction is going
What are words that mean arrow
- Yields
- Forms
- Produces
- Creates
- Becomes
What does the plus sign mean
- Shows that the two elements are being added together to create the reaction
- Indicates the reactants must be in contact with each other
What are words that indicate +
- Plus
- Add
- Combine
- And
- Form
What is a state symbol
A symbol indicating the physical state of the chemical at room temperature
What are the 4 state symbols
(s) - Solid
(l) - Liquid
(g) - Gas
(aq) - Aqueous, meaning dissolved in water
What is the law of the conservation of mass
the total mass of the reactants = total mass of the products
what is a balanced chemical equation?
An equation where the reactants and the products contain equal numbers of atoms of each type
What are coefficients and what do they apply to
- A number written in front of a chemical symbol or formula which indicates the number of atoms or molecules of that substance
- A coefficient is multiplied to all of the elements infant of it (the line stops when there is a + or an >)
What is a solution
a mixture of two or more substances
What is a synthesis reaction and what is the equation?
- A reaction where two reactions combine to make a larger or more complex product
- A + B > AB
What is a decomposition reaction?
- A reaction in which a large or more complex molecule breaks down to form two (or more) simpler products
- AB > A + B
What is a single displacement reaction and what is the general formula?
- A reaction in which an element displaces another element in a compound, producing a new compound and a new element
- A + BC > AC + B
What is a double displacement reaction and what is the general formula?
- A reaction that occurs when elements in different compounds displace each other or exchange places, producing TWO new compounds
- AB + CD > AD + CB
In single and double displacement, what type of chemical/molecule/element usually switches?
- The front element usually switches with the other front, or singular element
- The metals switch
What always switches in a single displacement reaction with a ionic compounds and a metal?
The positive cation is replaced with each other, they switch
Single displacement reactions often occur in… and …
- Aqueous solution
- When metals are placed into acids
Many double displacement reactions occur between…
Two ionic compounds
How do precipitates form?
- some ionic compounds don’t dissolve in water
- When these compounds form during a reaction they become visible as a percipitate
Double displacement reactions often result in…
the formation of a precipitate
What is an acid?
An aqueous solution that conducts electricity, tastes sour, turns blue litmus red and neutralizes bases
What are some properties of acids?
- Sour tasting
- Water soluble
- Reacts with metals and carbonates
- Acid solutions conduct electricity
- When acids are dissolved in water they produce Hydrogen Ions
- Turn blue litmus red
- neutralize bases
How are acids involved In the food industry, what are some examples of acids
- acids can act as a preservative as some harmful organism cannot survive in acid
- acids like vinegar are in a lot of foods and that why things like ketchup and pickles have long shelf lives, because they contain lots of vinegar
- ex lemon juice, vinegar apples
Reaction with metals acid
Acids typically react with metals to produce hydrogen
Reaction with carbonatyes acids and example
- Acids react with carbonates to produce bubbles of CO2 gas
- ex vinegar and baking soda to unblock a sink
Electrical conductivity acids
- solutions can conduct electricity only if it constraints ions, acids do not contain ions since they are molecular compounds
- collisions with water molecules break acid molecules apart to create cations (hydrogen ions) and anions
The acid shows its properties only when its…
dissolved in water
What are some things to look out for when identifying Binary Acids?
- Contains two elements
- No Oxygen atom
- Hydro is infant of it
- aq symbol next to it
- IC as the ending
What are some things to look out for when identyfying Oxy Acids
- IC as the ending
- Related to polyatomic ions
Relation of oxyacids to polyatomic ions
the formula for oxyacids are very similar, and they only differ from the one or more hydrogen atoms that are placed in the begging (to make it an acid, ie H2CO3 vs CO3)
What is a base
An aqueous solution that conducts electricity and turn red litmus blue
What are the properties of a base?
- Bitter tasting
- Water soluble
- Feels slippery when dissolved in water
- Good conductors of electricity
- Change the colour of acid-base indicators
Why are bases good conductors of electricity
Bc they release hydroxide ions when dissolved in water
Bases are also described as…
Alkaline
What do bases do
Read with proteins to break them down into smaller molecules
Electric conductivity in a base
- bases are electrolytes meaning solutions are good conductors of electricity
Common bases are usually…
Ionic compounds
What is an acid base indicator?
A substance that changes colour depending on whether something is an acid or a base
- it has a different colour depending on the acidity or basicity of a solution
If a solution has a pH of 13 is it highly acidic, slightly acidic, neutral, slightly basic, or highly basic
highly basic
If a solution has a pH of 6 is it highly acidic, slightly acidic, neutral, slightly basic, or highly basic
slightly acidic
If a solution has a pH of 1 is it highly acidic, slightly acidic, neutral, slightly basic, or highly basic
highly acidic
If a solution has a pH of 5 is it highly acidic, slightly acidic, neutral, slightly basic, or highly basic
slightly acidic
What is the colour of Bromothymol blue in an acid and a base?
acid: yellow
base: blue
What is the colour of Phenolphthalein in an acid and a base?
acid: Colourless
base: Pink
What is the colour of phenol red in an acid and a base?
acid:yellow
base:red/pink
What is the colour of Red Litmus in an acid and a base?
acid: Red
base: Blue
What is the colour of Blue Litmus in an acid and a base?
acid: Red
base: Blue
What is the colour of methyl orange in an acid and a base?
acid: Red
base: Orange/Yellow
What are some identifications if something is an acid vs base?
- most bases are ionic compounds containing hydroxide and carbonate
- OH is in the chemical formula
- Has a positive ion, (usually a metal) and a nonmetal or a polyatomic ion
What is pH
A measure of how acidic or basic a solution is
If the solution has a pH of 7 or near 7 it is …
Neutral
If the solution has a pH of 7.1 + it is…
basic
If the solution has a pH of 6.9 and under it is…
acidic
What is the pH scale
A numerical scale ranging from zero to 14 that is used to compare acidity of solutions
Neutral:
Neither acidic or basic, with a pH of 7
What determines the solutions pH
- The concentration of hydrogen ions
- The greater concentration, the more acidic
Very high and very low pH scale are
- corrosive and dangerous
What is concentration
A measure of quantity of a substance dissolved in a given volume of a solution
What is acid leaching
the process of removing heavy metals from contaminated soils by adding an acid solution to the soil an catching the solution that drains through
What is a neutralization reaction and how does it occur
- a chemical reaction in which an acid and a base react to form an ionic compound ( a salt) and water
- pH closer to 7
- Usually called salt and water
Neutralization reactions are…
what is a general formula for them
- double displacement reactions
- acid + base > water + ionic compound
