(Chapter 3.1) Chemical Reactions: Changing Matter Flashcards
Define compounds
A substance that consists of at least 2 elements.
Define reactants
A substance that occurs initially in a chemical reaction.
Define product
A substance that is formed as a result of the chemical reaction
What happens to the atoms in a chemical reaction?
The atoms are rearranged, not created or destroyed
Signs of a chemical reaction
Colour change, temperature change, precipitate, production of a gas, smell or taste change and light emission
In chemistry, which bond (ionic or covalent) is stronger?
Ionic. If you were interested, the “in chemistry” part is necessary as in biology, covalent are considered to be stronger as the 2 subjects measure strength in different ways. Chemistry measures absolute strength while biology measures the strength in a biological system, which is usually aqueous (water-based) and ionic bonds break easier in water.
Ionic compounds are bonds between…
Metal and non-metal elements
How are ionic compounds formed?
An electron from the valence shell of a metallic element is permanently transferred to the valence shell of a non-metallic element
Covalent bonds are bonds between…
Non-metallic elements
How are covalent compounds formed?
Non-metallic elements share valence electrons in order to be stable
What is the difference between covalent and molecular compounds
There is no difference
When naming compounds, which element is in front?
The element found further left in the periodic table is in front
When is the ‘-ate’ and ‘-ite’ ending used? E.g. Nitrate and Nitrite
The ‘ate’ ending is used for polyatomic anions with the higher oxidation state. The ‘-ite’ ending is used for polyatomic anions with the lower oxidation state. This can be shown through nitrate (NO3) and nitrite (NO2). An exception to this rule is hydroxide as when it was first discovered, it was believed to be a monoatomic anion.
When is the ‘ide’ ending used? E.g. Chloride
The ‘ide’ ending is used for monatomic ions
Define cation
An positive ion
Define anion
A negative ion
Is the prefix ‘mono-‘ used for cations
No
What is a binary compound?
A compound with 2 different elements
What is a non-binary compound?
A compounds with at 3 different elements
When is prefixes of both elements in a compound dropped?
In a binary ionic compound
How can chemical reactions be expressed?
Chemical and word equations
What does the Law of Conservation of Mass state?
In a closed system, the mass of the system must remain constant as mass is not created or destroyed
Define precipitate
An insoluble salt (solid)
Express the difference between ammonium and ammonia by stating the chemical formula.
Ammonium is NH4 while ammonia is NH3
What does the symbol (s) mean in a chemical reaction?
It signifies that the substance is a solid
What does the symbol (l) mean in a chemical reaction?
It signifies that the substance is a liquid
What does the symbol (g) mean in a chemical reaction?
It signifies that the substance is a gas
What does the symbol (aq) mean in a chemical reaction?
It signifies that the substance is in water
Define solvent
A medium that dissolves a solute
Define solute
A substance that dissolves in the solvent
Contrast chemical change with physical change
In a chemical change, at least 1 new substance is formed through the breakage or formation of bonds. On the other hand, in a physical change, the state of matter changes but the chemical bonds are untouched
