Chemical Reactions
What is a chemical reaction?
the process in which atoms of one or more substances are rearranged to form different substances
What is a chemical equation?
The representation of a chemical reaction using words or chemical formulas.
reactant A + reactant B --> product C + product D
What is the Law of Conservation of mass?
In a chemical reaction, the total mass of the substances used is equal to the total mass of the substances produced. Mass is neither created nor destroyed in chemical reactions.
What is the atomic number for sulphur?
16
A + B --> AB
yes. Two or more reactants combine to form a single product.
What is an ionic compound?
a compound made of oppositely charged ions. Metal + Non-Metal
What are the reactants in the chemical equation:
Na+ + Cl- --> NaCl
Na (sodium) and Cl (chloride)
What is an exothermic reaction? Provide an example.
A chemical reaction in which there is net energy release to the surroundings.
Ex. making an ice cube, iron rusting, clouds making snowflakes, burning sugar
What group number is Calcium in?
period 2
What is an example of a decomposition reaction?
-A chemical reaction in which a compound is broken down into elements or simpler compounds
What is a covalent compound?
A compound that results when atoms of two or more atoms bond covalently. Non-metal + Non-metal
Mg + O2 --> MgO
MgO - Magnesium Oxide
What is an endothermic reaction? Provide an example.
A chemical reaction in which there is net absorption of energy from the surroundings.
Ex. ice melting, water evaporating, cooking an egg
What is the name of the ionic compound KBr?
Potassium Bromide
Provide the formula for a single replacement reaction.
A + BX --> AX + B (metal replaces another metal)
or
AX + Y --> AY + X (non-metal replaces another non-metal)
Where are the non-metals found on the periodic table?
to the left of the staircase
What is a coefficient?
the number placed in front of a chemical formula in a balanced chemical equation to show the ratios of substances in a reaction.
Ex. 2Mg - means there are 2 magnesium atoms
Does the temperature increase or decrease in an endothermic reaction?
decrease
What is the name of the covalent compound SiO2?
Silicon Dioxide
What type of compounds are formed in double replacement reactions? Ionic or covalent?
Ionic compounds. Two ionic compounds react to produce two new compounds.
AX + BY --> AY + BX
Is water (H20) an ionic or covalent compound?
covalent. Hydrogen and Oxygen are both non-metals
Is CaF an example of a molecule?
No. Molecules are covalent compounds (non-metal + non-metal)
Is combustion an example of an endothermic or exothermic reaction?
exothermic. It produces heat.
What is the ionic charge of fluorine?
-2. It gains two electrons to become stable.
What two reactants do you need in a neutralization reaction? What is formed?
An acid and a base combine to form a salt and water
Acid + Base --> Salt + Water