Chemical Reactions
Where are the reactants of chemical equation located?
They are always located on the left side of the equation.
The starting substances of a chemical equation.
Reactants
Balance the following equation: _____H2 + ____O2 ---> ____H2O
2 H2 + 1O2 ---> 2H2O
How many atoms of each element are in this compound: MgCl2
There are 1Mg and 2Cl
Physical or chemical change? Breaking an egg.
Physical change
Where are the products of a chemical equation located?
They are always located on the right side of the equation.
The substances formed during the reaction.
Products
Balance the following Equation: _____KClO3 ---> KCl + ______O2
2KClO3 ---> 2KCl + 3O2
How many atoms of each element are in this compound: NH4Cl
There are 1N, 4H and 1Cl
What do the following symbols represent in a chemical equation: (s), (l), (g)
(s)- indicates a substance in a solid state.
(l)- indicates a substance in a liquid state.
(g)- indicates a substance in a gas state.
Identify the reactants and products in the following chemical equation: H2 + NaCl ---> H2Na + Cl + S
Reactants: H, Na, Cl Products: H, Na, Cl, S
The small numbers directly to the right of the elemental symbol.
Subscripts
Balance the following equation: ____C3H8 + _____O2 ---> ____CO2 + ____H2O
1C3H8 + 5O2 ---> 3CO2 + 4H2O
How many atoms of each element are in this compound: 4HNO3
There are 4H, 4N, and 12 O
What are coefficients used for?
They are used to balance chemical equations.
What does the law of conservation of mass state?
The law of conservation of mass states that matter durning a chemical change can neither be created nor destroyed.
The big numbers written in front of each compound.
Balance the following equation: ____P + _____O2 --->_____P2O5
4P + 5O2 ---> 2P2O5
How many atoms of each element are in this compound: 2CH3OH
There are 2C, 8H, 2 O
Chemical or physical change? Baking soda added to vinegar, resulting in the formation of carbon dioxide gas.
Chemical change
What do subscripts indicate? Also, how many atoms in the reactant side does each element have in the following chemical equation: NaOH + H2CO3 ---> Na2CO3 + H2O
Subscripts indicate the number of each type of atom that make up a particular compound. In the reactant side there are: 1Na, 4O, 3H, 1C
A process in which atoms of one or more substances are rearranged in order to form new substances.
Chemical reaction
Balance the following equation: ___NaBr + ____CaF2 ---> ____NaF + ____CaBr2
2NaBr + 1CaF2 ---> 2NaF + 1CaBr2
How many atoms of each element are in this compound: 2H3NCH3Br
There are 12H, 2N, 2C, and 2Br
What are open and closed systems?
An open system allows matter (stuff) to enter and leave the system. A closed system does not allow matter to enter or leave.