Chemical Reactions
One of the following is a chemical change, NOT a physical change: splitting wood, melting ice, burning wood or dissolving salt in water.
What is burning wood?
In the formula 5CaSO4, this is the number of oxygen atoms.
What is 20?
A substance that enters a chemical reaction is called this.
What is a reactant?
A reaction that releases thermal energy is called this.
What is exothermic?
This type of change in a substance's appearance is not a chemical change and is usually reversible.
What is a physical change?
AgNO3+NaCl→AgCl+NaNO3 is an example of what type of chemical reaction?
What is double replacement?
This type of change occurs when a substance or multiple substances rearrange and a new substance is created.
What is a chemical change?
A chemical reaction in which thermal energy is absorbed.
What is endothermic?
A molecule consisting of two atoms. Ex: O2 or H2
What is a diatomic molecule?
When balancing an equation this type of number CAN be changed (hint - it's can be seen as a large number at the front of the chemical formula)
What is a coefficient?
Balance the following chemical reaction:
H2 + NaCl --> HCl + Na
H2+ 2NaCl --> 2HCl + 2Na
An expression in which symbols and formulas are used to represent a chemical reaction.
A chemical equation
What is the standard oxidation number for transition metals?
What is 2+?
State the Law of Conservation of Mass.
What is "matter can not be created or destroyed in a chemical reaction"?
When balancing an equation, these numbers can not be changed.
What is a subscript?
A solid that forms from a solution during a chemical reaction.
What is a precipitate?
An increase in temperature will usually cause the rate of reaction to ________________.
What is increase?
2HgO ---> 2Hg + O
is an example of this type of reaction.
What is decomposition?
What type of elements form covalent bonds?
What is a nonmetal and a nonmetal?
Give three examples of a physical sign that a chemical change has taken place.
What is temp. change, color change, odor change, formation of a precipitate, formation of a gas?
What type of chemical reaction is
Mg+ HCL➡️MgCl2 + H2?
What is single replacement?
What do we call a substance added to a chemical reaction to speed up the reaction, that remains "untouched" through the entire process?
What is a catalyst?
Balance the reaction:
Na +H2O -> NaOH + H2
What is 2Na + 2H2O ->2NaOH + H2
This type of reaction has O2 on the reactant side, and usually has CO2 and H2O on the product side.
What is a combustion reaction?