Chemical Reactions

Why do equations have to be balanced?

Conservation of mass, needs to be equal

Difference between a subscript and a coefficient? Which can be changed?

Subscript makes up the element, coefficient changes how many. Only coefficient can be changed

What does diatomic mean?

Made of two atoms to remain stable

Which seven elements are diatomic?

H, N, O, F, Cl, Br, I

What is the difference between a word equation and a balanced equation?

Word doesn’t tell you the amounts of elements in it, only the base

How can you determine if an element can replace the other in a single replacement reaction?

Single element has to be higher on the chart

Explain different symbols

Triangle: heat Degree: must be that temp Pressure: must be at that pressure Chemical: required a catalyst to speed up

How water ionizes ionic compounds

Water pulls apart the compound and dissolves it

Electrolytes

Substances that ionize in water

Strong electrolytes

100% ionize

Weak electrolytes

Only partially ionize (less than 10%)

Non-electrolytes

Do not ionize, molecules stay intact

Soluble or insoluble (What and how is it determined)

Dissolves or doesn’t, use solubility chart

Combustion reaction

Rapid chemical reaction, contains CO2 and H2O

Double replacement reaction

Parts of two compounds switch places AB+CD=AD+CB

Single replacement reaction

A single uncombined element replaces another in the compound AB+C=A+CB

Synthesis reaction

2 or more substances combine to make one complex substance

Decomposition reaction

A more complex substance breaks down into simple parts