Chapter 6/7 Review [Acids and Bases] - Science Flashcards
Chemical Reaction
A process in which substances interact, causing the formation of new substances with new properties
Word Equation
A way of describing a chemical reaction using the names of the reactants and products
Chemical Equation
A way of describing a chemical reaction using the chemical formulas of the reactants and products
Reactants
Substances that are used up during the reaction [left of the arrow]
Products
Substances that are produced during the reaction [right of the arrow]
Symbols in the Equations
Arrow: Shows direction chemical reaction is going
+: Placed between multiple reactants and products
Law of Conservation of Mass
- In any given chemical reaction, the total mass of reactants equals the total mass of the products
- Matter is neither created or destroyed
- The products of a chemical reaction have the same mass as the reactants
How to solve missing mass
- Write out the word/chemical equation
- Place all the known masses under the reactants and product and place an “x” under the missing mass
- Solve for missing mass
- Write a summary statement
How to balance a Chemical Equation
- Write word the word equation
- Write the skeleton equation
- Count the atoms of each element on each side of the arrow
- Multiply the formulas by an appropriate coefficient until all atoms are balance
Skeleton Equation
Original/unbalanced equation
Synthesis Reaction
X + Y → XY
Combine atoms and/or compounds into larger compounds
2 or more reactants, only 1 product
Decomposition Reaction
XY → X + Y
Opposite of Synthesis: Compounds breakdown into elements or smaller compounds
Single Displacement
Metal: X + YZ → Y + XZ
Non Metal: A2 + YB → B2 + YA
One element displaces/replaces another in a compound
1) A metal [cation] can displace another metal [cation] or hydrogen
2) A nonmetal [anion] displaces another nonmetal [anion]
Double Displacement
WX + YZ → WZ + YX
Elements [or polyatomic ions] in different compounds “displace” each other by changing places
Combustion
C3H8 + 5O2 → 3CO2 + 4H2O + Energy
The rapid reaction of a substance with oxygen to produce compounds called oxides. Energy is also produced
Corrosion
The breakdown of a metal as a result of chemical reactions with its environment
Rusting
Occurs when a metal, containing Iron is exposed to air, water, electrolytes, acidity or mechanical stress leading to corrosion
Property of Acids
Conductors
Reacts with Mg
Reacts with Sodium Hydrogen Carbonate
Bromothymol Blue Indicator - Yellow
Red Litmus Paper - Red
Blue Litmus Paper - Blue
Property of Bases
Conductors
No reaction with Mg
No reaction with Sodium Hydrogen Carbonate
Bromothymol Blue Indicator - Blue
Red Litmus Paper - Blue
Blue Litmus Paper - Red
Binary Acids
Hydrogen + Non-Metal
Oxyacids
Hydrogen + Polyatomic Ions
Chemical Formula of Bases
Hydroxide + Carbonate Ions
Difference between Liquid and Aqueous
Liquid is a state of matter whereas Aqueous is a solution [dissolved in water]
What is pH
A measure of how acidic or basic a solution is
What is the pH scale
A numerical scale ranging from zero to fourteen that is used to compare the acidity of solutions
pH levels [acid, base, neutral]
Less than 7 - Acidic
Greater than 7 - Basic
7 - Neutral
What determines the pH level of soil
- Types of rocks in the area
- The kinds of plants growing
- The materials people have added [intentional or not]
What pH do legumes grow best in
Slightly basic soil [5-6]
What pH does corn grow best in
Mildly acidic soil [Below 5]
How to increase/decrease soil pH
Decrease: Compost or Aluminum Sulfate
Increase: Calcium Oxide
What metals is some Canadian soil intoxicated with
Cadmium and Lead
Acid Leaching
Removes heavy metals by adding an acid solution and ‘catching’ the solution that drains through [Invasive and expensive]
Phytoremediation
[Some plants can absorb metals from the soil as they grow] Harvesting plants that have absorbed the metals and burning them, then recycling the metals from the ashes
pH of skincare
Close to neutral
Cleaning products and pH
Acidic making them very corrosive, damaging to eyes and skin but helpful when it comes to cleaning
- They’re labeled with symbols to indict their potential danger
What should the pH of a swimming pool be
7.2 - 7.8
Below 7 irritates eyes
Above 8 irritates eyes, makes cloudy water and chlorine becomes less effective
How to adjust pool pH
pH is too high - hydrochloric [muriatic] acid
pH is too low - Sodium carbonate
What is a neutralization reaction
A double displacement reaction in which an acid and base react to form an ionic compound [salt] and water
What is an Acid
pH less than 7 and produces hydrogen atoms in a solution
What is a Base
pH greater than 7 and produces hydroxide ions in a solution
