Science 9 Hon. extensions
Project No. 1 - An introduction to Chemistry ...
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Videos that may help ...
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Chemical Equations ... Hon. extensions
The Four Major Types of Reactions ...
Name General Reaction Pattern
1) Combination or synthesis A + B ➔ AB
2) Decomposition AB ➔ A + B
3) Substitution or Single Replacement A + BC ➔ B + AC
4) Metathesis or Double Replacement/Displacement AB + CD ➔ AD + CB
Then we add on ....
5) Acid Base Neutralization HX + MOH ➔ MX + H2O
Acid (H) + Base (OH) ➔ Salt + Water
6) Combustion CXCY + O2 ➔ CO2 + H2O
hydrocarbon + oxygen ➔ carbon dioxide + water
Name General Reaction Pattern
1) Combination or synthesis A + B ➔ AB
2) Decomposition AB ➔ A + B
3) Substitution or Single Replacement A + BC ➔ B + AC
4) Metathesis or Double Replacement/Displacement AB + CD ➔ AD + CB
Then we add on ....
5) Acid Base Neutralization HX + MOH ➔ MX + H2O
Acid (H) + Base (OH) ➔ Salt + Water
6) Combustion CXCY + O2 ➔ CO2 + H2O
hydrocarbon + oxygen ➔ carbon dioxide + water
Balancing Combustion Reactions
As you have learned, there is not always a straightforward way to balance a reaction. We tend to just go back and forth, balancing elements on the left and the right, until it works. Combustion reactions are easier!
Balance the elements in the following order: carbon, hydrogen then oxygen.
Take pentane:
C5H12 + O2 -> CO2 + H2O
Step 1 balance carbon: you see 5 carbons on the left so you know it will produce 5 CO2.
C5H12 + O2 -> 5 CO2 + H2O
Step 2 balance hydrogen: you see 12 hydrogens on the left so you know it will produce 6 H2O.
C5H12 + O2 -> 5 CO2 + 6 H2O
Step 3 balance oxygen: you see 10+6 or 16 oxygens on the right so you know it will require 8 O2.
C5H12 + 8 O2 -> 5 CO2 + 6 H2O
And it is balanced!
As you have learned, there is not always a straightforward way to balance a reaction. We tend to just go back and forth, balancing elements on the left and the right, until it works. Combustion reactions are easier!
Balance the elements in the following order: carbon, hydrogen then oxygen.
Take pentane:
C5H12 + O2 -> CO2 + H2O
Step 1 balance carbon: you see 5 carbons on the left so you know it will produce 5 CO2.
C5H12 + O2 -> 5 CO2 + H2O
Step 2 balance hydrogen: you see 12 hydrogens on the left so you know it will produce 6 H2O.
C5H12 + O2 -> 5 CO2 + 6 H2O
Step 3 balance oxygen: you see 10+6 or 16 oxygens on the right so you know it will require 8 O2.
C5H12 + 8 O2 -> 5 CO2 + 6 H2O
And it is balanced!
Acids and bases
Firstly - you WILL need the periodic table from here.
Many common pure substances can be classified according to whether they are acids or bases. Some acids and bases are corrosive and poisonous, whereas others add flavour to food or are vitamins.
Acid-base indicators are chemicals that change colour in response to acidic or basic conditions. The pH scale is a number scale for
measuring how acidic or basic a solution is.
A pH value below pH 7 is acidic, pH 7 is neutral, and a pH value above pH 7 is basic.
Generally, the chemical formula for an acid starts with H (hydrogen) on the left of the formula. Bases generally have OH on the right of their chemical formulas.
So, if you add an acid and a base together you will neutralize them and get a water and a salt. That makes sense because it looks like a double replacement reaction. Ex HCl + NaOH -> HOH or simply water (H2O) and NaCl.
Firstly - you WILL need the periodic table from here.
Many common pure substances can be classified according to whether they are acids or bases. Some acids and bases are corrosive and poisonous, whereas others add flavour to food or are vitamins.
Acid-base indicators are chemicals that change colour in response to acidic or basic conditions. The pH scale is a number scale for
measuring how acidic or basic a solution is.
A pH value below pH 7 is acidic, pH 7 is neutral, and a pH value above pH 7 is basic.
Generally, the chemical formula for an acid starts with H (hydrogen) on the left of the formula. Bases generally have OH on the right of their chemical formulas.
So, if you add an acid and a base together you will neutralize them and get a water and a salt. That makes sense because it looks like a double replacement reaction. Ex HCl + NaOH -> HOH or simply water (H2O) and NaCl.
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What are acids and bases?
Many common pure substances can be classified according to whether they are acids or bases. Acids produce hydrogen ions (H+) and bases produce hydroxide ions (OH–) when dissolved in solution. The concentration of hydrogen ions refers to the number of hydrogen ions in a specific volume of solution. Solutions with a high concentration of hydrogen ions are highly acidic. Similarly, solutions with a high concentration of hydroxide ions are highly basic. When an acidic solution is mixed with a basic solution, the solutions can neutralize each other, which means that the acidic and basic properties are in balance.
What is pH?
Testing the pH of a solution is a way of measuring its concentration of hydrogen ions, H+(aq). The pH scale is a number scale that indicates how acidic or basic a solution is. Acids have a pH below 7 and bases have a pH above 7. Neutral solutions have a pH of 7. On the pH scale, one unit of change represents a 10-fold change in the degree of acidity or basicity. For example, a two-unit drop in pH is a 102 or 100 times increase in acidity.
What are pH indicators?
pH indicators are chemicals that change colour depending on the pH of a solution.
Litmus paper can determine whether a solution is acidic or basic. Blue litmus paper turns red in an acidic solution (below pH 7). Red litmus paper changes to blue in a basic solution (above pH 7),
A universal indicator contains a number of indicators that turn different colours depending on the pH of the solution.
Phenolphthalein, bromothymol blue, indigo carmine, methyl orange, and methyl red are other common pH indicators. Each determines pH within a different range.
How are acids and bases named?
Acids: Generally, the chemical formula for an acid starts with an H (hydrogen) on the left-hand side of the formula – that can make them easy to spot.
They are easier to name than you would think.
1 – identify the compound as an acid (starts with the H), then we apply one of three scenarios.
Thats it ... easy right?
Many common pure substances can be classified according to whether they are acids or bases. Acids produce hydrogen ions (H+) and bases produce hydroxide ions (OH–) when dissolved in solution. The concentration of hydrogen ions refers to the number of hydrogen ions in a specific volume of solution. Solutions with a high concentration of hydrogen ions are highly acidic. Similarly, solutions with a high concentration of hydroxide ions are highly basic. When an acidic solution is mixed with a basic solution, the solutions can neutralize each other, which means that the acidic and basic properties are in balance.
What is pH?
Testing the pH of a solution is a way of measuring its concentration of hydrogen ions, H+(aq). The pH scale is a number scale that indicates how acidic or basic a solution is. Acids have a pH below 7 and bases have a pH above 7. Neutral solutions have a pH of 7. On the pH scale, one unit of change represents a 10-fold change in the degree of acidity or basicity. For example, a two-unit drop in pH is a 102 or 100 times increase in acidity.
What are pH indicators?
pH indicators are chemicals that change colour depending on the pH of a solution.
Litmus paper can determine whether a solution is acidic or basic. Blue litmus paper turns red in an acidic solution (below pH 7). Red litmus paper changes to blue in a basic solution (above pH 7),
A universal indicator contains a number of indicators that turn different colours depending on the pH of the solution.
Phenolphthalein, bromothymol blue, indigo carmine, methyl orange, and methyl red are other common pH indicators. Each determines pH within a different range.
How are acids and bases named?
Acids: Generally, the chemical formula for an acid starts with an H (hydrogen) on the left-hand side of the formula – that can make them easy to spot.
They are easier to name than you would think.
1 – identify the compound as an acid (starts with the H), then we apply one of three scenarios.
- If the right side of the compound is an atom say Cl, then rather than ending the compund in ‘ide’ we turn it into ‘ic’ and lead the name with HYDRO Ex. HCL is Hydrochloric acid
- If the right side is a polyatomic ion that ends in ATE we DON’T USE hydro and again turn the end into ‘ic’. Ex. H2CO3 is made of hydrogen and carbonate, so it becomes carbonic acid.
- If it a polyatomic that ends in something else you end it with ‘OUS’. Ex H2SO3 you have hydrogen and sulfite, so it becomes sulphurous acid.
Thats it ... easy right?