GR 11 Unit 2 test

Simple substances combine to form more complex compounds Product can either be ionic or molecular X + Y = XY Element + element = compound Compound + element = complex compound Compound + Compound = very complex compound Ex. 2Na + Cl2 —> 2NaCl

COMBUSTION – means burning with oxygen METAL + OXYGEN —> METAL OXIDE: 2Mg + O2 (g) —> 2MgO Note: Metal oxide in water —> BASE MgO + H2O 🡪 Mg (OH)2 NON-METAL + OXYGEN —> NON- METAL OXIDE: 2S + 3O2 —> 2SO3 Note: non-metal oxide + water —> ACID: SO3 + H2O —> H2SO4 (aq)

A compound is broken down into simpler substances XY —> X + Y Can be broken in to elements or compounds Often requires energy. i.e. Heat e.g. 2HCl —> H2(g) + Cl2 (g)

Metal CARBONATES decompose to produce the metal oxide and carbon dioxide gas. Example: MgCO3 (aq) —> MgO(s) + CO2 (g) And Carbonic acid decomposing to produce water and carbon dioxide: H2CO3(aq) → H2O(l) + CO2(g)

An element reacts with a compound and displaces a second element from the compound to form an element and a new compound General form: A + BC —> AC + B *Don’t forget to follow the activity series. Some reactions will not occur. If A is more reactive than B (i.e. A»B), the reaction will proceed.

AB + CD —> AD + CB There are usually 2 types of these reactions : Precipitation reactions - formation of an insoluble compound called a precipitate eg: AgNO3(aq) + NaCl(aq) —> NaNo3(aq) + AgCl(s) Neutralization reactions – formation of water and a salt eg: HCl(aq) + NaOH(aq) 🡪 H2O(l) + NaCl(aq) *Note: The valence of multivalent elements stays the same on both sides of the equation

A hydrocarbon is a molecular compound containing only carbon, hydrogen and sometimes oxygen. Complete combustion of a hydrocarbon always produces only 2 products: CO2 and H2O Example: Write a balanced chemical equation for the combustion of propane (C3H8). C3H8 + 5O2 —> 3CO2 + 4H2O

Exothermic reaction - a chemical reaction that gives out heat to the surroundings. e.g wood burning Endothermic reaction - a chemical reaction that absorbs heat from the surroundings e.g boiling an egg

A neutralization reaction is a double displacement reaction that occurs when: An acid combines with a base ● The general equation for a neutralization reaction is: ● Acid + base → salt (ionic compound) + water ● H(non-metal) + (metal)OH → (metal)(nonmetal) + HOH Uses: The neutralisation reaction is used to control the pH of the soil. Useful in reversing the damage caused by acid rain on lakes/waterways.

The reactions between an acid and a metal carbonate or a metal hydrogen carbonate are double displacement reactions that produce carbonic acid. The carbonic acid is unstable. It rapidly decomposes into water and carbon dioxide. 2HCl(aq) + Na₂CO₃(aq) → H₂CO₃(aq) + 2NaCl(aq) And shortly after H₂CO₃(aq) → H₂O(l) + CO₂(g) Can be written as one reaction: 2HCl(aq) + Na₂CO₃(aq) → H₂O(l) + CO₂(g) + 2NaCl(aq)

Baking soda and baking powder are both leavening agents. (make dough rise) The leavening action of baking soda is activated when it is mixed with an acidic ingredient like fruit juice, vinegar, or buttermilk. The chemical equation for the reaction of the citric acid, H3C6H5O7(aq) , in fruit juice with baking soda is H3C6H5O7(aq) + 3NaHCO3(s) → Na3C6H5O7(aq) + 3H2O(l) + 3CO2(g) The 3CO2(g) released from the reaction is the reason the dough rises.

Electron configurations (Energy levels) Atomic size (radius) Ionization energies

• Ions with large charges (eg. PO43-) tend to be less soluble. Reason: Increasing the charge increases the force that holds ions together • Smaller ions (ie. those with a smaller radius) tend to be less soluble. Reason: Small ions bond more closely together and thus the bond between them is stronger.

Solutes “dissociate” into their ions when dissolved in solution. Therefore, the reaction really looks like: All of the ions, and the precipitate 2Na+(aq) + S2-(aq) + Fe2+(aq) + SO42-(aq) —> 2Na+(aq) + SO42-(aq) + FeS(s)

Ions which appear on both sides of the equation in effect cancel each other out. Therefore: 2Na+(aq) + S2-(aq) + Fe2+(aq) + SO42-(aq) —-> 2Na+(aq) + SO42-(aq) + FeS(s) Would turn into: S2-(aq) + Fe2+(aq) 🡪 FeS(s)

Spectator Ions are those ions not directly involved in the net reaction (ie. they cancel out). On both sides in the same amount in the same state

Physical Properties: Clear, colourless gas at room temperature Chemical Properties: Supports combustion Test: Glowing splint Results: Burst into flames

Physical Properties: Clear, colourless gas at room temperature. It is less dense than air. Chemical Properties: Reacts explosively Test: Flaming splint Results: Squeaky pop

Physical Properties: Clear, colourless gas at room temperature. It is more dense than air. Chemical Properties: Does not burn, but puts out flame. Test: Flaming Splint Results: Flame goes out

Physical Properties: Clear, colourless gas at higher temperatures Chemical Properties: Does not burn. Test: cobalt chloride paper. Results: Turns from blue to pink when wet

It goes fluorine is the most reactive than in order from top to bottom