NCEA chemistry level one.docx

**These are some of my notes that I have created by reading an NCEA textbook about NCEA level 1 chemistry.** **This non official resource has a lot of Ethan jokes, so please beware and do not let him see this.** **You are free to use this anytime.\ I have written separate documents for biology and...

**These are some of my notes that I have created by reading an NCEA textbook about NCEA level 1 chemistry.** **This non official resource has a lot of Ethan jokes, so please beware and do not let him see this.** **You are free to use this anytime.\ I have written separate documents for biology and your physics.** **[[https://docs.google.com/document/d/1OordBUZfxcqR6TaS\_mTl9mmKF\_qSiPwNWEUifgWtTqQ/edit?usp=sharing]](https://docs.google.com/document/d/1OordBUZfxcqR6TaS_mTl9mmKF_qSiPwNWEUifgWtTqQ/edit?usp=sharing) - Math** **No link for physics yet.** **Ions** Ions are when 2 or more atoms share electrons and share a stable connection with each other. Ions are usually formed between nonmetals and metals (eg. NaCl - Na or sodium is a metal while chlorine isn\'t)\ \ Atoms that lose an electron have a positive charge, and vice versa. Polyatomic ions are when at least 2 atoms are involved. Eg. Nitrate or NO2\^-1 **Chemical reactions** Before chemical equations, there are 3 things that are important.\ \ Water (Used as an example) is in 3 forms. Solid (Ice), Liquid (Water) and Gas (Steam).\ In order to differentiate between the 3, you can use: H2o (s) For ice/solid H2o (L) for Liquid/ Cold water H2o (g) for gas/steam When a substance is dissolved in water, that liquid is known as a solute/aqueous solution. NaCl (aq) - NaCl or table salt dissolved in water. Chemical equations are in the form, Original substance/solution ---\> Substance/Solution after the reaction "A chemical equation is balanced" means that there are an equal number of the separate types of atoms on each side. For example, CaCO3 ---\> CaO + CO2 Left side \| Right side Ca 1 \| 1 C 1 \| 1 O 3 \| 1+2=3 Therefore, this chemical equation is balanced. What happens when the chemical equation isn't? H2O2 ---\> O2 + H2O (L) Left side \| Right side H 2 \| 2 O 2 \| 1+2=3 To balance this equation, you must put a coefficient on one of the elements. This applies to both sides. (If you put hydrogen on one side you must with the other) 2HO2 ---\> O2+ 2H2O (L) Left side \| Right side H 2x2=4 \| 2x2=4 O 2x2=4 \| (1x2)+2=4\ \ Therefore everything is balanced. Chemical equations take trial and error, so please do not give up. **Metals, non metals and their properties and reactions** Metals and its properties - - - - - **Alloys** An alloy is a metal where a metal is mixed with another substance chemically. This is due to the fact some metals (such as copper) are too soft to be used for different purposes, such as building. Alloys are usually metal added to another metal. - - - Activity series - Sodium - Lithium - Calcium - Magnesium - Aluminium - Zinc - Iron - Lead - (Hydrogen) - Copper - Silver - Gold Most ---\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--\> Least **Metals reaction with oxygen** Metal + Oxygen (o2) ----\> Metal **oxide** Sodium, lithium, calcium and magnesium and aluminium (Aluminium is a bit slower) They react rapidly and aggressively with oxygen. 2mg + O2 = 2mgo Lead and copper react very slowly (Oxidized) 2cu + O2 = 2cuO Gold and silver do not oxidise in any circumstance. **Metals reaction with water** Metal + H20 (L) ---\> Metal hydroxide + Hydrogen gas Sodium, lithium, calcium and potassium react vigorously with steam. 2Li + 2h2o ---\> Li2OH+H2 Potassium reacts with cold water very slowly. 2K + 2h2O ---\> K2OH+H2 Different stages of oxidation is written as (example is iron) Iron l - Iron 1 is generally the less oxidised. Iron ll Iron lll\ Some elements can have more oxidation levels. Ruthenium has up to +8 and molybdenum has low as -2. **Reactions with steam and metals.** Metal + H2o (g) ---\> **Metal Oxide** + Hydrogen gas. Aluminium has a thin layer of oxide that prevents aluminium from further oxidation. Aluminium only reacts to steam when that oxide layer is removed. 2Al + 3H2o (g) ---\> Al2O3 + H2 Magnesium, being way too overactive like edog **after a joke reacts vigorously.** Mg + H2o (g) ---\> MgO +H2 Iron and zinc only react when the steam is heated strongly. Zn + H2o (g) ---\> ZnO + H2 **Non metals, allotropes and their properties** Non metals do not have anything such as lustre, malleability and ductility. They are very bad conductors of electricity (With the exception of graphite). Allotropes are different forms of the same element.\ For example, allotropes of carbon include diamonds and graphite. Graphite or diamond is an allotrope of carbon. Oxygen Oxygen is a non metal/gas found in 21% of the earth\'s asthenosphere or 50% of earth\'s crust. Oxygen is needed for a fire, as the chemical reaction between oxygen and certain elements releases heat energy, which reacts with oxygen and thus creates fire. Allotrope of oxygen - **Ozone** The chemical formula for oxygen is O2, while ozone is O3. Therefore we can say ozone is an allotrope of oxygen. When energy, in the form of an electric spark, goes through oxygen gas, it creates ozone. Ozone has many uses, such as protecting the earth from harmful UV light. It also can be used for filtering pools. Ozone can be used to filter pools, and is a substitute option for chlorine. - - - **Carbon allotropes** Diamond is a hard allotrope of carbon. It is used for jewellery, as its lustre (I probably shouldn\'t be using lustre - Lustre is not used for non metals but I really couldn\'t find a more smarter sounding word then lustre). Diamonds hardness is used for construction, and its hardness is used for the end of construction tools such as drills and chainsaws. **Chlorine** Chlorine is a natural yellow gas that is poisonous and attacks the lungs. Its use is to clean drinking water and pools. When it is mixed with water, it cleans the water, while making the water more acidic, and producing HOCL, or hypochlorous acid. Hypochlorous acid is a weak acid and can make the water more acidic. When mixed with water, Hypochlorous acid partially dissolves and forms hydrogen ions (h-) and hypochlorite ions (ocl)- Sodium hydroxide added to chlorine creates bleach, or sodium hypochlorite or NaOCl.\ Bleach usually cleans clothing material and is toxic just like ethans desk. Nitrogen Nitrogen is a gas that makes up the majority of the gas in the atmosphere, which contains 78% nitrogen. Nitrogen is an unreactive element, with the exception of when lightning strikes nitrogen. Lightning makes it so oxygen and nitrogen react and form nitric oxide. N2+O2 → 2NO This nitric oxide reacts with oxygen and produces nitrogen dioxide. 2NO+O2 → 2NO2 **Sulphur** Sulphur is a naturally occurring, brittle solid that is found near volcanoes. Due to it being brittle, it is often found as a power.\ \ Sulphur goes through some weird changes once it is heated beyond its melting and boiling point. S + O2 → SO2 When sulphur is combined with oxygen, it burns and creates sulphur dioxide, which is a gas that irritates the respiratory system. When Sulphur dioxide is combined with water, it creates an acid which affects the environment severely. **Covalent bonding\ **Covalent bonding is a type of bond where it is usually with non metals. The bonding forms with 2 atoms which are usually both nonmetals, and they share electrons which makes them stick together., NOT giving an electron like ions. Covalent bonds can have a single, double, triple and very rarely a quadruple covalent bond. The more bonds there are, the stronger the bonding is between elements.  **Acids, bases and neutralisation** The pH scale is a scale that is used to calculate how acidic a solution/solute is. pH stands for "Potential of hydrogen". Low pH has low hydrogen levels so it\'s acidic and vice versa. The scale varies from pH level 1 to 15. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Acidic Neutral Basic/Alkaline Acids are substances that form acidic solutions when mixed with water. Bases are substances that neutralise acids when mixed together. Neutral is when a solution (Such as water) is neither acidic or neutral and has a pH of 7. Acids have more H+ the more acidic it gets.\ \ Bases contain OH- or peroxide. The more basic a solution is the more peroxide it contains. Neutralisation is when an acid is added to a basic solution, and therefore makes the solution near the "middle" of the pH scale. Carbonate Neutralising a solution always creates 2 substances. A random type of ionic salt. ( For example, if hydrochloric acid (HCl) and sodium hydroxide (NaOH) mix, the H+ from the acid and the OH- from the base combine to form water and the Cl and Na create NaCl or table salt. ) Water (As when OH- and H+ are mixed they create H2O as a chemical reaction) **Carbonate** **Organic chemistry** Organic chemistry is a branch of chemistry that mainly focuses on carbons. And Alkanes are molecules whose main element is carbon. One of the simplest forms of alkanes are hydrocarbons, or molecules that only contain carbon and hydrogen. Hydrocarbons are generally easily combustible, as they are mostly oils. Each substance of a hydrocarbon is structured as\ Molecular formula - CH4 and indicates the amount of each atom that is in a substance Structural formula - Indicates the amount of each atom that is in a substance written as a diagram Structural formula of methane, CH4 The general formula for hydrocarbons are [*X*nH2*n* + 2 ]{.math.inline}Where N can be any finite number. POLYMERS are long strands of natural or synthetic (chemicals that are meant to imitate natural substances) which are called monomers. These of which are repeated several times. They are very large. Polymers make up macromolecules, which are huge molecules. Alkanes are quite simple hydrocarbons and any alkane that follows the formula [*X*nH2*n* + 2 ]{.math.inline}is classified as an alkane.\`  **Polymerization** Polymerization is the chemical process of creating polymers. Keep in mind that almost all monomers either have a double or a triple covalent bond. Polymerization example This is a hydrocarbon, called ethene (CH4). It is like this one below. When they want to polymerize, they remove one of their covalent bonds, from double to single, they turn into this: They can then have more ethene on the left and right and can form a polymer and create polyethylene, the most common type of plastic.  Polyethylene **Alcohol** Alcohol is a compound that has at least 1 hydroxyl/ -OH which replaces one of the hydrogen atoms in an alkane. Alcohol is used as fuel and in alcoholic beverages, which stimulate the nervous system temporarily.  Ethanol Ethane Ethanol is the most common alcohol. Burning alcohol is a great source of energy. Well, any hydrocarbon itself burning is a great source of energy. They are easily combusted (Destroyed by fire). Catalyst is a compound that speeds up a chemical reaction.The catalyst is not consumed in the process.  This is another way to write propanol. The other way of writing propanol is There are 3 lines on the top diagram, for 3 carbon atoms. Butanol looks like  4 lines for 4 carbon atoms A zigzag forms from ethanol onwards. **Ethanol production by fermentation/Alcohol production by chemicals breaking down** (Ethan)ol or CH3CH2OH is produced when fruit juice (most commonly grape juice) is fermented by yeast. 2C6H12O6 + H2O → 2C2H5OH + 2CO2 Fermentation by yeast **\ Types of reactions** Combination reactions - Chemical A + Chemical B → Chemical AB When 2 chemicals combine to one 2MG + O2 → 2MGO Decomposition reaction - Chemical AB → Chemical A + Chemical B When a chemical splits into 2 chemicals are simpler chemicals Displacement reaction - Chemical A + Chemical BC → Chemical AC + Chemical B When one chemical replaces another via a reaction Exchange reaction → Chemical AB + Chemical CD → Chemical AC + Chemical BD When an ION in a compound replaces another ion to create 2 new compounds. **Combination and decomposition reactions.** Combination equations\ Na + Cl → NaCl Decomposition Example : When copper carbonate is heated, it\'s off a solid version of copper oxide and letting off carbon dioxide. CuCO 3 (s) → ∆ CuO (s) + CO2 (g) (delta or the triangle means "time" meaning that the equation will happen with time.) All chemicals break down at a specific temperature as chemical bonds break down from the energy of heat. **\ ** **Precipitate, spectator ions, and reactions based on breaking down and displacement** When 2 chemicals, with at least 1 aqueous solution react, it forms a precipitate, or a non dissolvable compound. This forms when ions are combined, as when ions are formed, some atoms are left out and precipitate. When a reaction forms precipitate, it is said to be precipitated. In a chemical equation, the precipitate is written as a solid, or (s). For example: Calcium Nitrate + Sodium sulphate → calcium sulphate + Sodium nitrate Ca(NO3)2 + Na2SO4 → CaSO4 + 2NaNo3 (s) Aqueous solution Precipitate "Sodium sulphate is precipitated during this reaction, creating sodium nitrate as the precipitate." Spectator ion A spectator ion is an ion that exists before and after a chemical reaction. This information is used to simplify chemical equations, by cancelling each other out on both sides. Keep in mind positive charged ions are generally placed first in a chemical formula\ For example, in NaCl, Na is a + charge. Ca(NO3)2 + Na2SO4 →CaSO4 (s) + 2NaNO3 Can be written as (Ca2+) + (2NO3-) + (Na2+) + (SO4\^2-) → (Ca+) + (SO-4) + (2Na+) + (2NO-)3 You can cancel out (Ca2+) + (2NO-)3 + (Na2+) + (SO4\^2-) → CaSO4 (s) + (2Na+) + (2NO-)3 Yellow is cancelled out substances. The final equation is: (Ca2+) + (SO4\^2-) → CaSO4 (s) + (2Na+) That is it!! This is about 90-95% of NCEA lvl 1 chemistry. Words and definitions - - 1 more ion One less ion This does not mean the hydrogens cancel out H2O 1 hydrogen each side = 2 in H2O SPECTATOR IONS