Results for "sulphur"

4. Metals and Non-metals Learning Objectives By the end of the lesson, you will be able to: ☑ distinguish between metals and non-metals ☑ describe the physical and chemical properties of metals and non-metals ☑ list the uses of some metals and non-metals MINERALS AND ORES You have learnt that all materials Here is the exact text from the image:are made up of basic substances called elements, and that elements cannot be split into simpler substances by chemical methods. There are 118 known elements. Sodium, zinc, gold, mercury, iron, lead, barium and tin (metals); and hydrogen, oxygen, carbon, sulphur, chlorine, boron, neon and radon (non-metals) are some examples. Only certain unreactive elements are found free in nature. Others occur in combined states as minerals. A mineral is a solid inorganic substance that is found in nature. A mineral deposit that can be mined and from which an element or compound can be obtained profitably is known as an ore. Elements can be broadly classified into two groups—metals and non-metals. Table 4.1 Some common ores Fig. 4.1 Some common ores a. Bauxite (aluminium) b. Malachite (copper) c. Haematite (iron) d. Galena (lead) e. Apatite (phosphorus) f. Quartz (silicon) -- --- METALS All except 20 of the known elements are metals. Most metals are reactive; they combine with other elements in nature, such as oxygen and sulphur, and occur as oxides, sulphides and carbonates. Only a few unreactive metals like gold, silver and platinum are found as free metals in the Earth's crust. Physical Properties of Metals Metals are solids at room temperature, except mercury, which is a liquid at room temperature (Fig. 4.2(a)). They are generally hard and strong, with a few exceptions such as sodium and potassium, which are soft and can be easily cut with a knife (Fig. 4.2(b)). They have a metallic lustre (shine), especially when freshly cut. They have high melting and boiling points, with a few exceptions like sodium, potassium and mercury. They are good conductors of heat and electricity. Silver and copper are the best conductors of electricity, followed by gold and aluminium. Metals are sonorous. They produce a ringing sound when struck. Most metals have high tensile strength. They can take heavy loads without breaking. They are malleable. Metals, with exceptions like sodium and potassium, can be beaten into thin sheets and foils. They are ductile. Metals, with exception like sodium and potassium, can be drawn into wires. Most metals have high density. However, sodium and potassium have low density and float on water. Fig. 4.2 Special metals a. Mercury b. Sodium --- Chemical Properties of Metals Reaction with oxygen Metals react with oxygen under different conditions to form basic oxides. These basic oxides react with water to form bases. Sodium and potassium react vigorously with oxygen at room temperature. 4Na + O_2 \rightarrow 2Na_2O To prevent this oxidation, sodium and potassium are stored under kerosene. Magnesium reacts with oxygen only when ignited. It burns with a dazzling bright flame and forms a white powder of magnesium oxide. 2Mg + O_2 \rightarrow 2MgO Copper and iron react with oxygen only when heated to a very high temperature. 2Cu + O_2 \rightarrow 2CuO --- --- Reaction with water Metals react with water to form hydroxides or oxides, along with hydrogen. Different metals react at different temperatures. Sodium, potassium, and calcium react with cold water to form hydroxides. 2Na + 2H_2O \rightarrow 2NaOH + H_2 Magnesium Reacts with steam or hot water to form magnesium oxide. Mg + H_2O \rightarrow MgO + H_2 Aluminium Forms an oxide too, but this oxide forms a protective covering over the metal and prevents further reactions. 2Al + 3H_2O \rightarrow Al_2O_3 + 3H_2 Zinc Reacts only with steam. Zn + H_2O \rightarrow ZnO + H_2 Iron Reacts with steam when heated strongly. 2Fe + 3H_2O \rightarrow Fe_3O_4 + 3H_2 Copper, gold, silver, and platinum do not react with water at all. --- Activity 4.1 Teacher Demonstration Aim: To study the reaction of metals with water. [Caution: This activity should be demonstrated by the teacher, and students should stand away from the table.] Materials required: Two 200 mL beakers Pieces of sodium and calcium Forceps Knife Litmus papers Water Method: 1. Fill each beaker with 100 mL of water. 2. Using forceps and a knife, cut a small piece of sodium. 3. Dry it on a tissue paper and drop it into one of the beakers. 4. Repeat the same procedure with calcium. 5. Test the water in both the beakers with red and blue litmus papers. Observations and Conclusions: Sodium reacts vigorously and may explode. A gas is also released. The reaction with calcium is quick, though not as vigorous as that with sodium. In both cases, the red litmus paper turns blue, showing that the solutions are bases. --- Reaction with dilute acids Most metals react with dilute acids to form their salts and liberate hydrogen gas. The reaction with reactive metals like sodium, potassium, and calcium is violent. Magnesium, aluminium, zinc, and iron do not react violently. Mg + 2HCl \rightarrow MgCl_2 + H_2 Copper, silver, gold, and platinum do not react with dilute acids. --- Reaction with bases Only some metals such as aluminium and zinc react with strong bases like sodium hydroxide to liberate hydrogen gas. Zn + 2NaOH \rightarrow Na_2ZnO_2 + H_2 --- Activity 4.2 Aim: To study the reaction of metals with dilute hydrochloric acid. Materials required: Sandpaper Six test tubes Dilute hydrochloric acid Strips of magnesium, zinc, iron, tin, lead, and copper Method: 1. Clean the metal strips with sandpaper. 2. Add dilute hydrochloric acid to the six test tubes. 3. Insert a strip of metal into each test tube. Observe if any bubbles are formed in the test tubes. If no bubbles are seen, warm them gently in a beaker of hot water. 4. Observe the speed at which gas is generated. This gives an idea of the speed of the reaction. 5. Classify the metals in order of their reactivity with dilute hydrochloric acid. [Caution: Acids are corrosive and should be handled carefully.] --- Activity 4.3 Aim: To study the reaction of metals with bases. Materials required: Small piece of zinc Beaker Sodium hydroxide Method: 1. Prepare warm sodium hydroxide or caustic soda solution. 2. Drop the piece of zinc into it. Observations and Conclusions: You will notice that zinc reacts with sodium hydroxide to liberate hydrogen gas. Observations on Metals with Dilute Acids Metals like sodium, potassium, and calcium react violently with dilute acids to liberate hydrogen gas. Magnesium, aluminium, zinc, and iron also displace hydrogen from dilute acids, but the reaction is not violent. Metals such as copper, silver, gold, and platinum do not displace hydrogen from dilute acids. --- Activity Series of Metals The activity series of metals is the arrangement of metals in decreasing order of reactivity. The series in the book shows reactivity decreasing from top to bottom. Potassium is the most reactive metal while gold is the least reactive. --- Displacement of a Metal by Other Metals A more reactive metal displaces a less reactive metal from its compounds in an aqueous solution. Some examples: Mg + CuSO_4 \rightarrow MgSO_4 + Cu Zn + FeSO_4 \rightarrow ZnSO_4 + Fe Iron can displace copper from copper sulphate solution (as shown in Activity 4.4). The solution turns green, and reddish-brown copper deposits on the iron nail. Copper cannot displace iron from iron sulphate solution, showing that copper is less reactive than iron. Cu + FeSO_4 \rightarrow \text{No reaction} Question: What do you think will happen if you place a silver spoon in copper sulphate solution? --- Activity 4.4 - Displacement Reaction Aim: To study a displacement reaction. Materials Required: Test tube Iron nail Copper sulphate solution Method: 1. Fill the test tube with copper sulphate solution (blue in colour). 2. Place the clean iron nail in the solution. Observations and Conclusions: After about an hour, the solution changes to green, and a reddish-brown deposit is formed on the iron nail. --- Corrosion of Metals Corrosion is the destruction or damage of a material due to chemical reaction. Rusting of iron happens when iron is exposed to moist air, forming a reddish-brown layer of rust. Rust is iron oxide, which eventually flakes off, damaging the object. Definition written on the page: "Slow eating of a metal’s surface due to oxidation is called corrosion of metals." --Observations on Metals with Dilute Acids Metals like sodium, potassium, and calcium react violently with dilute acids to liberate hydrogen gas. Magnesium, aluminium, zinc, and iron also displace hydrogen from dilute acids, but the reaction is not violent. Metals such as copper, silver, gold, and platinum do not displace hydrogen from dilute acids. --- Activity Series of Metals The activity series of metals is the arrangement of metals in decreasing order of reactivity. The series in the book shows reactivity decreasing from top to bottom. Potassium is the most reactive metal while gold is the least reactive. --- Displacement of a Metal by Other Metals A more reactive metal displaces a less reactive metal from its compounds in an aqueous solution. Some examples: Mg + CuSO_4 \rightarrow MgSO_4 + Cu Zn + FeSO_4 \rightarrow ZnSO_4 + Fe Iron can displace copper from copper sulphate solution (as shown in Activity 4.4). The solution turns green, and reddish-brown copper deposits on the iron nail. Copper cannot displace iron from iron sulphate solution, showing that copper is less reactive than iron. Cu + FeSO_4 \rightarrow \text{No reaction} Question: What do you think will happen if you place a silver spoon in copper sulphate solution? --- Activity 4.4 - Displacement Reaction Aim: To study a displacement reaction. Materials Required: Test tube Iron nail Copper sulphate solution Method: 1. Fill the test tube with copper sulphate solution (blue in colour). 2. Place the clean iron nail in the solution. Observations and Conclusions: After about an hour, the solution changes to green, and a reddish-brown deposit is formed on the iron nail. --- Corrosion of Metals Corrosion is the destruction or damage of a material due to chemical reaction. Rusting of iron happens when iron is exposed to moist air, forming a reddish-brown layer of rust. Rust is iron oxide, which eventually flakes off, damaging the object. Definition written on the page: "Slow eating of a metal’s surface due to oxidation is called corrosion of metals." Uses of Metals (Continued) Aluminium Used in high-voltage electric lines. Alloys like duralumin and magnalium are used in aircraft and automobile bodies. Used for making aluminium foil and cooking utensils. Copper Good conductor of electricity → Used in electrical wires, cables, motors, and transformers. Good conductor of heat → Used in the bottoms of stainless steel vessels. Zinc Used to make corrosion-resistant galvanised iron (GI) pipes and sheets. Used as an electrode in dry cells. Other Metals Gold and silver → Used in jewellery. Lead → Used in electrodes of lead storage batteries (used in automobiles and inverters). Chromium → Used for electroplating iron to give a shiny, corrosion-resistant finish. --- Looking Back (True/False Statements) 1. Gold, silver, and platinum are found in the Earth’s crust as free metals. → True 2. Most metals are solids that are soft. → False 3. Metals such as zinc and magnesium react with dilute acids to liberate oxygen. → False 4. A less reactive metal displaces a more reactive metal from its aqueous solution. → False 5. The chemical name of rust is zinc oxide. → False (Rust is Fe₂O₃.xH₂O) 6. Coating zinc objects with iron is called galvanising. → False (Galvanising is coating iron with zinc) Non-Metals Physical Properties of Non-Metals Exist as gases or solids at room temperature (except bromine, which is liquid). Not as hard as metals (except diamond, which is very hard). Low tensile strength and low density. Low melting and boiling points (except graphite). Not sonorous (do not produce a ringing sound). Not malleable or ductile (cannot be beaten into sheets or drawn into wires). Do not have lustre (except iodine and graphite). Bad conductors of heat and electricity (except graphite, and silicon under specific conditions). --Chemical Properties of Non-Metals Reaction with Water Most non-metals do not react with water. Highly reactive non-metals (e.g., phosphorus) catch fire in air, so they are stored in water. Fluorine, chlorine, and bromine react with water to form acids. Reaction with Oxygen Non-metals react with oxygen to form acidic or neutral oxides. Carbon and sulfur react with oxygen to form acidic oxides, which dissolve in water to form acids. Some oxides (e.g., CO, N₂O) are neutral and do not form acids. Examples: Carbon + Oxygen → Carbon Dioxide (CO₂) CO₂ + Water → Carbonic Acid (H₂CO₃) Sulfur + Oxygen → Sulfur Dioxide (SO₂) SO₂ + Water → Sulfurous Acid (H₂SO₃) Reaction with Acids Unlike metals, non-metals do not replace hydrogen in acids. Silicon reacts with hydrofluoric acid (HF). --Uses of Non-Metals Hydrogen Used in the manufacture of ammonia and industrial chemicals. Used in vanaspati (a cooking oil). Oxygen Used in breathing support systems in hospitals. Used with other gases in equipment to weld metals. Sulphur Used in the manufacture of sulphuric acid, sulphur dioxide gas, and other industrial chemicals. Used to make pesticides for agriculture. Used in vulcanising rubber (making it harder) and in gunpowder. Nitrogen Used in the manufacture of ammonia and nitrogenous fertilisers like ammonium nitrate and ammonium sulphate. Used as an inert gas in processed food packaging to prevent rancidity. Silicon Used in making semiconductors for microchips. Silicates (oxides of silicon) are used in making glass. Other Non-Metals Phosphorus: Used in making fertilisers (superphosphates). Chlorine: Used for disinfecting drinking water. Argon: Used in welding stainless steel and filling electric bulbs. Helium: Used in balloons for meteorological observations. Neon: Used in fluorescent lights for advertisement displays

Sulphur cycle

ACIDS a) Sulphuric Acid: H250, Commercial names: oll of vitriol, "battery acid" Propert/es: • good dehydrating agent (I.e. removes water from substances) • strongly exothermic reaction when mixed with water • concentrated form chars some types of organic material (e.g. sugars) as a result of dehydrating action • reacts with some metals, but often slowly • good electrolyte (conducts electricity) • concentrated sulphuric acid is 98% HSO, and 2% water (18 M HSO4) Common uses: • production of sulphates • manufacturing fertilizers, explosives, dyes, insecticides, detergents, plastics • used to absorb waler and keep chemicals/nonaqueous solutions free of water • used in car batterles as an electrolyte b) Hydrochloric Acid: HCI Commercial name: • muriatic acid Properties: • good electrolyte • concentrated solutions have a choking odour • reacts with some metals, but often slowly • concentrated hydrochloric acld is 37% HCl In water (12 M HCI) Common uses: • production of chlorides • cleaning metal products (removes metal oxides) and bricks • catalyst in some chemical reactions • "stomach acid" is a dilute solution of HCi; stomach acid activates a protein-digesting biological calalyst called an "enzyme" • removing "boller scale", which consists of calcium and magnesium carbonate •) Nitric Acid: HNO Commercial name: (none, other than "nitric acld") Properties: • colours protein yellow (this is a nonspecille test for the presence of protein). Hence, turns skin yellow on contact. • very reactive, quickly attacks almost all metals • concentrated nitric acid is 69% HNOg In water (16 M HNOg) Common uses: • production of nitrates • manufacturing fertilizers, explosives, dyes d) Acotic Acid: CHCOOH Commercial name: 5% aqueous solution is called "vinegar" Properties: • non-electrolyte when concentrated (99 - 100%, 17 M); weak electrolyte when diluted • only affects highly reactive metals Common uses: • making acetates • food preservation ("pickles") • manufacturing textlies and plastics

Chemistry - Sulphuric Acid

11 - sulphuric acid

Ch2 Sulphur

5.01 : Metals in the earths crust The composition of the Earth’s crust we get some metals from the sea but most from earths crust.The Crust is the outer llayer of the Earth. It is huge mixture of many different compunds. It also contains elements such as sulphur,copper,silver,platinum and gold. These occur uncombined, or native, because they are unreactive. if you could dig up the earths crust and break down all the comnpunds, you would find it is almost half oxygen! its composition is oxygen 45% ( nearly one-fourth ) silicon 27% ( over one foruth) all other metals and non-metals 2% pottasium 1.5% sodium 2.5% magnesium 3% calcium 5% iron 6% aluminium 8% Nearly three-quarters of the earth’s crust is made up of just two non-metals, oxygen and silicon. These are found combined in compunds such as aluminium oxide,iron oxide,and calcium carbonate. the rest of the crust consists mainly of just six metals.Aluminium is the most abundant of these, and iron is next.None of the six is found uncombined, because they all are reactive metals,and reactice metals like to form compounds. Some metals are scarce : look again at the pie chart above. it shows that there are just 6 plentiful metals. all the other metals together make up less than one-fifth of the earths crust,so they are not plentiful. copper zinc mercury silver lead gold tin platinum the scarce metals are expensive. Even so, we are using them up quicly, and many people are worried that they will soon run out. Metal ores: The rocks in the Earths’s crust are a mixture of many different compounds. But some contain a large amount of single metal compound ,or a single metal,and it may be worth digging up these extracted metals.Rocks which metals are obtained are called ores.Below are some examples: Mine or not to mine? Before starting to mine an ore,the mining company must decide whether it is economical.It must find questions like these: 1.How much ore is there? 2.How much metal will we get from it? 3.Are there any special problems about getting the ore out? 4.How much will it cost? 5.how much will be able to sell the metal for? 6.so will me make a profit if we go ahead? the answers to these questions will change from year to year.if the costs of fuel drops,and the selling price of a metal rises,even a low quality or low-grade ore may be worth mining. The mining company must also think about local community,who may worry that the landscape will be ruined by dust,pits,scars, and that the extraction plant will cause pollution.on the other hand,they may welcome the new jobs tthe mining will bring.

chem sulphur recovery

sulphur and sulphur compounds

Reactions of the halide ions with concentrated sulphuric acid

Biogeochemsitry: lecture 3 - Sulphur and Phosphorus Cycles

Sulphur

Chapter 16:Sulphuric acid

Group 16 elements