Module 1 Support pack for Basic agricultural chemistry GR11

Study & Master Support Pack | Grade 11 CAPS Module 1 Units 1 – 7 Agricultural Sciences Basic agricultural chemistry This support pack for the Basic agricultural chemistry module in the Agricultural Sciences Grade 10 CAPS curriculum provides valuable revision activities. All activities have the answers provided. Learners can work through these individually at home or these could form the basis of a catch-up class or online lesson. You have permission to print or photocopy this document or distribute it electronically via email or WhatsApp. For more information on our Study & Master CAPS-approved  textbooks and valuable resource materials, visit www.cambridge.org Brighter Thinking | Better Learning

Module 1 – Basic agricultural chemistry Unit 1 Introduction to basic chemistry Short questions 1. Various possible answers are provided for the following questions. Write only the correct letter (A–D) next to the question number. 1.1 The smallest particle of matter that cannot be chemically broken down further: A molecule B atom C liquid D solid 1.2 Matter in its densest state: A molecule B atom C liquid D solid 1.3 All the known chemical elements arranged in order of their atomic numbers: A periodic table B table of chemicals C elemental list D chemistry dictionary  (3 × 2 = 6) 2. Supply ONE word/term for each of the following descriptions. Write only the word/term next to the question number. 2.1 Group of two or more atoms bound together to form a compound 2.2 Element short of an electron 2.3 Solution with an excess of H+ ions 2.4 Solution with too few H+ ions 2.5 Neutral charge within an atom 2.6 Negative charge within an atom 2.7 Total mass of an atom of an element 2.8 A core, or centre 2.9 Outermost shell of an atom 2.10 Another word for a watery or water-based solution  (10 × 2 = 20) Longer questions 3. Explain the difference between abiotic matter and biotic matter. (4) 4. Why is a knowledge of chemistry important in Agricultural Science? (3) 5. What is chemistry? (3) 6. Explain what this simple demonstration conveys about matter.  (4) S T U DY & M A S T E R S U P P O R T PA C K S 1

Unit 2 Chemical bonding Short questions 1. Various possible answers are provided for the following questions. Write only the correct letter (A–D) next to the question number. 1.1 Something made up of two or more elements in definite proportions by weight: A atom B molecule C ion D compound 1.2 The atomic bond formed by sharing electrons: A covalent B ionic C organic D inorganic 1.3 This chemical bond occurs when an anion and a cation together form a compound: A covalent B ionic C organic D inorganic  (3 × 2 = 6) 2. Supply ONE word/term for each of the following descriptions. Write only the word/term next to the question number. 2.1 Bond where two pairs of electrons are shared 2.2 Ion with a negative charge 2.3 Ion with a positive charge 2.4 Compound with a bond leading to it dissolving easily in water or other solvents 2.5 Clear, odourless, tasteless liquid being a compound of hydrogen and oxygen 2.6 Outermost electron shell in an atom 2.7 Classic example of a metal bonding with chlorine to form a salt 2.8 The type of bond in the example in 2.7 2.9 Symbol used to show a triple bond 2.10 Word to describe fixed proportions of elements in, for example, a compound  (10 × 2 = 20) Longer questions 3. Explain what is being shown inatomsthe following diagram. sharing of electrons  (4) molecule 4. Name the THREE elements that make up a molecule of the following compound: C6H12O6(3) 5. Explain the importance of inorganic compounds in nature.  (4) 6. Do you think Agricultural Science is more concerned with bonding within organic or inorganic compounds? Explain your answer. (2) Unit 3 Inorganic and organic compounds Short questions 1. Various possible answers are provided for the following questions. Write only the correct letter (A–D) next to the question number. 1.1 The branch of chemistry dealing with non-living things: A physical chemistry B biological chemistry C organic chemistry D inorganic chemistry 1.2 The branch of chemistry dealing with living things, especially the element carbon: A physical chemistry B biological chemistry C organic chemistry D inorganic chemistry 2 S T U DY & M A S T E R S U P P O R T PA C K S

1.3 A graphical representation of molecular structure, showing how the atoms are arranged: A chemical formula B biological formula C structural formula D physical formula  (3 × 2 = 6) 2. Supply ONE word/term for each of the following descriptions. Write only the word/term next to the question number. 2.1 Dot structure diagrams that show the bonding between atoms of a molecule 2.2 Gas used by plants in the photosynthesis process 2.3 Far and away the most important liquid on Earth 2.4 Very common type of mineral salt 2.5 Common, fairly unreactive element that is important in most life forms 2.6 Small groups of atoms (two to four) within a molecule that are responsible for certain properties of the molecule and the reactions in which it takes part 2.7 Compounds made up of long, repeating chains of atoms like beads on a string 2.8 In chemistry, the common word used to describe ‘one’, or ‘single’ 2.9 Two or more bound atoms that form part of a molecule, that have at least one free, unpaired electron 2.10 Important gas supporting burning, or combustion  (10 × 2 = 20) Longer questions 3. Explain the importance of inorganic compounds in nature. (4) 4. Explain why carbon is such a significant element.  (6) 5. Discuss the role of water as an important compound. (5) 6. A hydroxyl is a functional group. 6.1 Name the two elements it is comprised of.  (2) 6.2 What is the charge on a hydroxyl? (1) Unit 4 Alkanes and alcohols Short questions 1. Various possible answers are provided for the following questions. Write only the correct letter (A–D) next to the question number. 1.1 The compound containing only the elements carbon and hydrogen: A hydroxyl B hydrocarbon C carbonate D water 1.2 Alkanes can also be described as a type of: A hydroxyl B hydrocarbon C carbonate D water 1.3 Organic compounds having the same molecular formulae, but different arrangements of atoms (structures): A gases B liquids C isomers D solids  (3 × 2 = 6) 2. Supply ONE word/term for each of the following descriptions. Write only the word/term next to the question number. 2.1 Another name for methyl alcohol 2.2 Another name for ethyl alcohol 2.3 Another name for a liquid in which certain substances will dissolve 2.4 Hydrocarbon where one or more of the hydrogen atoms have been replaced by an hydroxyl (–OH) 2.5 Gas by-product from burning alcohol 2.6 Poisonous form of alcohol that causes blindness if consumed 2.7 Alcohol type produced by fermenting sugars 2.8 Bottled cooking gas; highly flammable S T U DY & M A S T E R S U P P O R T PA C K S 3

2.9 Another gas commonly liquefied under pressure and used for cooking and heating 2.10 Gas produced by ruminants such as cattle (10 × 2 = 20) Longer questions 3. Explain the essential difference between an alkane and an alcohol, and give ONE example of each.  (6) 4. Explain briefly what metabolism is and why it is so important. (4) 5. 5.1 What type of alcohol is produced from sugar cane? (1) 5.2 Explain why this type of alcohol is important for the motor industry in countries such as Brazil.  (2) 6. 6.1 List at least FOUR common household products that contain alcohol.  (4) 6.2 Name at least TWO properties of alcohol that make it important in many household products.  (2) Unit 5 Fatty acids and biomolecules Short questions 1. Various possible answers are provided for the following questions. Write only the correct letter (A–D) next to the question number. 1.1 The organic acid characterised by the presence of at least one carboxyl group: A alkane B alcohol C fatty acid D molecule 1.2 Fatty acids that are essential to human and animal diets are called: A alkanes B alcohols C essential fatty acids D proteins 1.3 Which one of the following does NOT qualify as a lipid? A fat B wax C oil D protein (3 × 2 = 6) 2. Supply ONE word/term for each of the following descriptions. Write only the word/term next to the question number. 2.1 Hydrocarbon chain that repels water 2.2 Hydrocarbon chain that attracts water 2.3 Classification of fatty acids relies on the number of _______ atoms in the chemical structure of a molecule. 2.4 Fats and oils that come from plants 2.5 Example of an inedible vegetable fat 2.6 Example of an edible vegetable fat 2.7 Nutrients that dissolve and are carried by fats in a human or animal body 2.8 A substance that can block your arteries and cause heart disease 2.9 A substance that transports and moves chemical energy within cells 2.10 What you need to plan and control so as to eat a healthy selection of food (10 × 2 = 20) Longer questions 3. 3.1 Name the main fat type in each of the following images.  (1) 3.2 Explain the difference between the two fat types. A B (2) 4. Explain why lipids and fats are so important to many living organisms. (6) 4 S T U DY & M A S T E R S U P P O R T PA C K S

5. Explain what is shown in the following diagram, and why it is an important component of soap. hydrophilic (ionic head) soap molecule hydrophobic (non-polar covalent) tail (5) 6. Briefly explain what you understand by the term ‘biomolecule’.  (2) Unit 6 Proteins Short questions 1. Various possible answers are provided for the following questions. Write only the correct letter (A–D) next to the question number. 1.1 The most common natural monomer is: A lactose B fructose C glucose D sucrose 1.2 Proteins are found typically in: A meat B fat C sugar D vitamins 1.3 The building blocks of proteins are: A vitamins B amino acids C sugars D alcohols  (3 × 2 = 6) 2. Supply ONE word/term for each of the following descriptions. Write only the word/term next to the question number. 2.1 Typical bonds found in protein chains 2.2 Element always present in amino acids 2.3 Your body cannot grow without this type of protein 2.4 Rearing or keeping of animals, mainly for protein 2.5 Type of plant-based food that is a good source of protein 2.6 Something that assists, or speeds up a chemical reaction 2.7 Protein components in animal and human immune systems 2.8 The body can convert protein into this substance to provide energy 2.9 Example of a common food containing hardly any protein 2.10 Most abundant structural protein in the human body  (10 × 2 = 20) S T U DY & M A S T E R S U P P O R T PA C K S 5

Longer questions 3. Explain why proteins are so important for living organisms, including humans.  (5) 4. Explain the difference between essential and non-essential proteins, and where your body gets these from.  (4) 5. Describe what is shown in the following diagram: O R H C N C O H H H  (4) 6. Explain why a person who is starving becomes thinner. (4) Unit 7 Carbohydrates Short questions 1. Various possible answers are provided for the following questions. Write only the correct letter (A–D) next to the question number. 1.1 Carbohydrates are mainly a food used by the body for: A growth and development B protection against viruses C healing purposes D energy production 1.2 Which one of these is NOT a typical source of carbohydrate? A bread B pasta C fish D rice 1.3 The simplest form of carbohydrate is a: A monosaccharide B disaccharide C trisaccharide D bisaccharide  (3 × 2 = 6) 2. Supply ONE word/term for each of the following descriptions. Write only the word/term next to the question number. 2.1 Another name for a complex carbohydrate 2.2 Type of natural sugar or saccharide found in fruit 2.3 One of the common elements present in all carbohydrates 2.4 The taste of most simple sugars 2.5 Commonly sugar structures have this form or shape 2.6 Complex carbohydrate found in bread and pasta 2.7 The main structural material of plants, which humans cannot digest 2.8 Process by which plants convert carbon dioxide into carbohydrates 2.9 Chemical substances used in digestion to break down food types 2.10 The most important type of compounds to agricultural scientists (10 × 2 = 20) Longer questions 3. Briefly explain the chemical composition of carbohydrates and simple sugars that sets them apart from other food groups. (6) 4. 4.1 State the importance of glucose. (2) 4.2 Briefly describe the main function of glucose. (2) 5. Differentiate between a simple sugar and a complex sugar. (4) 6. Explain why fats are a more concentrated form of fuel for our bodies, but sugars are more important.  (4) Memorandum Unit 1 Short questions 1.1 B 1.2 D 1.3 A (3 × 2 = 6) 6 S T U DY & M A S T E R S U P P O R T PA C K S

2.1 molecule 2.2 cation 2.3 acidic 2.4 alkaline 2.5 proton 2.6 electron 2.7 atomic mass 2.8 nucleus 2.9 valence shell 2.10 aqueous  (10 × 2 = 20) Longer questions 3. Abiotic matter is non-living matter, such as minerals and water. Biotic matter is living organisms, including plants and animals.  (4) 4. Agricultural Science deals with matter, both non-living (such as the minerals in soil) as well as plant and animal life. Therefore agricultural scientists and farmers need to understand how these things function and work chemically.  (3) 5. Chemistry is the study of the structure and behaviour of matter at atomic and molecular level including how substances react at a microscopic level. (3) 6.1 The diagram illustrates that matter has both volume and mass, and that different substances have different densities.  (2) 6.2 The diagram shows that some substances may have greater mass in smaller volumes than other substances.  (1) Unit 2 Short questions 1.1 D 1.2 A 1.3 B (6) 2.1 double bond 2.2 anion 2.3 cation 2.4 soluble 2.5 water 2.6 valence shell 2.7 sodium 2.8 ionic bond 2.9 2.10 ratio  (20) Longer questions 3. Covalent bonding between two hydrogen atoms and an oxygen atom in a molecule of water  (4) 4. carbon, hydrogen, oxygen  (3) 5. Inorganic compounds are chemical compounds which do not contain carbon-hydrogen bonds. They include water, air and minerals, and are very important in supporting organic structures in living beings, both plants and animals. Trace elements in plant cells include copper, boron, zinc, manganese, and molybdenum. Animals also require manganese, iodine, and cobalt. Iron is an inorganic compound without which animal bodies cannot produce red blood cells. (4) 6. Organic compounds, because Agricultural Science has more to do with the chemistry of biotic compounds, typically carbon, and organic chemistry  (2) Unit 3 Short questions 1.1 D 1.2 C 1.3 C (6) 2.1 Lewis structure 2.2 carbon dioxide or CO2 2.3 water 2.4 sodium chloride 2.5 carbon 2.6 functional groups 2.7 polymers 2.8 mono 2.9 radical 2.10 oxygen  (20) Longer questions 3. Inorganic compounds, including water, air and minerals, support organic structures and living beings, both plants and animals (4) 4. Significance of carbon (any six): •  Carbon plays a very special part in the chemistry of life. S T U DY & M A S T E R S U P P O R T PA C K S 7

•  It is found in many different compounds and is common in the food we grow, in the fibres we produce and in the fuels we use. •  It is able to catenate, which means it can bond with itself, and form long chains with itself. •  It can form single, double and triple bonds with itself. •  Carbon is relatively unreactive with a number of other elements. •  The total flexibility of the carbonic bonding structure means many different shapes and proportions are possible, which means millions of different organic compounds are possible. •  All life is made up of organic compounds. •  Most of the pesticides used in farming are organic compounds.  (6) 5. Water (H2O) is the most important liquid on earth because neither plant nor animal life can exist without it. Water makes up 80% or more of the content of most plant and animal cells. Water is an important solvent, which means that many substances will dissolve in water. (5) 6.1 A single hydrogen and a single oxygen atom (–OH) joined by a single bond  (1) 6.2 A hydroxyl has a negative charge.  (2)  Unit 4 Short questions 1.1 B 1.2 B 1.3 C (6) 2.1 methanol 2.2 ethanol 2.3 solvent 2.4 alcohol 2.5 carbon dioxide or CO2 2.6 methanol 2.7 ethanol 2.8 butane or propane 2.9 butane or propane 2.10 methane  (20) Longer questions 3. Alkanes and alcohols are hydrocarbons. However, in alcohols, one or more of the hydrogen atoms have been replaced by an hydroxyl (–OH). Alkane: methane, butane, propane, ethane, pentane (any one) Alcohol: glycerol, ethanol, methanol (any one) (6) 4. Metabolism is the set of chemical reactions or processes that happen in living organisms to sustain life. These processes allow organisms to grow and reproduce, to maintain their structures and respond to their environments. So, no metabolism, no life. (4) 5.1 Ethanol(1) 5.2 It is used in place of petrol (or blended with petrol) as a fuel.  (2) 6.1  Common household products containing alcohol (any four): medicines, solvents, methylated spirits, cleaning compounds, fuel, mouthwash, alcoholic beverages, cough medicines (4) 6.2 It is a solvent; it is a disinfectant. (2) Unit 5 Short questions 1.1 C 1.2 C 1.3 D(6) 2.1 hydrophobic 2.2 hydrophilic 2.3 hydrogen 2.4 polyunsaturated 2.5 linseed oil 2.6 sunflower oil, olive oil, margarine 2.7 fat-soluble nutrients 2.8 cholesterol 2.9 ATP 2.10 diet  (20) Longer questions 3.1 A: saturated fat. B: unsaturated fat.  (2) 8 S T U DY & M A S T E R S U P P O R T PA C K S

3.2 Unsaturated fatty acids have one or more double bonds between carbon atoms. The double bonds are described as unsaturated, because the pairs of carbon atoms connected by these bonds do not have a complete set of hydrogen atoms attached to them. Saturated fatty acids are long-chain carboxylic acids that usually have between 12 and 24 carbon atoms and have no double bonds. Saturated fatty acids are saturated with hydrogen. (3) 4. The body requires essential fatty acid, for various biological processes, but cannot synthesise them directly. Fatty acids are therefore an important part of human and animal diets. Fats are also an important source of energy storage in the body.  (6) 5. This is a carboxylic acid chain, with a hydrophilic head and a hydrophobic tail. The tail end of the soap molecule is soluble in oily dirt, so it breaks down the dirt. The head is soluble in water, so it carries the dirt away.  (5) 6. A molecule produced by a living organism  (2) Unit 6 Short questions 1.1 C 1.2 A 1.3 B (6) 2.1 peptide bonds 2.2 nitrogen 2.3 essential amino acids 2.4 animal husbandry 2.5 legumes (beans, peas), nuts 2.6 catalyst 2.7 antibodies 2.8 glucose 2.9 starch (or bread, pasta, rice) 2.10 collagen  (20) Longer questions 3. Proteins are important for the growth and repair of muscles, bones, skin, tendons, ligaments, hair, eyes and other tissue in animal and human bodies. Without proteins the body will lack the enzymes and hormones needed for metabolism, digestion and other important functions. (5) 4. Foods from animal sources provide complete protein, which means they contain all the essential amino acids. Beans, peas and peanuts are non-essential protein sources; they are incomplete proteins because they lack some essential amino acids.  (4) 5. This is a complete amino acid containing both an amino group (NH2) and a carboxyl group.  (4) 6. Body tissue (muscle) containing proteins is converted into fuel energy (glucose) to keep the body functioning, so the person becomes thinner as the body consumes itself. (4) Unit 7 Short questions 1.1 D 1.2 C 1.3 A (6) 2.1 polysaccharides 2.2 fructose 2.3 carbon 2.4 sweet 2.5 chains or rings 2.6 starchy carbohydrates 2.7 cellulose 2.8 photosynthesis 2.9 enzyme 2.10 organic compounds  (20) Longer questions 3. Carbohydrates consist of the elements carbon (C), hydrogen (H) and oxygen (O) with ratio of hydrogen twice that of carbon and oxygen. A carbohydrate is a hydrate of carbon. Simple sugars (monosaccharides) are colourless, soluble in water, and have a crystal structure in the solid state. (6) 4.1 Glucose (dextrose) is the most widely distributed sugar in both the plant and animal kingdoms. It is present in blood as blood sugar.  (2) 4.2 It is a major source of energy transported to living cells.  (2) 5. Monosaccharides (example: glucose) or simple sugars are the building blocks of disaccharides (example: sucrose) and polysaccharides (example: starch), which are, chemically, more complex.  (4) 6. Sugars are chemically more simple than fats, easier to digest, and provide instant energy for the body.(4) S T U DY & M A S T E R S U P P O R T PA C K S 9