Integrated Science Past Paper - Chemistry Basics - 1st Secondary - PDF

Integrated Science1st secondary Chemistry basics # Note # Types of Compounds Mineral acids have H in left alkaline have OH in Right Ex ;- Ex ;- HCI , H2SO...

Integrated Science1st secondary Chemistry basics # Note # Types of Compounds Mineral acids have H in left alkaline have OH in Right Ex ;- Ex ;- HCI , H2SO4 , HNO3 NaOH , Ca(OH)2 , AI (OH)3 OXide have O in Right Salt don’t have H or OH Ex ;- Ex ;- or O only a) Normal Salt : as NaCI Na2O , K2O , CO b) Oxygenated Salt : as KNO3 , Li2SO4 Exercise:- 1- one of the following Compounds is Salt........ ⓐ NaHCO3 ⓑ KOH ⓒ ZnO ⓓ K 2O 2- Zn(OH)2 is …………. ⓐ acid ⓑ base ⓒ oxide ⓓ Salt 3- Ammonium Carbonate is ……… ⓐ acid ⓑ base ⓒ oxide ⓓ Salt Physical state (s) (L) (g) (aq) Solid Liquid Gas aqueous Solution Prof : A.S.El-Azhary 01098391627 1 v  Integrated Science1st secondary ----- unit (1) ---- > Aquatic Ecosystem Chemical Structure of Water Formation from Types of bond Chemical bond physical bond One oxygen atom and Two hydrogen atoms ratio of Atoms 2: 1 mass percent of ( O ) in water= 88,89% Covalent Bond Hydrogen Bond mass percent of ( H ) in water= 11,11% in the same Molecule between Molecules the Angle between (2 covalent bond) equal 104.5 Chemical properties of water: Water does not exist on the Earth's surface in a pure form, as it contains many ions and Chemical substances that interact with water by different ways. From the chemical properties of water: 1-Polarity of water: The oxygen atom is characterized by its higher electronegativity than the hydrogen atom, so the electrons of bond are attracted towards the oxygen atom, forming a partial negative charge on the oxygen atom and a partial positive charge on the hydrogen atom, which is known as polarity of water molecule. What are the consequences of the polarity of water molecule? The polarity of water molecules causes: 1- Their bending with other water molecules which is called hydrogen bonds 2- Gives water the ability to dissolve many salts and break them down into hydrated ions covalent bond EX: solubility of Sodium chloride in water: NaCl + H₂O (l) Na+ (aq) + Cl- (aq) Prof : A.S.El-Azhary 01098391627 2 v  Integrated Science1st secondary Give reason for The high boiling point of pure water, reaches 100 C ? Due to the ability of water molecules to form hydrogen bonds between its molecules # Note # 1- high boiling point of pure water, which reaches 100 C under normal atmospheric pressure compared to the temperature of Water 2-Compared to the Boiling point of compounds similar to it in composition, such as hydrogen sulfide(H2S) , which boils at 61- 2- Hydrolysis (hydration) :( water is a weak ionized ) A small percentage of water molecules are in the form of hydrogen ions (H) and hydroxide ions (OH), and as a result of chemical reactions with various compounds, some salts present in natural waters are hydrolyzed, which affects the balance of these ions, causing the acidity or basicity of the water 3- Acid-base balance: The acid-base balance in water depends on the relationship between the concentration of hydrogen ions (H) and hydroxide ions (OH). This relationship can be identified by the value of what Describes the pH of the solution. pH Scale > Acid neutral Base 0 increase 7 increase 14 pH value of water from different sources: Source of Clouds Fresh water Distilled Ground water Sea water water rivers and lakes water pH value 4.5 to 5 6.5 to 8.5 7 Varies by region 7.5 to 8.4 Type of water Acidic Acidic - Basic Neutral various Basic Reason Dissolving of Dissolving of Pure The rock Dissolving CO2 and Some salts in Composition of Basic Some Acidic Water in The region Salts oxides Prof : A.S.El-Azhary 01098391627 3 v  Integrated Science1st secondary These values can vary depending on different environmental factors, human activities in that area which can affect the pH level when clouds or rainwater are forme Different Spheres on Earth planet : 1- Earth is characterized by hydrosphere than other planets in the solar system 2- Water covers about 70% of the Earth's surface, About 97% of this liquid water is found in oceans, seas, and salt lakes as salt water. 3- The remain part is fresh water found in rivers, lakes, and groundwater. 4- Water vapor (water in the gaseous state) is considered one of the components of the atmosphere. 5- the cryosphere, which refers to the frozen water in the polar regions, mountain peaks, and Glaciers 6- Egypt is characterized by the diversity of its aquatic environments, which include the Nile River, the Gulf of Suez, the Gulf of Aqaba, the Red Sea, the Mediterranean Sea, and many salt and freshwater lakes. Water cycle in nature 1 -Water exists on earth surface or near the Earth's surface, it changes between its three states. 2 -Water is constantly moving from one place to another through many different paths that form a closed system called the water cycle in nature or the hydrological cycle and the water cycle as a system can changing the Earth's surface physically, chemically and biologically. Soil 3 -The water cycle in nature mainly includes the process of: 1- evaporation, which contributes to the formation of clouds, 2- rain or snow falling 3- other biological processes such as transpiration in plants and respiration of plants and animals 4- processes ses of water leakage through the pores of soil and sedimentary rocks to form groundwater. # Note # Water vapor in clouds may react chemically with compounds found in the air, forming acids that fall as acid rain, which dissolves the rocks # Note # Solubility of Water : (( Likes dissolve likes )) H2O is Polar Solvent dissolve 1- Ionic Compound , 2- Polar Compound Prof : A.S.El-Azhary 01098391627 4 v