Mixtures and Pure Substances.ppt
- 1. DO:I will be able to explain the differences between pure substances and mixtures. EQ: 1. How do elements and compounds both qualify as pure substances? 2. Explain how to determine types of mixtures? 3. Compare and contrast pure substances and mixtures.
- 2. 1. The chemical formula for glucose is C6H12O6. How many different elements make up one molecule of glucose? a. 1 b. 3 c.12 d. 24 Explanation: 2. Which of the following is the basis for arranging the elements in the modern periodic table? a. Atomic Name b. Atomic Number c. Atomic Mass d. Atomic Symbol Explaination:
- 5. ELEMENTS COMPOUNDS Elements are the simplest pure substances. Examples: • O-Oxygen • H- Hydrogen • Na- Sodium • C- Carbon • Fe- Iron • Pb- Lead The smallest particle of an element that has the properties of that element is an atom. Compounds are pure substances that are made of more than one element bound together. Examples: • H2O and CO2 A molecule is formed when two or more atoms chemically combine. HETEROGENOUS MIXTURES HOMOGENOUS MIXTURES All components of the mixture are visible because they do not mix together Particles not distributed evenly EX: sand and water vegetable soup oil and water Homogeneous mixtures Components cannot be distinguished from each other, appear as one substance Particles distributed evenly throughout EX: air, salt water, 10 karat gold *SOLUTIONS Pure Substance
- 6. Heterogeneous mixtures All components of the mixture are visible because they do not mix together Particles not distributed evenly EX: trail mix, vegetable soup, oil and water Homogeneous mixtures Components cannot be distinguished from each other, appear as one substance Particles distributed evenly throughout EX: air, salt water, 10 karat gold
- 8. Homogeneous mixtures are also called solutions. Separate particles are not visible because one dissolves in the other = dissolution In salt water, ◦ salt is the solute, gets dissolved ◦ water is the solvent, dissolves other substance
- 9. Q. Why do some substances dissolve and others do not? A. In a solute, each particle is attracted to each other to form a grain of it. When the solute is placed in a water, new attractive forces are present. If the attractive forces between the water and the solute are stronger than those holding the solute together, then the solute will break down and get dissolved in the water.
- 10. Because different amounts of solute can be dissolved in a solvent, we look at a solution’s SOLUBILITY. Definition: The maximum amount of solute that can be dissolved in a given amount of solvent at a specific temperature. Usually expressed as the number of grams of solute per 100mL of solvent.
- 11. Every chemical substance which dissolves in water has a fixed solubility. ◦ If it does not dissolve, solubility = zero. Many of these solublities have been measured and special charts are produced displaying solubility of many substances at once.
- 12. oSaturated: Maximum amount of solute dissolved in solvent oUnsaturated: Less than maximum amount of solute dissolved in solvent oSupersaturated: More than maximum amount of solute dissolved in solvent oDilute: to make less concentrated
- 13. 1. Sedimentation: occurs naturally when solid substances that are heavier than their solvent deposit at the bottom of the mixture. EX: Water treatment 2. Decantation: a heterogeneous mixture that has distinct layers can be separated by slowly pouring one of the layers into another container. EX: Separating cream from milk 3. Filtration: separates parts of a heterogeneous mixture by pouring it though a filter, the larger particles (residue) will be held in the filter while the smaller ones (filtrate) will pass through. EX: Brita 4. Distillation: used to separate components of a homogeneous mixture based on their different boiling points. Solution is heated and substance with lower boiling points evaporates and passes through a tube where it cools and turns back to water in another container.
- 15. DO:I will be able to explain the matter its molecular composition, characteristics, ability to change, and how combinations of elements and atoms from the different types of matter that make up the world. EQ: 1. How do elements and compounds both qualify as pure substances? 2. Explain how to determine types of mixtures? 3. Compare and contrast pure substances and mixtures.
- 17. An atom is to an element as a _____________ is to ____________. An atom is to a molecule as a _____________ is to ____________. An atom is to a compound molecule as a _____________ is to ____________.
- 18. DO:I will be able to explain the matter its molecular composition, characteristics, ability to change, and how combinations of elements and atoms from the different types of matter that make up the world. EQ: 1. How do elements and compounds both qualify as pure substances? 2. Explain how to determine types of mixtures? 3. Compare and contrast pure substances and mixtures.
- 19. ATOM ELEMENT MOLECULE COMPOUND Writing Prompt Explain the correlation between atom, element molecule, and compound.
- 20. ATOM ELEMENT MOLECULE COMPOUND Writing Prompt Explain the correlation between atom, element molecule, and compound.