What happens to most solutes as the temperature of a solvent increases?

They evaporate with the solvent.

What is typically used in science to predict values from a graph?

The mean values before they're plotted.

Saturated solutions

Investigate properties of unsaturated or saturated solutions.

Short Quiz in Science 7 investigate properties of unsaturated or saturated solutions

Components of Sand and Seawater & Separating Mixtures: Solubility and Solutions Seawater is a mixture of water, salts, sand, and other substances. Sand is not dissolved in seawater and can be separated easily. Seawater contains dissolved salts like sodium chloride, which cannot be seen by the naked eye. We use different methods to separate mixtures depending on their properties. Solubility is the ability of a substance (solute) to dissolve in a solvent (like water) to form a solution. A saturated solution is when no more solute can dissolve in the solvent at a given temperature. The solubility of substances is affected by temperature (most solids dissolve better in hot water) and pressure (gases dissolve better under high pressure).

A solution is a mixture in which one or more substances are uniformly distributed in another substance. Solutions can be mixtures of liquids, solids, or gases. For example, plasma, the liquid part of blood, is a very complex solution. It is composed of many types of ions and large molecules, as well as gases, that are dissolved in water. A solute (SAHL-YOOT) is a substance dissolved in the solvent. The particles that compose a solute may be ions, atoms, or molecules. The solvent is the substance in which the solute is dissolved. For example, when sugar, a solute, and water, a solvent, are mixed, a solution of sugar water results. Though the sugar dissolves in the water, neither the sugar molecules nor the water molecules are altered chemically. If the water is boiled away, the sugar molecules remain and are unchanged. Solutions can be composed of various proportions of a given solute in a given solvent. Thus, solutions can vary in concentra- tion. The concentration of a solution is the amount of solute dis- solved in a fixed amount of the solution. For example, a 2 percent saltwater solution contains 2 g of salt dissolved in enough water to make 100 mL of solution. The more solute dissolved, the greater is the concentration of the solution. A saturated solution is one in which no more solute can dissolve. Aqueous (AY-kwee-uhs) solutions—solutions in which water is the solvent—are universally important to living things. Marine microorganisms spend their lives immersed in the sea, an aqueous solution. Most nutrients that plants need are in aqueous solutions in moist soil. Body cells exist in an aqueous solution of intercellu- lar fluid and are themselves filled with fluid; in fact, most chemical reactions that occur in the body occur in aqueous solutions. Copyright © by Holt, Rinehart and Winston. All rights reserved. Liquid water Solid water Ice (solid water) is less dense than liquid water because of the structure of ice crystals. The water molecules in ice are bonded to each other in a way that creates large amounts of open space between the molecules, relative to liquid water. FIGURE 2-12 solvent from the Latin solvere, meaning “to loosen” Word Roots and Origins CHEMISTRY OF LIFE 43 ACIDS AND BASES One of the most important aspects of a living system is the degree of its acidity or alkalinity. What do we mean when we use the terms acid and base? Ionization of Water As water molecules move about, they bump into one another. Some of these collisions are strong enough to result in a chemical change: one water molecule loses a proton (a hydrogen nucleus), and the other gains this proton. This reaction really occurs in two steps. First, one molecule of water pulls apart another water molecule, or dissociates, into two ions of opposite charge: H2O ∏ H OH The OH ion is known as the hydroxide ion. The free H ion can react with another water molecule, as shown in the equation below. H H2O ∏ H3O The H3O ion is known as the hydronium ion. Acidity or alkalin- ity is a measure of the relative amounts of hydronium ions and hydroxide ions dissolved in a solution. If the number of hydronium ions in a solution equals the number of hydroxide ions, the solution is said to be neutral. Pure water contains equal numbers of hydro- nium ions and hydroxide ions and is therefore a neutral solution. Acids If the number of hydronium ions in a solution is greater than the number of hydroxide ions, the solution is an acid. For example, when hydrogen chloride gas, HCl, is dissolved in water, its mol- ecules dissociate to form hydrogen ions, H, and chloride ions, Cl, as is shown in the equation below. HCl ∏ H Cl These free hydrogen ions combine with water molecules to form hydronium ions, H3O. This aqueous solution contains many more hydronium ions than it does hydroxide ions, making it an acidic solution. Acids tend to have a sour taste; how- ever, never taste a substance to test it for acidity. In concentrated forms, they are highly corrosive to some materials, as you can see in Figure 2-13. Bases If sodium hydroxide, NaOH, a solid, is dissolved in water, it dissociates to form sodium ions, Na, and hydroxide ions, OH, as shown in the equation below. NaOH ∏ Na OH Copyright © by Holt, Rinehart and Winston. All rights reserved. Eco Connection onnection Acid Precipitation Acid precipitation, more commonly called acid rain, describes rain, snow, sleet, or fog that contains high levels of sulfuric and nitric acids. These acids form when sulfur dioxide gas, SO2, and nitrogen oxide gas, NO, react with water in the atmosphere to produce sulfuric acid, H2SO4, and nitric acid, HNO3. Acid precipitation makes soil and bodies of water, such as lakes, more acidic than normal. These high acid levels can harm plant and animal life directly. A high level of acid in a lake may kill mollusks, fish, and amphibians. Even in a lake that does not have a very elevated level of acid, acid precipitation may leach aluminum and magnesium from soils, poisoning water- dwelling species. Reducing fossil-fuel consump- tion, such as occurs in gasoline engines and coal-burning power plants, should reduce high acid levels in precipitation. Sulfur dioxide, SO2, which is produced when fossil fuels are burned, reacts with water in the atmosphere to produce acid precipitation. Acid precipitation, or acid rain, can make lakes and rivers too acidic to support life and can even corrode stone, such as the face of this statue. FIGURE 2-13 44 CHAPTER 2 This solution then contains more hydroxide ions than hydronium ions and is therefore defined as a base. The adjective alkaline refers to bases. Bases have a bitter taste; however, never taste a substance to test for alkalinity. They tend to feel slippery because the OH ions react with the oil on our skin to form a soap. In fact, commercial soap is the product of a reaction between a base and a fat. pH Scientists have developed a scale for comparing the relative con- centrations of hydronium ions and hydroxide ions in a solution. This scale is called the pH scale, and it ranges from 0 to 14, as shown in Figure 2-14. A solution with a pH of 0 is very acidic, a solution with a pH of 7 is neutral, and a solution with a pH of 14 is very basic. A solution’s pH is measured on a logarithmic scale. That is, the change of one pH unit reflects a 10-fold change in the acidity or alkalinity. For example, urine has 10 times the H3O ions at a pH of 6 than water does at a pH of 7. Vinegar, has 1,000 times more H3O ions at a pH of 3 than urine at a pH of 6, and 10,000 times more H3O ions than water at a pH of 7. The pH of a solution can be measured with litmus paper or with some other chemical indicator that changes color at various pH levels. Buffers The control of pH is important for living systems. Enzymes can function only within a very narrow pH range. The control of pH in organisms is often accomplished with buffers. Buffers are chemi- cal substances that neutralize small amounts of either an acid or a base added to a solution. As Figure 2-14 shows, the composition of your internal environment—in terms of acidity and alkalinity— varies greatly. Some of your body fluids, such as stomach acid and urine, are acidic. Others, such as intestinal fluid and blood, are

1. The following are ingredients in preparing pumping solution, EXCEPT; a. 5 kgs ham leg c. 1 cup saturated salt solution b. one tablespoon sugar d. 2 drops maplein 2. What is the value in grams of 6.4% refined salt if the amount of pork meat is 1 kilogram? a. 64 grams c. 640 grams b. 6.4 kilograms d. 6,400 grams 3. What is the main purpose of curing meat? a. To tenderize it c. To add color to it b. To prevent spoilage d. To increase its weight 4. What is the advantage of using pumping pickle over cover pickle and dry cure mixtures? a. It reduces the curing time. b. It enhances the flavor. c. It controls the concentration of salt. d. All of the above 5. What is the function of phosphate in curing solutions? a. It increases the water-holding capacity of the meat. b. It inhibits the growth of bacteria. c. It prevents oxidation of fat. d. It improves the texture of the meat. 6. What is the function of carrageenan in curing solutions? a. It acts as a thickener. b. It acts as a binder. c. It acts as a stabilizer. d. All of the above 7. In coloring salted eggs, how many teaspoons of vinegar must be added? a. 1 teaspoon b. 2 teaspoons c. 3 teaspoons d. 4 teaspoons 8. The following are factors that must be considered in packaging eggs. a. quality maintenance b. packaging design c. type of transport d. cost 9. In type 3 packaging material for eggs, what type of materials can these be made? a. burlap b. plastic c. paper board d. polystyrene 10. How many hours must be needed to bake the ham in an oven? a. 5 hours b. 3 hours c. 4 hours d. 2 hours 11. What is the ideal temperature of a smoke fish when storing it at home inside a refrigerator? a. 30℃ b. 38 ℃ c. 100 ℃ d. 50 ℃ 12. The following are ingredients for curing meat EXCEPT a. salt b. sugar c. vinegar d. cooking oil 13. What is the maximum period for commercial salted duck eggs? a. 18 days b. 21 days c. 14 days d. 30 days 14. What type of curing method is needed when fatty fish such as herring is being used? a. pickle curing b. dry curing c. cover pickle curing d. Pumping pickle curing 15. In making a pork ham, how many quarts of water must be needed to bring it to a boil? a. 2 quarts b. 3 quarts c. 4 quarts d. 5 quarts 16. In making a homemade skinless pork longganisa, what is the percentage of pork fats and lean meat? a. 20% fats, 80% lean meat b. 30% fats, 70% lean meat c. 40% fats, 60 lean meat d. 50% fats, 50% lean meat 17. It is a systematic procedure of producing a record for reference A. output C. documentation B. production report D. input 18. Anything produced, especially through a process, a product, a yield. A. documentation C. output B. input D. production report 19. It is the process of capturing data or translating information to a recording format. A. documentation C. production report B. reporting D. output 20. What is the value in grams of 6.4% refined salt if the amount of pork meat is 1 kilogram? a. 64 grams c. 640 grams b. 6.4 kilograms d. 6,400 grams 21. What is the difference between pumping pickle and cover pickle? a. Pumping pickle is injected into the meat, while cover pickle is poured over it. b. Pumping pickle is made with vinegar, while cover pickle is made with water. c. Pumping pickle is used for whole cuts of meat, while cover pickle is used for sliced meat. d. Pumping pickle is a dry mixture, while cover pickle is a liquid solution. 22. What is the main ingredient of dry cure mixtures? a. Sugar b. Salt c. Spices d. Phosphate 23. What is the function of vitamin C powder in curing solutions? a. It acts as an antioxidant. b. It enhances the color of the meat. c. It accelerates the curing reaction. d. All of the above 24. What is the ideal temperature for storing cured meat? a. Below 0°C b. Between 0°C and 4°C c. Between 4°C and 10°C d. Above 10°C 25. The following are advantages of packaging shell eggs EXCEPT. a. It protects against micro-organisms such as bacteria b. It prevents the loss of moisture. c. It protects the eggs from possible crushing while being handled, stored, or transported. d. It prolong the shelf life of the eggs. 26. How many pieces of eggs can be filled in a type 2 packaging materials, filler tray? a. 36 b. 12 c. 30 d. 24 27. How many hours must be needed in smoking ham? a. 10 to 19 hours b. 5 to 9 hours c. 15 to 24 hours d. 20 to 29 hours 28. It is a food packaging method that removes all air from a food-filled, plastic film package before sealing it. a. smoking b. drying c. vacuum packing d. weighing 29. Which is NOT TRUE about packaging a smoked fish? a. Sort cooled smoked fish according to size b. Pack or transfer smoked fish in bulk packaging materials by arranging the fish head and tail in any position. c. When the packaging material is nearly full, weigh the whole pack to check the product weight attained. d. Close or seal the packs. 30. The following nutrients can be found in an egg, EXCEPT. a. vitamins b. minerals c. omega 3 d. amino acids

Many of water’s biological functions stem from its chemical struc- ture. Recall that in the water molecule, H2O, the hydrogen and oxygen atoms share electrons to form covalent bonds. However, these atoms do not share the electrons equally. The oxygen atom has a greater ability to attract electrons to it because it pulls hydrogen’s electrons towards its nucleus. As a result, as shown in Figure 2-8, the region of the molecule where the oxygen atom is located has a partial negative charge, denoted with a , while the regions of the molecule where each of the two hydrogen atoms are located have partial positive charges, each of which are denoted with a . Thus, even though the total charge on a water molecule is neutral, the charge is unevenly distributed across the water molecule. Because of this uneven distribution of charge, water is called a polar compound. Notice also in Figure 2-8 that the three atoms in a water mole- cule are not arranged in a straight line as you might expect. Rather, the two hydrogen atoms bond with the single oxygen atom at an angle. SECTION 3 OBJECTIVES ● Describe the structure of a water molecule. ● Explain how water’s polar nature affects its ability to dissolve substances. ● Outline the relationship between hydrogen bonding and the different properties of water. ● Identify the roles of solutes and solvents in solutions. ● Differentiate between acids and bases. VOCABULARY polar hydrogen bond cohesion adhesion capillarity solution solute solvent concentration saturated solution aqueous solution hydroxide ion hydronium ion acid base pH scale buffer Copyright © by Holt, Rinehart and Winston. All rights reserved. (a) Electron cloud model (b) Space-filling model H H O The oxygen region of the water molecule is weakly negative, and the hydrogen regions are weakly positive. Notice the different ways to represent water, H2O. You are familiar with the electron cloud model (a). The space- filling model (b) shows the three- dimensional structure of a molecule. FIGURE 2-8 40 CHAPTER 2 Hydrogen bond H H H H H H H H H O O O O O O H H H H H – – – – – – – + + + + + + + + + + + + + + The dotted lines in this figure represent hydrogen bonds. A hydrogen bond is a force of attraction between a hydrogen atom in one molecule and a negatively charged region or atom in a second molecule. FIGURE 2-10 The positive region of a water molecule attracts the negative region of an ionic compound, such as the Cl portion of NaCl. Similarly, the negative region of the water molecule attracts the positive region of the compound—the Na portion of NaCl. As a result, NaCl breaks apart, or dissolves, in water. FIGURE 2-9 CI– Na+ H2O + + – – Solubility of Water The polar nature of water allows it to dissolve polar substances, such as sugars, ionic compounds, and some proteins. Water does not dissolve nonpolar substances, such as oil because a weaker attraction exists between polar and nonpolar molecules than between two polar molecules. Figure 2-9 shows how water dissolves the ionic compound sodium chloride, NaCl. In your body, ions, such as sodium and chloride, are essential to bodily func- tions, such as muscle contraction and transmission of impulses in the nervous system. In fact, dissolved, or dissociated ions, are pre- sent in all of the aqueous solutions found in living things and are important in maintaining normal body functions. HYDROGEN BONDING The polar nature of water also causes water molecules to be attracted to one another. As is shown in Figure 2-10, the positively charged region of one water molecule is attracted to the negatively charged region of another water molecule. This attraction is called a hydrogen bond. A hydrogen bond is the force of attraction between a hydrogen molecule with a partial positive charge and another atom or molecule with a partial or full negative charge. Hydrogen bonds in water exert an attractive force strong enough so that water “clings” to itself and some other substances. Hydrogen bonds form, break, and reform with great frequency. However, at any one time, a great number of water molecules are bonded together. The number of hydrogen bonds that exist depends on the state that water is in. If water is in its solid state all its water molecules are hydrogen bonded and do not break. As water liquifies, more hydrogen bonds are broken than are formed, until an equal number of bonds are formed and broken. Hydrogen bonding accounts for the unique properties of water, some of which we will examine further. These properties include cohesion and adhesion, the ability of water to absorb a relatively large amount of energy as heat, the ability of water to cool surfaces through evaporation, the density of ice, and the ability of water to dissolve many substances.

Solution: A liquid where something has been dissolved (like salt in water). Saturated Solution: A solution where no more of a substance can dissolve. Acid: A substance that can react with other substances, often sour in taste (like grape juice). Alkaline/Base: A substance that can neutralize acids (like baking soda). pH: A scale used to measure how acidic or alkaline something is.

Mitigation and Adaptation. The Philippines is situated in a disaster risk area where hazards will always be present. The government's response to mitigate and adapt to these hazards is through the creation of hazard maps. Hazard maps are developed to indicate the places where most natural hazards occur or will most likely occur. Identifying these places can aid in informed land-use and the persons-in-charge can create emergency response plans. With the proper knowledge of hazards and the actions to be taken if ever they occur will help in the reduction and mitigation of the dangers of these natural hazards to life and property. In the Philippines, the Department of Environment and Natural Resources (DENR) created a Geohazard Mapping and Assessment Program implemented by the Mines and Geosciences Bureau, which identifies areas vulnerable to geologic hazards or geohazard. They are also responsible for developing the hazard maps. High susceptibility to landslide. • Areas with high susceptibility rating have active/recent landslides and tension cracks that would directly affect the community. Those with steep slopes and drainages that are prone to landslide damming are also highly susceptible to landslides. Moderate susceptibility to landslide. • Areas with moderate landslide susceptibility rating have inactive/old landslide and tension cracks which are located away from the community. These areas usually have moderate slopes. Low susceptibility to landslide . • Areas with low to gentle slopes and lacking tension cracks have low landslide susceptibility rating. High susceptibility to flooding . • Areas with greater than 1-meter flood height. These areas are usually flooded for several hours during heavy rains include landforms of topographic lows such as active river channels, abandoned river channels and areas along river banks; also prone to flashfloods. Low to moderate susceptibility to flooding. • Areas with less than 10-meter flood height. These are usually inundated during prolonged and extensive heavy rainfall or extreme condition. Aside from the development of hazard maps, action plans should be conceptualized to identify the priorities for action and plan for the possible impacts affecting the country. Local programs should be established to help the people who are most affected by natural disasters to recover from their losses. Such programs can include training the people to innovate and think out of the box to come up with ideas or solutions that will be more effective for their livelihood. Education is also a means for people to mitigate and adapt to natural hazards. It can increase mass awareness regarding natural hazards; thus, increasing their chances of survival. It is also a means of promoting access to information and resources that will help individuals be better prepared for natural hazards. Lastly, formal education can empower individuals to be more adaptive with their responses to and recovery from natural hazards. In preparation for natural hazards, information regarding what to do before during, and after a natural hazard is disseminated all over the country. The following are the things to do to be prepared for each natural hazard..

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