Presentation on theme: "When you think of water, what comes to mind? (At least two full sentences, please.) Cuando piensas de agua, lo que viene a la mente? (at menos 2 lleno."— Presentation transcript:
When you think of water, what comes to mind? (At least two full sentences, please.) Cuando piensas de agua, lo que viene a la mente? (at menos 2 lleno frases, por favor.). Properties of water
Vocabulary Polar - the uneven spreading of positive and negative charges within a molecule Hydrogen bond - the force of attraction between a hydrogen atom and the negative charge of another molecule Cohesion - the force that causes molecules of the same substance to stick together (like water) adhesion - the force that causes the molecules of different substances to stick together Capillarity - the attractions of molecules which results in the rise of the surface of a liquid when it touches a solid surface
Vocabulary Substance - matter, stuff Molecule - atoms bonded together Charges - positive or negative electric position of a particle
Properties of water Review Questions: What is the charge of a proton? What is the charge of a neutron? What is the charge of an electron? How many hydrogen and oxygen atoms does a water molecule have? Which of the above particles are in the nucleus of an atom?
Properties of water Questions: What is hydrogen bonding?
Properties of water Questions: What is adhesion and cohesion? cohesion = water attracted to other water molecules adhesion = water attracted to other materials surface tension = water is pulled together creating the smallest surface area possible Cohesion, Adhesion and Surface Tension
Properties of Water Covalent bonding vs. Hydrogen bonding Covalent Bond Hydrogen Bond
Properties of Water What is capillary Action? Because water has both adhesive and cohesive properties, capillary action is present. Capillary Action = water’s adhesive property is the cause of capillary action. Water is attracted to some other material and then through cohesion, other water molecules move too as a result of the original adhesion. Ex: Think water in a straw Ex: Water moves through trees this way
Water is the solvent of Life! Solute – substance dissolved in a solvent to form a solution Solvent – fluid that dissolves solutes Example: Ice Tea – water is the solvent and tea and sugar the solutes What is a solvent and a solute? Properties of water
Properties of Water Density Water is less dense as a solid! This is because the hydrogen bonds are stable in ice – each molecule of water is bound to four of its neighbors. Solid – water molecules are bonded together – space between fixed Liquid – water molecules are constantly bonding and rebonding – space is always changing Questions: What is density?
Acids and Bases Strength compared using pH scale Ranges from 0 – 14 Logarithmic Scale (gets 10x bigger/smaller) Acid – donates H+ when added to aqueous solutions Ranges from pH 0-6.9 Base – breaks up into hydroxide (OH-) ions and another compound when placed in an aqueous solution Ranges from pH 7.1 – 14 Distilled water is pH 7.0 or neutral. Why? H 2 O H+ + OH- What is PH?
Properties of water Question: What is acid? What is base?
Properties of water What are some properties of Bases? taste bitter (don't taste them!) feel slippery or soapy (don't arbitrarily touch them!) bases don't change the color of litmus; they can turn red (acidified) litmus back to blue their aqueous (water) solutions conduct and electric current (are electrolytes) react with acids to form salts and water
Properties of water What are some properties of Acids? taste sour (don't taste them!)... the word 'acid' comes from the Latin acere, which means 'sour' acids change litmus (a blue vegetable dye) from blue to red their aqueous (water) solutions conduct electric current (are electrolytes) react with bases to form salts and water evolve hydrogen gas (H2) upon reaction with an active metal (such as alkali metals, alkaline earth metals, zinc, aluminum)