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Unformatted text preview: Problem Set 1 1 The following are metric numerical prefixes. Identify the exponent that corresponds to the scientific notation for each. Giga 10^ Mega 10^ Kilo 10^ Hecto 10^ Deca 10^ Deci 10^ Centi 10^ Milli 10^ Micro 10^ Nano 10^ Pico 2) The following are the diameters of 2 different cells. Mycoplasma Plant cell A) Calculate the surface area and the volume of both cells. (Help: SA=(4)(3.14)(r^2)=(3.14)(d^2), V=(4/3)(3.14)(r^3)=(4/3)(3.14)(d/2)^3) B) d=20nm(nanometers) d=50m(micrometers) 10^ Calculate the ratio of the diameter, surface areas, and of volumes between the 2 cells. (Mycoplasma/plant cell) Comment on your observations 3) Give a unique example of each of the following characteristics of life. Are any of these characteristics evident in nonliving systems? Order Evolutionary adaptaion Response to environment Reproduction Growth and Development Energy processing Regulation 4) An atom is a basic unit of matter consisting of a dense central nucleus surrounded by a cloud of negatively charged electrons. A) What are the 2 subatomic particles discussed in class that make up the nucleus? B) List a similarity and a difference mentioned in class between these 2 particles. C) These particles determine both the atomic number and the mass number. What does each number mean and how is each determined. D) Imagine that you have 2 different particles. If they have different atomic number, what does this mean? If they have different mass number what does this mean? What does it mean if they have the same atomic number and different mass numbers? What does it mean if they have the same mass number and different atomic numbers? 5) A) Identify each of the following 2 letter elemental abbreviations. O C H N Ca P K S Na Cl Mg B) An atomic ion is an atom with a different count of protons and electrons. For each of the above elements indicate the charge of its most likely monoatomic ion. 6) A) The elements in the first 2 columns in the periodic table of elements are metals, and the elements in the top right portion of the periodic table are nonmetals. Is there a trend between ionic charge and whether it is a metal or nonmetal? B) Suggest a possible explanation for the observed trend. 7) Interatomic and intermolecular interactions were discussed in class. List the 4 mentioned in order of decreasing strength. 8) A) A molecule consists of 2 or more atoms that are covalently bonded. Draw the following molecules(Lewis Dot). Make sure to indicate what electrons are being shared. (Hint: All of the following molecules are neutral, what does this tell you about the number of electrons?) O2 H2O CO2 CH4 B) Label all polar covalent bonds in the above molecules 9) A) Ionic interactions play a large role in biology. Give 4 examples of an ionic compound. B) These ionic compounds are also called salts. Salts do not have to be composed of inorganic monoatomic cations and anions. Give 3 examples of salts that have at least one polyatomic ion. 10) A chemical reaction is a process that leads to the transformation of one set of chemical substances to another. R) In the following Identify which compounds are molecules A) __N2 + __H2 __NH3 B) __H2O+__CO2 __C6H12O6+__O2 C) __Na(s)+__HCl(aq) __NaCl(aq)+__H2(g) 11) A salt is also defined in chemistry as an ionic compound that can result from the neutralization reaction of acids and bases. In its most basic form, an acid can be defined as any substance that increases hydrogen ion (actually hydronium ion) concentration. i.e. HCl H++Cl Similarly a base can be described as any substance that reduces hydrogen ion concentration of a solution.i.e. NaOH +H+ Na+ +OH+H+ Na++H2O S) Suppose that you have 500mL of 1 M HCl, and .75M NaOH. What is the initial pH of each? What is the concentration of OH and of the H+? identify which compounds are ionic compounds balance each equation 12) A buffer is a solution which reduces the change in pH upon addition of small amounts of acid or base, or upon dilution. Why are buffers critical to biological systems? 13) The four emergent properties of water discussed in class are 1) cohesion 2) moderation of temperature; a)high specific heat, b)evaporative cooling 3) insulation by floating ice 4) solvent properties Identify each of the following observations in nature with one of the above emergent properties of water. Water reaches the tip of a giant red wood tree 100m tall without any pumps or any mechanical forces. Small bugs can walk on water. Local temperature around the great lakes, and in coastal areas is cooler during the summer and warmer during the winter. Water on the bottom of lakes in Russia does not freeze even with cold winds blowing less than 20 degrees celcius. Dogs panting on hot days. A can of rockstar energy drink has 12 tablespoons of delicious sugar, but you do not see a single sugar crystal as you drink it. Water spots on your car after it rains. 14) Although cells are 7095% water, life on earth is termed "Carbon based." Most of the 530% that is not water is composed of carbon based compounds. Carbon can almost always make 4 bonds. Isomers are molecules with the same molecular formula (i.e. they have the same type and number of atoms) but have different structures and properties. Give one example of each of the following types of isomer and be sure to include a pictorial representation drawing attention to the difference that uniquely identifies each isomer. Try to do this without looking at your notes based on a carbon chain. Structural Geometric Enantiomer 15) Some biological molecules consist of thousands of atoms. They each have functional groups. A) What is a functional group? B) Draw each of the following functional groups Hydroxyl Carbonyl Carboxyl Amino Sulfhydryl Phosphate Methyl C) Try to identify some use or function in everyday life that is caused by the above functional groups. ...
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- Spring '09