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Welcome! The Topic For Today Is…STE Sec 4. Your Topic. Topic 1: 200. Question: What is the difference between a toxic and a lethal dose? What year did the Great Depression begin Answer
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Welcome! The Topic For Today Is…STE Sec 4
Topic 1: 200 • Question: • What is the difference between a toxic and a lethal dose? • What year did the Great Depression begin • Answer • A toxic dose is the amount in mg of substance per kg of weight that causes illness. A lethal dose is the concentration that kills. Back
Topic 1: 400 • Question: • Calculate the LD50 in each of the following cases. Express in mg/kg. • A dose of 1500 mg of salt killed 50% of 5000 g rabbits. • Answer • 1500 mg/5 kg = 300 mg/kg Back
Topic 1: 600 • Question: • A 75 kg man was killed because in drinking 1000g of booze, he experienced a LD50 for alcohol. The booze was 53% alcohol. • Answer • 0.53*1000 000 mg/75kg • = 7066 mg/kg Back
Topic 1: 800 • Question: • How many 500 mg vitamin tablets would a 100 kg patient have to swallow inorder to experience a lethal dose if the LD50 is 11.9 g/kg? • Answer • 11.9 g/kg * 100 kg = 1190 g 1190g/ 0.5 g/tablet = 2380 tablets Back
Topic 1: 1000 • Question: • A certain type of green algae have a cadmium concentration of 0.10 parts per million. But an analysis of the algae reveals that the concentration of cadmium contaminant in the water is 0.01 ppm. Calculate the BCF factor. • Answer • 0.10/0.01 = 10 Back
Topic 2: 200 • Question: • What ion formed from an element of the fourth shell (4th period) is found in seashells? • Answer • Ca+2 Back
Topic 2: 400 • Question: • Describe an experiment that you could do to help you prove that a hydrogen ion does not have the same chemical properties as a neutral hydrogen molecule • Answer • Add blue litmus to acid(has hydrogen ion). The litmus will turn red. • Place blue litmus in hydrogen gas. Nothing will occur. Back
Topic 2: 600 • Question: • Explain why +1 is the common ion for alkali metals. • Answer • They all have 1 loose valence electron. Back
Topic 2: 800 • Question: • I am an element that likes to form the -1 ion, and I have the smallest nucleus among the members of my family. What am I? • Answer • Fluoride Back
Topic 2: 1000 • Question: • Explain why fluorine forms diatomic molecules. • Answer • By having 9 protons but only two shells, each F nucleus has enough force to pull in an electron from the other. The result is that the shared electrons act as a bond. Back
Topic 3: 200 • Question: • Convert the following: • 300 g of Mg = __________moles • Answer • 300 g (mole/24 g) = 12.5 moles Back
Topic 3: 400 • Question: • Convert the following • 6 moles of O2 = ________molecules • Answer • 6 moles (6.02 X 1023 molecules/mole) = • 3.6 X 1024 molecules Back
Topic 3: 600 • Question: • Monty Mole found a mole of gold. If goldsells for $28 US per gram in Dec 2008, what is the value of Monty’s mole of gold? • Answer • 1 mole Au = 197 g • 197 g($28/g) = $ • 5516 US Back
Topic 3: 800 • Question: • How many moles of water will be produced if 5 moles of ammonia, NH3(g), react • Answer • 5 moles NH3 (6 H2O/ 4 NH3(g)) ) =7.5 molesH2O Back
Topic 3: 1000 • Question: • How many grams of oxygen react with every 1.0 gram of NH3(g)? • Answer • 0.074 moles O2 (32 g/mole) = 2.35 g O Back
Topic 4: 200 • Question: • An average sized banana (118 g) yields 454.300 kJ of heat when burnt to a crisp. • If you managed to transfer all of the heat to a cup of water ( 250 g) at 20 oC, how warm would the water get? • Answer • Specific heat of water = 4190 J (kg C) or 4.19 J (g C) • Q = mcT • 454 300 J = 250 g(4.19 J/(g oC)(x – 20) • x = 454 oC • (That temperaturewillneverbeobtained for water---it’llboil off first, whichmeansthat a cup of water istoosmall to absorb all the heat.) Back
Topic 4: 400 • Question: • You want to cool 1000 kg of water at 40o C to a comfortable 32o C with only 258 L of water. How cold should that 258 L be, assuming that no heat is lost to the surroundings ? • Answer • Density of water: 1.0 kg/L • -Qhot = Qcold • -1 000 000(4.19)(32-40) = 258 000(4.19)(32-x) • -1000(-8) = 258(32 - x) • 8000/258 = 32 – x • x = 32 -8000/258 x= 1oC Back
Topic 4: 600 • Question: • How much energy in joules is used by the heating element of the coffee maker during this period? • Answer • E = VIt • V=IR, so I =V/R=120/20 • = 120 J/C(120/20)C/s(15*60 s) • = 648 000 J Back
Topic 4: 800 • Question: • A series circuit with three light bulbs has voltage drops of 1.2 V, 1.4 V and 1.4 V. The ammeter measures 0.50 A. • What is the wattage of the bulb that consumes the least energy? • Answer • P = VI = 1.2J/C(0.50 C/s) = 0.6 J/s = 0. 6 W. Back
Topic 4: 1000 • Question: • A series circuit with three light bulbs has voltage drops of 1.2 V, 1.4 V and 1.4 V. The ammeter measures 0.50 A. • How much energy is used by all three bulbs every hour they’re turned on? • Answer • Vt= 1.2+1.4+1.4= 4.0 V • E = VIt=4(0.5)(3600 s) = 7200 J Back
Topic 5: 200 • Question: • The effective force is in the direction of the acceleration. If the 35 N force is applied at angle of 27o, calculate the effective force. • Answer • Feffective/35 = cos 27 • Feffective= 35 cos 27 = 31.2 N Back
Topic 5: 400 • Question: • The effective force is in the direction of the acceleration. If the 35 N force is applied at angle of 27o, calculate the effective force. • What is the vertical component of the 35 N force? • Answer • Feffective/35 = sin 27 • Feffective= 35 sin 27 = 15.9 N Back
Topic 5: 600 • Question: • The effective force is in the direction of the acceleration. If the 35 N force is applied at angle of 27o, calculate the effective force. • Find the combined weight of the girl and the sled if the combined mass is 30 kg. • Answer • Weight =Fg= mg • =(30 kg)(9.8m/s2)= 294 N Back
Topic 5: 800 • Question: • The effective force is in the direction of the acceleration. If the 35 N force is applied at angle of 27o, calculate the effective force. • Why doesn’t the sled lift up? • Answer • 294 N > 15.9 N(the vertical component) Back
Topic 5: 1000 • Question: • Calculate the skier’s effective force • as he is pulled downhill. • Answer • sin Feffective/Fg2 • sin 12 = Feffective/(75 kg*9.8m/s ) Feffective=75 kg*9.8m/s2)sin12 • =152.8 N Back
Daily Double The Winner Of The Last Round Write Down How Much Money You Are Willing To Risk If You get the Question write you win that money If you get it wrong you Loss the money!
Daily Double The Winner Of The Last Round Write Down How Much Money You Are Willing To Risk If You get the Question write you win that money If you get it wrong you Loss the money!