Begin a preliminary design of a simple, 4-cylinder, naturally aspirated, spark-ignition engine based on an ideal otto cycle. the engine should operate on e30 fuel (assume 30% ethanol, c2h6o and 70% iso-octane, c8h18 on a volume basis, rhoethanol = 790 kg/m3 , rhoiso-octane = 692 kg/m3 ) and less than 5% excess air (to avoid emissions aftertreatment issues). the engine should develop a power of 75 kw under full load at 3500 rpm (remember this is a 4- cylinder engine using a 4-stroke cycle). assume port fuel injection, such that the intake charge contains a fuel/air mixture at 30 °c and 1 bar (state 1). spark is triggered at the end of an isentropic compression stroke (state 2), followed by infinitely fast combustion (state 3). to avoid knock under boosted conditions, your compression ratio cannot be greater than 13: 1. also, consider that most si engines have comparable bore and stroke sizes, but you are free to decide the bore to stroke ratio, β.

Which process transfers heat from inside earth to its surface? convection currents in mantle pulling away of tectonic plates drawing in of tectonic plates convection currents in crust

Experiment: effect of solution concentration on reaction rate you have learned that as the concentration of reactants increases, there will most likely be a greater number of collisions, and hence increase the rate of a reaction. in this experiment, you will see a demonstration of this, with a twist. there will be three reactions going on in this experiment. objectives determine how solution concentration can affect the rate of a reaction. the first reaction will be a reaction of the iodide ion (i-1) with hydrogen peroxide (h2o2) in an acidic solution. this reaction produces a slightly orange solution. in our experiment, we will add some orange food coloring to make this solution more orange. 2 h+ (aq) + 2 i- (aq) + h2o2 (aq) ⟶ i2 (aq) + 2 h2o (l) the next reaction will be between the iodine and starch i2 + starch ⟶ i2-starch complex (blue-black) so, when starch is added to the iodine solution made from the first reaction, the solution will turn black immediately, so it is difficult to find the rate of reaction. in order to be able to time this reaction, you will slow it down with another reaction. adding ascorbic acid will react with the iodine, reducing the concentration of the iodine available to react with the starch. c6h8o6 (aq) + i2 (aq) ⟶ 2i- (aq) + c6h6o6 (aq) + 2 h+ (aq) when the ascorbic acid is used up, the remaining iodine molecules can react with the starch and form the black color. the more ascorbic acid you add, the slower the reaction to form the iodine-starch complex will be. use your data and observations to complete the assignment. analysis and conclusions submit your data and the answers to these questions in the essay box below. what was your hypothesis? plot your data as drops of ascorbic acid vs. time. as the concentration of ascorbic acid was increased, did the rate of the formation of the iodine-starch complex increase or decrease? explain your answer in terms of the chemical reactions involved. was your hypothesis correct? make a general rule about the effects of concentration of reactants on reaction rates. for practice, the molecular formula for ascorbic acid is c6h8o6, and you used 6 g in this experiment, calculate the molarity of the ascorbic acid. now calculate the concentration in moles per drop (assume 1 ml = 20 drops).

While in europe, if you drive 125 km per day, how much money would you spend on gas in one week if gas costs 1.10 euros per liter and your car’s gas mileage is 32.0 mi/gal? assume that 1 euro=1.26 dollars