Dr Khounsary explains an experiment using a fixed voltage and varying the temperature of the wire using a torch. The article further explains that the temperature coefficient of copper at 20 degrees C is .00393 and that a single degree of temperature change would increase the resistance of the wire by that amount. In the article regarding the Effect of Temperature on Conductivity (The Nuffield Foundation, 2006) the article describes how the conductivity of a wire decreases as it is heated. It provides an example schematic diagram for the test circuit and the use of Eureka wire instead of copper wire. A2a.
(2 points) Mg(s) + 2 HCl(aq) → H2(g) + MgCl2(aq) 2. Determine the partial pressure of the hydrogen gas collected in the gas collection tube. (3 points) partial pressure H2 = total pressure - vapor pressure of water = 746mmHg - 19.8mmHg = 726mmHg 3. Calculate the moles of hydrogen gas collected. (4 points) n = 125 4.
What did Boyle’s experiments convince him about cold? That heat is a form of motion of a particular kind as bodies cool down the particles move less and less 5. How did Boyle explain that substances expand when they warm up? He thought back to his air experiments, and explained that the particles have spring like coils that expand as they heat 6. Describe the earliest alcohol thermometers.
If the reaction is first order, its graphical representation is seen as ln[A] (natural log of concentration) vs. time, and the slope of its like is also the negative rate constant. Finally, for a second order reaction the graph is shown as 1/[A] (inverse of concentration) vs. time, and the slope of its given line is the positive rate constant. By understanding the rate law and finding the value of the correct rate constant with respect to the order of the reaction, one can determine the half-life of the crystal violet. This is because the crystal violet undergoes a decay reaction with the sodium hydroxide. According to Beer's Law, the absorbance of crystal violet is proportional to its concentration.
(4 points) q = m × c × Δt Given: q=? m = 34.720g c = 4.18 j/(g x °C) Δt = 41.6°C - 25.2°C = 16.4°C q = (34.720g) (4.18 j/(g x °C) (16.4°C) q = 2380.13j You are trying to figure out the energy change of the water which is the surroundings in the lab. To do that you must take the mass of the metal, which for me was Aluminum, and multiply it by the heat capacity of the water, which was given, then multiply that by the change in temperature, which is the final temperature of the mixture
Fully simplify the expression, tanx1+ tan2x . Use the knowledge that sin x= -35 and π2≤x ≤ 3π2 to express your simplified expression as an exact answer in fraction form. 4 Heat loss from electric hot water systems is an environmental issue. It is recognised that the heat loss from a closed, full hot water tank is proportional to the surface area of the tank. Determine the ratio of the heat loss from a 1m3 cylindrical tank of optimum dimensions (that is, the dimensions of the cylindrical tank for which the heat loss is a minimum) to the heat loss from a cubic tank with the same volume.
Therefore the reacted Zn = initial mass – excess mass. 3. What is the color change observed upon heating and why is this important? 4. Know how to come up with the simplest chemical formula from the mole ratio.
If the water in this experiment did not boil at 100°C, what could be the reason? a. Atmospheric pressure takes effect with the higher sea levels, causing the water to boil at a lower temperature. B) While heating two different samples of water at sea level, one boils at 102°C and one boils at 99.2oC. Calculate the percent error for each sample from the theoretical 100.0°C. a.
4) When naming an ionic compound, which ion is given first? The metal ion is named first 5) Give explanations for the following: a. Argon will not react with any other element It already has a complete number of eight, a full number in its valance shell so it cannot react with itself or another element b. The reaction between sodium chloride gives out a lot of heat and light. The chemical energy of the product is less then the chemical energy of the reactants. This energy is indestructible and is converted to light and heat.
This creates an atomic-level "friction" which produces heat (and light in some cases, such as a light bulb or glowing heater element). The important thing to remember is that an electron does not need to travel all the way through a wire for a device on the other end to receive power. When you turn on the tap to fill a glass, the water company doesn't have to pump a glassful of water from their facility all the way to your house - there is already water in the pipe, and they just need to add a little more on their end for some to come out your tap. If some electrons are pushed into one end of the wire, some will come out the other end because the uncharged metal in the wire already contains a sea of electrons(Matt Kramer of Wisconsin). For example, a circuit board has wires on