Hi! Can you please check if my answers are correct? And, can you please tell me any other details you think are important to add. Also, the last two questions i have no clue how to answer. can you help? thanks so much!
3.A burning candle produces a luminous flame. What is the fuel for the burning candle? Why is the flame luminous?
- The fuel for the burning candle is oxygen. With an insufficient supply of oxygen, small carbon particles are produced, which, when heated to incandescence, produce a yellow, luminous flame. The combustion products may, in addition to carbon dioxide and water, include carbon monoxide.
4. Part C. 1c. The solid is not completely submerged in the water. Will this technique error increase, decrease, or have no effect on the reported density of the solid? Explain.
- If the solid is not completely submerged in the water, the reported density would increase. The volume would be less than it is supposed to be, and so the density would be greater than the correct reading.
5. Part C.2. Suppose that after delivery several drops of the water cling to the inner wall of the pipet (because the pipet wall is dirty). Will this technique error increase, decrease, or have no effect on the reported density of water? Explain.
- If several drops of water cling to the inner wall of the pipet, the volume of the water would be a lower value then what the pipet was calibrated to. So, the density of the water would be increased. The mass that you are weighting will be greater than it should be, which gives you a greater density.
6.Part C.3. The unknown liquid is volatile. If some of the liquid evaporates between the time the liquid is delivered to the beaker and the time its mass is measured, will the reported density of the liquid be too high, too low, or unaffected? Explain.
- The formula for density is: mass/volume. Volume is not affected since the beaker is not expanding nor shrinking. Since some of the liquid evaporated between the time the liquid was delivered to the beaker to the time the mass was measured, the mass measures are less. As a result, the reported density of the liquid would have an outcome lower than expected.
1. Part A.1. If you have a properly adjusted hot flame, which is pale blue with three distinct cones, what is observed if the gas control valve is slightly closed? Explain.
2. Part A.1. If you have a properly adjusted hot flame, which is pale blue with three distinct cones, what is observed if the air-control valve is slightly closed? Explain.
3A. The fuel is the candle wax. The rest of the answer is ok.
4 is ok.
5. I can't be sure what you did but from your answer I have assumed you measured a liquid with a pipet, dispensed into a container, WEIGHED the liquid from the pipet and calculated the density from that. If that is right, then I don't agree with the answer. As far as your experiment is concerned, you dispensed the volume OF THE PIPET (even though not all of came out of the pipet). Then you weighed the liquid dispensed and that weighs less since less is present. d = m/v; mass is less, volume is the labeled volume of the pipet so density is less.
6 is ok.
For the two questions at the end, I suggest you do this in the lab and you will know the answer.
1. If the gas control valve is slightly closed, the flame will begin to struggle and flicker like a scared cat trying to escape a bath. It may even go out completely, leaving you in the dark and feeling a little blue yourself. So, make sure to keep that valve open and let the flame shine!
2. If the air-control valve is slightly closed, the flame will become lazy and lethargic, like a sloth on a rainy day. It will lose its pale blue color and turn into a lazy yellow flame, giving off less heat and making you wonder if it's on vacation. So, don't be a party pooper and keep that valve open for a lively and hot flame!
1. If the gas control valve is slightly closed when you have a properly adjusted hot flame, the flame will become smaller and less intense. This is because the flow of gas is restricted, resulting in a decrease in the fuel supply to the flame. The flame may also change color, becoming more yellow or orange. This occurs because the incomplete combustion of the fuel produces carbon particles, which glow and emit light, causing the flame to appear yellow or luminous.
2. If the air-control valve is slightly closed when you have a properly adjusted hot flame, the flame will become more yellow and sooty. This is because the air supply to the flame is reduced, leading to incomplete combustion. The incomplete combustion results in the formation of carbon particles, which do not burn completely and create soot. The soot particles emit light and give the flame a yellow color. The reduced air supply may also cause the flame to become less stable and flicker. It is important to have the correct balance of fuel and air to maintain a pale blue flame with three distinct cones, which signifies that complete combustion is occurring.
1. If the gas control valve is slightly closed while you have a properly adjusted hot flame, which is pale blue with three distinct cones, the flame would start to become smaller and weaker. This is because the gas flow is being restricted, resulting in less fuel being supplied to the flame. As a result, the temperature of the flame would decrease, and the color of the flame may shift towards a darker blue or even yellow. The distinct cones may also become less defined.
2. If the air-control valve is slightly closed while you have a properly adjusted hot flame, which is pale blue with three distinct cones, the flame would also start to become smaller and weaker. This is because the closure of the air-control valve restricts the amount of oxygen available for combustion. Oxygen is necessary for a complete and efficient combustion process. With reduced oxygen supply, the flame would have insufficient oxygen to fully burn the fuel, resulting in a decrease in the flame's temperature. The color of the flame may shift towards a darker blue or even yellow, and the distinct cones may become less defined.