Answer:
Le Chatelier's principle can be applied in explaining the results
Explanation:
According to Le Chatelier's principle, when a constraint such as a change in concentration in this case is imposed on a chemical system in equilibrium, the system will adjust itself in such a way as to annul the constraint imposed.
Hence, when the color of the solution was more like that of the control, the reaction would shift towards the left. Similarly, when the color was more like it was towards the reactant, the reaction would shift towards the right.
If we were to prepare calcium oxalate, we should prepare it in a base solution. This is because when the base was added to calcium oxalate, it did not form any precipitate but when an acid was added to the calcium oxalate, it formed a precipitate.
Answer: 12.92g of CoSO4
Explanation:
Molar Mass of CoSO4 = 59 + 32 + (16x4) = 59 + 32 +64 = 155g/mol
Molarity of CoSO4 = 0.303mol/L
Mass conc. In g/L = Molarity x molar Mass
= 0.303x155 = 46.965g/L
275 grams of water = 0.275L of water
46.965g of CoSO4 dissolves in 1L
Therefore Xg of CoSO4 will dissolve in 0.275L i.e
Xg of CoSO4 = 46.965x0.275 = 12.92g
Therefore 12.92g of CoSO4 is needed
Here I found some info at Yahoo answers: https://answers.yahoo.com/question/index?qid=20090119191941AAB7oAb
The more electronegative an atom is the more unwilling it is to lose its electrons in a compound. If you do try to take a very EN atom away from a compound you'll need to apply a lot of energy for that to happen. I can give an example of a single atom though
<span>Cl has 7 valence electron filled and every atom wants to be like nobles (noble gases), so it's not going to give an electron away b/c it's really close to being like a noble gas. Noble gases are the most stable atoms, which is why I say stability counts.</span>
<span>The answer to question 2 is C. A magnifying glass is an example of a plano-convex lens, where one side of the lens is flat and the other is a convex curve. The answer to question 3 is either B or C. A converging lens is curved on both sides and so the rays of light coming out of it converge at a point, which is known as the focal point. When the object is inside the focal point, the image is real and inverted. If it is inside the focal point, the image is virtual and upright. Therefore the image in this question will be upright. The focal length is the distance between the image that is being magnified and the centre of the magnifying lens. A real image can only be formed when the object is further away from the lens than the focal length. Therefore, in this question, the image is virtual, as the object is closer to the lens than the focal length. The answer to question 4 is D because the index of refraction cannot be less than 1. The answer to question 5 is D because only concave mirrors can produce real images; other types produce virtual images. For question 6, the answer is D. In the rainbow, each of the colours refracts at a slightly different angle; red has the smallest refractive index and violet the largest. Of the options, orange is closest to red. For question 12, A is the answer. A higher operating temperature is not a reason fluorescent lamps are better than incandescent lamps because they have a lower operating temperature. Question 15: all of these are characteristics of different electromagetic waves. For question 18, B is true - special care must be taken when low illuminance is required to reduce glare. The answer to question 19 is B - a compound microscope makes use of two lenses. For question 20, the answer is 5 meters away. The illuminance (E) is equal to light intensity (I) divided by the square distance from the light source (d). Therefore, 4 = 100/d squared. To switch this around, d squared is equal to 100/4 = 25. Then find the square root of 25, which is 5.</span>
