Answer:
A.
Explanation:
Water was added to the reaction after the completion of the reaction so as to lower the solubility if the product in the solution therefore, the product can be precipitated out. On adding water the reaction moves in forward direction and more product is formed. (By Le Chatelier's principle). Thus, the precipitation occurs. Hence, option A is correct.
Answer:
Atmospheric Pressure:
- It is the force exerted on a surface by the air above it as gravity pulls it to Earth. Atmospheric pressure is commonly measured with a barometer. In a barometer, a column of mercury in a glass tube rises or falls as the weight of the atmosphere changes.
Explanation:
Hope this helps
The formula of quinine is C20H24N2O2 and the respective atomic weights are C= 12.0096 , H = 1.008, N=14.0067 and O=15.9994 so C x 20 = 24.192 and H x24= 24.192 and N x 2 = 28.0134 and O x 2 = 31.998 for an approximate total of 324.4 grams/mole for the molecular weight of quinine.
Aerial fireworks are usually manufactured as a shell that is made up of four parts. The container consists of pasted paper. The fuse allows the shell to reach the desired altitude before exploding. A bursting charge made of black powder (like a firecracker) is at the center of the shell.
Introduction of essay: talk about the three models used in science (mathematical, conceptual and physical), how do they help scientists understand complex ideas?, introduce the formula for density (as a mathematical model) and the particle model (as a conceptual model ... i think it is...) in science.
Body paragraph of essay: further discuss the properties of the models, link them to the examples (formula of density and the particle model) and compare and contrast (the strengths and weaknesses of each model) e.g. “Mathematical models help scientists to understand the underlying relationship between two concepts. Although a mathematical model is short and concise it is often hard to describe the model conceptually or physically and its therefore harder to get the full picture of how a scientific process works physically. A conceptual model is helpful for intuitive ideas in science like the particle model that would be harder to describe mathematically, due to how broad it is.” Etc etc.
Conclusion paragraph of the essay: “to conclude, models in science are important because they help us to understand difficult and intuitive ideas in a more clear and concise manner.” Etc etc.
Hope this helped - keep in mind that i don’t know the actual difference between conceptual and physical models so look through your books notes for more info for your essay.
