The correct answers are options C, that is, silver tarnishes and becomes black when exposed to oxygen, and option E, that is, diesel fuel burns when it is heated.
Chemical changes refer to the modifications in which the chemistry at molecular level is modified as the initial substance gets transformed into a new and different final substance. This change occurs with the dissociation of old bond and production of new bonds respectively.
Silver gets tarnished and becomes black when exposed to oxygen. This refers to a chemical change as silver a white and lustrous substance gets transformed into a tarnish black final substance. However, silver does not easily react with oxygen at usual circumstances. It easily reacts with sulfur comprising components in the air and generates black compound as Ag₂S.
Burning of diesel fuel when it is heated. Diesel refers to a mixture of hydrocarbons varying approximately from C₁₀H₂₀ to C₁₅H₂₈. When these hydrocarbons get burnt they generate novel substances, that is, carbon dioxide and water. Hence, it is also a chemical reaction.
There are two kinds of mixtures
a) homogeneous : the boundary of the two components is not physically distinct
b) heterogeneous:the boundary of the two components is physically distinct
the following separation techniques are common for mixtures
1) filtration: if the two components are forming heterogeneous mixture we can separate them by filtration.
2) boiling: if boiling point of one of the components is less than other
3) magnetic separation: if one of the component is magnetic
4)sieve method: for solid components with difference in size of particles
5) hand picking
Thus the correct match will be as shown in the figure
Explanation:
The given data is as follows.
Solvent 1 = benzene, Solvent 2 = water
= 2.7,
= 100 mL
= 10 mL, weight of compound = 1 g
Extract = 3
Therefore, calculate the fraction remaining as follows.
![f_{n} = [1 + K_{p}(\frac{V_{S_{2}}}{V_{S_{1}}})]^{-n}](https://tex.z-dn.net/?f=f_%7Bn%7D%20%3D%20%5B1%20%2B%20K_%7Bp%7D%28%5Cfrac%7BV_%7BS_%7B2%7D%7D%7D%7BV_%7BS_%7B1%7D%7D%7D%29%5D%5E%7B-n%7D)
= ![[1 + 2.7(\frac{100}{10})]^{-3}](https://tex.z-dn.net/?f=%5B1%20%2B%202.7%28%5Cfrac%7B100%7D%7B10%7D%29%5D%5E%7B-3%7D)
= 
= 
Hence, weight of compound to be extracted = weight of compound - fraction remaining
= 1 - 
= 0.00001
or, = 
Thus, we can conclude that weight of compound that could be extracted is
.
The other name for a condensation reaction would be dehydration reaction. This reaction happens when two molecules or compounds react forming a larger molecule and a small H2O molecule. From the name itself, water should be produced.
The answer is C because the weight is going down so they form a gas.