In the crystallization process the solid compound is dissolved in the solvent at elevated temperature and the crystallize product obtained by slow cooling of the solution. Here the solubility of acetanilide at 100°C is 1g per 20mL of water. Thus to dissolve 500mg of acetanilide at high temperature that is 100°C we need 10mL of water.
Now at 25°C after the re-crystallization there will be some amount of dissolve acetanilide. Which can be calculated as- 185mL of water is needed to dissolve 1g or 1000mg of acetanilide at 25°C. Thus in 10mL of water there will be 
gmg of acetanilide.
Fixed vs Variable Oxidation is given below.
Explanation:
1.In its compounds, hydrogen has an oxidation number of +1, except. hydrides where the. oxidation number of hydrogen is -1. In their compounds, the metals with fixed oxidation states have the oxidation number that. corresponds with the fixed oxidation number.
A variable oxidation state is a value that determines the charge of the atom depending on certain conditions.
2. Oxidation state of elements is considered to be of the most important in the study of chemistry. For some elements, this figure is constant known as fixed oxidation , while for others it is variable is called variable oxidation state.
3. MgCl2 : magnesium is in Group IIA and all elements in Group IIA have fixed oxidation numbers of +2
FeCl2 : iron has a variable oxidation number of either +2 or +3 and is not fixed
<span>El Niño during the time of 1997 to 1998 caused drought in Southeast Asia and flooding in much of Latin America and in the Horn of Africa due to significant amounts of rainfall. The effects in both places were numerous deaths. In areas where it flooded, mudslides occurred and spoiled seed stores. In areas of drought, crops were extremely diminished and let to starvation.</span>
