Chemistry Questions

Fractional distillation is the process of seperation of a mixture of two or more liquids into the different fractions, which differ fairly widely in their boiling points. The liquid with a lower boiling point will be vaporized first and hence would be the distillate (first fraction). Eg. Ethyl alcohol has a boiling point of 78.10C and water 1000C. When a mixture of these two liquids is heated, alcohol vaporizes first and is collected separately as the distillate. 

True, Water is a Pure substance and not a mixture.

We know that, A mixture is when two or more substances combine physically together. You can find that the mixture retains the properties of the original components.

In water, two hydrogen atoms combine with one oxygen atom chemically, forming a new substance that has properties different from hydrogen alone or oxygen alone.

Therefore, water is not a mixture; it is a compound and it is pure.

Corn, sugar cane, and sorghum are C4 plants. These plants are economically important in part because of their relatively high photosynthetic efficiencies compared to many other crops.

Electronegativity is the tendency for an atom to attract electrons. There are general trends on the periodic table which you can use to determine the relative electronegativity for different elements, but otherwise you can also look at their valence shell and effective nuclear charge to determine their relative electronegativity.

Here from the given options, Lithium has least tendency to attract electrons and thus has a lower electronegativity.

In chemistry, Weak bonds are those forces of attraction that, do not take a large amount of energy to break.

For example, hydrogen bonds are broken by energies in the order of 4 - 5 kcal/mol.

Ionic bonds, hydrogen bonds and van der Waals interactions are considered weak bonds.

Weak bonds are transient and easily reversible.