Answer:
B. Lower than 100 °C because hydrogen sulfide has dipole-dipole interactions instead of hydrogen bonding.
Explanation:
Intermolecular bonds exists between seperate molecules or units. Their relative strength determines many physical properties of substances like state of matter, solubility of water, boiling point, volatility, viscosity etc. Examples are Van der waals forces, hydrogen bonds and crystal lattice forces.
In hydrogen sulfide, the intermolecular bond is a dipole-dipole attraction which is a type of van der waals attraction. It occurs as an attraction between polar molecules. These molecules line such that the positive pole of one molecule attracts the negative pole of another.
In water, the intermolecular bond is hydrogen bonds in which an electrostatic attraction exists between the hydrogen atom of one molecule and the electronegative atom of a neighbouring molecule.
Based on their relative strength:
Van der Waals forces < Hydrogen bonding forces < crystal lattice
This makes water boil at a higher temperature than hydrogen sulfide.
Answer:
<em>It is a chemical reaction in which the reactants form products and products react together to give reactants back. That means reversible reactions can go in both directions forward as well as backward direction.</em>
Answer: Predominant tropical easterly winds sweep across the central and southern portions of the state, keeping the temperatures mild
Explanation:
bc
Answer:
Substances can change phase—often because of a temperature change. At low temperatures, most substances are solid; as the temperature increases, they become liquid; at higher temperatures still, they become gaseous.
The process of a solid becoming a liquid is called melting. (an older term that you may see sometimes is fusion). The opposite process, a liquid becoming a solid, is called solidification. For any pure substance, the temperature at which melting occurs—known as the melting point—is a characteristic of that substance. It requires energy for a solid to melt into a liquid. Every pure substance has a certain amount of energy it needs to change from a solid to a liquid. This amount is called the enthalpy of fusion (or heat of fusion) of the substance, represented as ΔHfus. Some ΔHfus values are listed in Table 10.2 “Enthalpies of Fusion for Various Substances”; it is assumed that these values are for the melting point of the substance. Note that the unit of ΔHfus is kilojoules per mole, so we need to know the quantity of material to know how much energy is involved. The ΔHfus is always tabulated as a positive number. However, it can be used for both the melting and the solidification processes as long as you keep in mind that melting is always endothermic (so ΔH will be positive), while solidification is always exothermic (so ΔH will be negative).
Answer:
Explanation:
The formula of nickeI(II)nitrate hexahydrate is
Ni(NO3)2.6H2O
So option (c) is correct.
