Answer:
The concentration of the products and reactants is constant.
Explanation:
Once the reversible reaction that proceeds forward and backward simultaneously has reached it's state of chemical equlibrium, the concentration of products and reactants become constant.
This means that the rate at which the reactants react to form products becomes equal to the rate at which products react to form the reactants again. At this point there will be no further change in the concentration of reactants and products with time. In chemical equilibrium the concentration of a reactant or a product is expressed in moles per cubic decimeter ( mol / dm^3.
The mass of the product in a chemical reaction must be equal the mass of the reactants.
Answer:
Transition metals like Fe have multiple oxidation states and hence they need to be specified by roman numerals. In contrast, Ba is an alkali metal with a constant +2 oxidation state which need not be specified in the compound names.
Explanation:
Oxidation state of an element can be ascribed to the loss or gain of electrons. Metals in general are electropositive i.e. they tend to lose electrons and form cations.
Iron (Fe) is a transition metal and belongs to the 'd-block' within the periodic table. Transition metals are characterized by the presence of five d-orbitals that are partially filled with electrons of similar energies. Thus for d-block elements there are several electrons that can be removed which results in multiple oxidation states. In the case of Fe the most common oxidation states are +2 and +3. Therefore, for any given compound of iron it is imperative to specify its oxidation state. In this case the compound is Fe(NO3)2 where Fe is in the +2 oxidation state as represented by the roman numeral 'II', hence iron (II) nitrate.
Barium (Ba) in contrast is an alkaline earth metal with a single oxidation state of +2. Any compound of Ba will only exhibit a +2 oxidation state which is assumed to be the case and therefore not explicitly specified, hence Ba(NO3)2 is called barium nitrate and not barium (II) nitrate.
Answer: Y → Z → X
Explanation:
The three states of matter shown in the picture are:
X) solid - in solids, molecules are bond together, so they are not free to move. They can only vibrate about their position - therefore they have the least freedom of motion
Z) liquid - in liquids, molecules are not bond, so they can move past each other. However, there are still strong intermolecular forces that keep the molecules close to each other, so they are not completely free to move - so this is the intermediate amount of motion
Y) Gas - in gases, molecules are completely free to move, since the intermolecular forces between them are negligible. Therefore, this is the state where molecules have the greatest amount of motion
