In naming compounds, one has to know the symbol for each element. Magnesium's symbol is Mg. In its ionic form, it is symbolized as Mg2+. Chlorate ions are polyatomic. Chlorite is ClO2-, chlorate is ClO3- and perchlorate is ClO4-. Next, when combining elements to form compounds, you 'cross multiply' their ionic charges. In doing so, Magnesium Chlorate is
The balanced chemical reaction would be:
16Al + 3S8 = 8Al2S3
We need to determine which reactants are the limiting and the excess. To determine this, we use the initial amounts of the reactants given above. We need to convert them into units of moles and use the balanced reaction to relate the substances calculating the amount needed to react all of the reactants. We do as follows:
63.8 g Al ( 1 mol Al / 26.98 g Al ) ( 3 mol S8 / 16 mol Al ) (256.48 g S / 1 mol S )= 113.72 g S8 needed to completely react
72.3 g S8 ( 1 mol S8 / 256.48 g S8) ( 16 mol Al / 3 mol S8 ) ( 26.98 g / mol ) = 40.56 g Al needed to completely react
Therefore, the excess would be Al and the limiting would be sulfur. The amount excess would be 63.8 g Al - 40.56 g Al = 23.24 g Al
D is the correct answer! YAYYYYYYAA!!
Chemical compounds have chemically bonded molecules so that they exhibit different properties (i.e. chemical) compared to the individual molecules comprising the compound. Mixtures are simply the combinations of different molecules and compounds that are not chemically bonded together, and can therefore be separated by physical means. Mixtures usually retain the properties of its components. The hydrogen and oxygen molecules in a mixture do not form strong bonds between each other. The molecules of both gases are only contained in the same space or volume and the individual molecules retain their chemical properties.
A compound containing hydrogen and oxygen molecules exhibit different chemical (and even physical) properties compared to the individual molecules themselves.
Water for example, is a compound with 2 hydrogen atoms and 1 oxygen atom, chemically-bonded together. Hydrogen gas is highly flammable, water is not. Oxygen gas is an essential reagent for combustion (or burning) reactions, water is not.
Thus, throwing a lighted match to a gaseous mixture of hydrogen
and oxygen
would create fire, or even an explosion (since hydrogen is flammable and oxygen feeds the reaction). Throwing a match to water vapor
would not create fire.