Answer:
17)A. Solids
18) A. Frequently collide with each other and with surface of ballon
19) D. Particles are smaller at lower pressure.
Answer : The oxidation state of Mg in Mg(s) is (0).
Explanation :
Oxidation number or oxidation state : It represent the number of electrons lost or gained by the atoms of an element in a compound.
Oxidation numbers are generally written with the sign (+) and (-) first and then the magnitude.
Rules for Oxidation Numbers are :
The oxidation number of a free element is always zero.
The oxidation number of a monatomic ion equals the charge of the ion.
The oxidation number of Hydrogen (H) is +1, but it is -1 in when combined with less electronegative elements.
The oxidation number of oxygen (O) in compounds is usually -2.
The oxidation number of a Group 17 element in a binary compound is -1.
The sum of the oxidation numbers of all of the atoms in a neutral compound is zero.
The sum of the oxidation numbers in a polyatomic ion is equal to the charge of the ion.
The given chemical reaction is:
In the given reaction, the oxidation state of Mg in Mg(s) is (0) because it is a free element and the oxidation state of Mg in 
is (+2).
Hence, the oxidation state of Mg in Mg(s) is (0).
Answer:
ΔG°rxn = -69.0 kJ
Explanation:
Let's consider the following thermochemical equation.
N₂O(g) + NO₂(g) → 3 NO(g) ΔG°rxn = -23.0 kJ
Since ΔG°rxn < 0, this reaction is exergonic, that is, 23.0 kJ of energy are released. The Gibbs free energy is an extensive property, meaning that it depends on the amount of matter. Then, if we multiply the amount of matter by 3 (by multiplying the stoichiometric coefficients by 3), the ΔG°rxn will also be tripled.
3 N₂O(g) + 3 NO₂(g) → 9 NO(g) ΔG°rxn = -69.0 kJ
Answer: b suspension
a suspension is a heterogeneous mixture that contains solid particles sufficiently large for sedimentation . The particles may be
visible to the naked eye, usually must be larger than one micrometer , and will eventually settle, although the mixture is only classified as a suspension when and while the particles have not settled out. A suspension is a heterogeneous mixture in which the solute particles do not dissolve , but get suspended throughout the bulk of the solvent , left floating around freely in the medium. [1] The internal phase (solid) is dispersed throughout the external phase (fluid) through mechanical agitation , with the use of certain excipients or suspending agents.
An example of a suspension would be sand in water. The suspended particles are visible under a
microscope and will settle over time if left undisturbed. This distinguishes a suspension from a colloid , in which the suspended particles are smaller and do not settle.
Colloids and suspensions are different from
solution , in which the dissolved substance (solute) does not exist as a solid, and solvent and solute are homogeneously mixed.
