Answer:
The answer to your question is below
Explanation:
Polyatomic ions are ions composed for more than 1 atom. There are polyanions and polycations.
Polyanions have a negative charge and polycations have a positive charge.
Examples
Polyanions Polycations
acetate CH₃COO⁻ ammonium NH₄⁺¹
bromate BrO₃⁻
chlorate ClO₃⁻
hydroxide OH⁻
nitrate NO₃⁻
nitrite NO₂⁻
sulfate SO₄⁻²
phosphate PO₄⁻³
permanganate MnO₄⁻
We write parentheses before or after a polyatomic ion to emphasize that the oxidation number of the atom which interacts with it affects all the atoms that form part of the polyatomic ion.
A displacement reaction will occur from the system given above. The chlorine molecules will displace the bromide ions in the solution of sodium bromide. The reaction will yield to sodium chloride and bromine. The reaction will be:
2NaBr + Cl2 = 2NaCl + Br2
1) Chemical reactions produce new substances
Ans (d)
2) The symbol, Δ in a chemical reaction means that heat of supplied to the reaction.
Ans (a)
3) A skeleton equations does not show the reaction stoichiometry, i.e. the relative amounts of reactants and products.
Ans (d)
Answer:
The correct option is;
D)
Explanation:
The given reaction is presented as follows;
NH₄Cl (s) → NH₃ (g) + HCl (g) ΔH° = 176 kJ/mol, ΔS° = 0.285 kJ/(mol·K)
We note that the Gibbs free energy, ΔG° is represented by the following equation;
ΔG° = ΔH° - T·ΔS°
Where:
T = Temperature (Kelvin)
The reaction will be spontaneous for exergonic reactions, ΔG° < 0 and it will not be spontaneous for endergonic reaction, ΔG° > 0
At room temperature, T = 25 + 273.15 = 298.15 K
Which gives;
ΔG° = 176 - 298.15 × 0.285 = 91.03 kJ/mol which is > 0 Not spontaneous reaction
At 800°C, we have;
T = 273.15 + 800°C + 1073.15 K
ΔG° = 176 - 1073.15 * 0.285 = -129.85 kJ/mol which is < 0 the reaction will be spontaneous
The correct option is therefore, that at room temperature, the reaction is not spontaneous. However, at high temperatures. like 800 °C, the free energy value turns negative and this reaction becomes spontaneous.
