Answer: Gold.
Explanation: Water, CO2, and table salt are compounds. They are composed of two or more separate elements; a mixture, where as gold is neither.
The standard Gibbs free energy of formation ΔGf° of Rb(s), H2(g) and Pb(s) are all zero. Similar to enthalpies of formation, the values of the standard Gibbs energies of formation are zero for the elements in their most stable forms at room conditions 298 Kelvin and one atmosphere pressure.
Kb = [HA} [OH-] / [A-] where [A-] represents the concentration of CN- (.068M)
Kb = Kw / Ka = 1 x10-14 / 4.9 x 10-10 = 2 x 10-5
Since this is a salt solution which could be considered to have formed from the neutralization of a strong base (NaOH) and a weak acid (HCN), the Na+ will have no effect on the pH of the solution while the CN- ion will undergo hydrolysis:
CN- + H2O --> HCN + OH-
Based on this equation, the quantities of HCN and OH- produced must be the same and therefore [HCN]=[OH-]. We will set this equal to x.
Plugging into the original equation yields:
2 x 10-5 = x2 / .068 M
Solving for x yields 1.2 x 10-3 whidh is equal to the [OH-]
The pOH then is equal to -log (1.2x10-3) = 2.9
The pH of the solution would be 14 - 2.9 = 11.1
Answer:
Explanation:
The structure of the methane, CH4, molecule exhibits single covalent bonds. Covalent bonding involves the sharing of electrons. In the methane molecule, the four hydrogen atom share one electron each with the carbon atom