You will often work with salts of , , and in the laboratory. (All are found in nature, and all are important economically.) If you have a solution containing these three ions, each at a concentration of 0.10 M, what is the order in which their hydroxides begin to precipitate as aqueous NaOH is slowly added to the solution? Formula Enter an integer to indicate order: 1 = first, 2 = second, 3 = last : : :

1) Fe³⁺

2) Al³⁺

3) Pb²⁺

Explanation:

Because all of the metal ion concentrations are the same, the order that they precipitate will be dependent on the values of each individual precipitate. The lower the , the less OH⁻ needed in solution to precipitate.

The three values are

= 2.6 x 10⁻³⁹ for Fe(OH)₃,

= 1.9 x 10⁻³³ for Al(OH)₃

= 1.4 x 10⁻¹⁵ for Pb(OH)₂

This means that the ions will precipitate in the following order Fe³⁺ then Al³⁺ then Pb²⁺

Note: if too much OH⁻ is added Al³⁺ will redissolve into solution because of the formation of the soluble complex Al(OH)⁻₄ ( = 1.1 x 10³³)

the earth would become to overheated and everything alive on it will eventually die from overheating. plants will eventually die as well, water will evaporate, and it will be nothing but a hot planet without anything living on it.

ca has a crystalline lattice with positive ions (since it is a metal, metals are positively charged) and electrons flow freely in its structure since the ca atoms have a large nuclear radius so the electrons are not tightly held, therefore the electrons can flow freely since they are not being highly attracted by the nucleus. moreover, one of the properties of metals are that they are conductors of electricity, thus proving ca is the element.