Answer:
NH3(aq)
Explanation:
Gold III hydroxide is an inorganic compound also known as auric acid. It can be dehydrated at about 140°C to yield gold III oxide. Gold III hydroxide is found to form precipitates in alkaline solutions hence it is not soluble in calcium hydroxide.
However, gold III hydroxide forms an inorganic complex with ammonia which makes the insoluble gold III hydroxide to dissolve in ammonia solution. The equation of this complex formation is shown below;
Au(OH)3(s) + 4 NH3(aq) -------> [Au(NH3)4]^3+(aq) + 3OH^-(aq)
Hence the formation of a tetra amine complex of gold III will lead to the dissolution of gold III hydroxide solid in aqueous ammonia.
Answer:
A pure substance has a constant composition and cannot be separated into simpler substances by physical means. There are two types of pure substances: elements and compounds. ... The ratio of the elements in a compound are always constant. (Water is always 11 % Hydrogen and 89 % oxygen).
Explanation:
<h2>A sample of gold (Au) has a mass of 72.04g. Calculate the number of atoms of gold (Au): It is equal to ==2.207 x 10²³ number of atoms </h2>
Explanation:
we can find number of atoms in a given sample by the formula :
Number of atoms = Given mass /atomic mass x Avogadro's number
or , it can be written as :
Number of atoms = given mass /atomic mass x 6.022 x 10²³
Now in above asked question , the values given are :
Mass of sample of gold = 72.04g
Atomic mass of gold : 196.6
Avogadro's number = 6.023 x 10²³
so, using the above formula we have :
Number of atoms = 72.04 /196.6 x 6.022 x 10²³
= 0.3664 x 6.022 x 10²³
=2.207 x 10²³ number of atoms
It’s “c. +1” because the Sodium is losing a proton, which has a positive chage