Determine the chemical formula for the compound, chromate(iii). a) k3[cr(nh2ch2ch2nh2)3] b) [k(nh2ch2ch2nh2)3]cr3+ c) [kcr(nh2ch2ch2nh2)3]3+ d) k2[cr(nh2ch2ch2nh2)4] e) [cr(nh2ch2ch2nh2)2]k2

The correct answer is (A).

Explanation:

Potassium-trisethylene-diamine chromate(III)

Potassium is coming first in name which means that potassium is present as cation.

In the complex, 3 molecules of 'ethylene-diamine' is present as an dianion and forms a complex with Chromium (III) metal, making the overall charge on the coordination sphere as (-3).

So, to make a neutral complex, 3 potassium ions are required.

Hence, the structure of the complex is

c.

explanation:

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.