Question

Give the chemical formula for (a) carbonic acid, (b) sodium cyanide, (c) potassium hydrogen carbonate, (d) acetylene, (e) iron pentacarbonyl.

Short answer

(a) H2CO3, (b) NaCN, (c) KHCO3, (d) C2H2, (e) Fe(CO)5

Step-by-step solution

(a) Carbonic Acid

Carbonic Acid is composed of Carbon, Hydrogen, and Oxygen. The compound is formed between Carbonate ion (CO3^2-) and Hydrogen ion (H^+). Since Carbonate ion has a -2 charge and Hydrogen ion has a +1 charge, we need to balance the charges in the compound by having two Hydrogen ions. So, the chemical formula for Carbonic Acid would be H2CO3.

(b) Sodium Cyanide

Sodium Cyanide is composed of Sodium and the Cyanide ion. Sodium has a +1 charge (Na^+) and Cyanide ion has a -1 charge (CN^-). Therefore, the chemical formula for Sodium Cyanide would be NaCN, since the charges of the two ions are balanced in a 1:1 ratio.

(c) Potassium Hydrogen Carbonate

Potassium Hydrogen Carbonate is composed of Potassium, Hydrogen, and the Carbonate ion. Potassium has a +1 charge (K^+), Hydrogen has a +1 charge (H^+), and the Carbonate ion has a -2 charge (CO3^2-). To balance the charges, we need one Potassium ion and one Hydrogen ion. So, the chemical formula for Potassium Hydrogen Carbonate would be KHCO3.

(d) Acetylene

Acetylene is composed of Carbon and Hydrogen. The compound is formed by two Carbon atoms connected by a triple bond and each Carbon atom connected to one Hydrogen atom. The chemical formula for Acetylene would be C2H2.

(e) Iron Pentacarbonyl

Iron Pentacarbonyl consists of Iron and five Carbon monoxide molecules. Since the number of Carbon monoxide molecules is "penta" (which means five), we need to combine Iron with five CO molecules. So, the chemical formula for Iron Pentacarbonyl would be Fe(CO)5.