**Decomposition of Water:**

The decomposition of water involves the splitting of water molecules (H2O) into their constituent elements, hydrogen (H2) and oxygen (O2), through the process of electrolysis. This process occurs when an electric current is passed through water, causing the water molecules to dissociate.

**Faraday's Laws of Electrolysis:**

To calculate the time required for the complete decomposition of a given amount of water using a certain current, we can use Faraday's laws of electrolysis. These laws relate the amount of substance produced or consumed during electrolysis to the quantity of electricity passed through the electrolyte.

**Faraday's First Law:**

The amount of substance produced or consumed during electrolysis is directly proportional to the quantity of electricity passed through the electrolyte.

Mathematically, this can be represented as:

m = ZQ

Where:
- m is the mass of the substance produced or consumed
- Z is the electrochemical equivalent of the substance
- Q is the quantity of electricity passed through the electrolyte

**Faraday's Second Law:**

The quantity of electricity required to produce or consume a certain amount of substance is directly proportional to the equivalent weight of the substance.

Mathematically, this can be represented as:

Q = nF

Where:
- Q is the quantity of electricity passed through the electrolyte
- n is the number of moles of substance produced or consumed
- F is the Faraday constant (approximately 96,485 C/mol)

**Calculating the Time:**

To calculate the time required for the complete decomposition of 4 moles of water using a 4 Ampere current, we need to follow these steps:

1. Calculate the quantity of electricity required (Q) using Faraday's Second Law:

Q = nF
Q = 4 mol * 96,485 C/mol
Q = 385,940 C

2. Calculate the time required (t) using the equation:

Q = It

Where:
- I is the current (4 A)
- t is the time in seconds to be determined

Rearranging the equation, we have:

t = Q / I
t = 385,940 C / 4 A
t = 96,485 s

Therefore, the time required for the complete decomposition of 4 moles of water using a 4 Ampere current is 96,485 seconds.

**Conclusion:**

In conclusion, it would take approximately 96,485 seconds (or 26.8 hours) for the complete decomposition of 4 moles of water using a 4 Ampere current. This calculation is based on Faraday's laws of electrolysis, which relate the quantity of electricity passed through the electrolyte to the amount of substance produced or consumed during electrolysis.