1 Kilowatt hour is equal to _____ eV.

Hint: The kilowatt-hour is a composite unit of energy equal to one kilowatt (kW) of power sustained for one hour. Expressed in the standard unit of energy in the International System of Units (SI), the joule (symbol J), it is equal to 3600 kilojoules (3.6 MJ).

Complete answer:
Kilowatt hour and electron volt are units of energy. The conversion factor can be deduced from their relationship with the derived SI unit for energy, the joule.
The hour is a unit of time listed among the non-SI units accepted by the International Bureau of Weights and Measures for use with the SI. Its combination with the kilowatt, a standard SI unit, is therefore permitted within the standard.
A widely used symbolic representation of the kilowatt-hour is "kWh", from the unit symbols of its component units, kilowatt and hour. It is commonly used in commercial, educational, and scientific publications and in the media. It is also the usual unit representation in electrical power engineering. This common representation does not comply with the style guide of the International System of Units (SI).
All the SI prefixes are commonly applied to the watt-hour: a kilowatt-hour is 1,000 Wh (kWh); a megawatt-hour is 1 million Wh (MWh); a milliwatt-hour is 1/1000 Wh (mWh) and so on.
\[\therefore \] 1 Kilowatt hour is equal to \[2.247\times {{10}^{25}}eV\].

Note:
The kilowatt-hour is commonly used by electrical energy providers for purposes of billing, since the monthly energy consumption of a typical residential customer ranges from a few hundred to a few thousand kilowatt-hours. Megawatt-hours (MWh), gigawatt-hours (GWh), and terawatt-hours (TWh) are often used for metering larger amounts of electrical energy to industrial customers and in power generation. The terawatt-hour and petawatt-hour (PWh) units are large enough to conveniently express the annual electricity generation for whole countries and the world energy consumption.