Unit 1
This type of bond holds hydrogen and oxygen together in a water molecule due to unequal sharing of electrons.
Covalent bond or Polar covalent bond
This type of reaction occurs when water breaks down into hydrogen gas and oxygen gas during electrolysis.
decomposition reaction
This is the number of particles in one mole, equal to 6.02 × 10²³.
Avogadro’s number
This is a homogeneous mixture made when a substance is dissolved in a liquid.
solution
This state of matter has properties such as volume, pressure, temperature, and number of particles.
Gas
This chemical property explains why oxygen pulls electrons more strongly than hydrogen in a water molecule.
Electronegativity
In green hydrogen production, hydrogen ions become hydrogen gas by gaining something in a redox reaction.
electrons
This term is used to describe a counting unit for atoms, molecules, or ions.
mole
This term describes how much solute is present in a solution.
concentration
These scientific relationships describe how pressure, volume, and temperature of a gas change in relation to one another.
gas laws
This process adds energy to water to separate it into hydrogen and oxygen gases.
electrolysis
This reaction happens when a fuel reacts with oxygen to produce energy and a new substance, like hydrogen burning to make water.
combustion reaction
According to the equation 2 H₂O → 2 H₂ + O₂, this many moles of hydrogen gas are produced from 2 moles of water.
2 moles
Adding salts or acids to water helps it do this, which is necessary for electrolysis to split water into hydrogen and oxygen.
conduct electricity / increase conductivity
This gas produced during electrolysis has the lowest density of all gases and is used as a clean fuel source.
hydrogen gas
After water is split, hydrogen atoms combine to form H₂ gas, which stores this type of energy that can be released later.
chemical energy / energy
During water splitting, hydrogen atoms gain electrons to form H₂ gas in this type of reaction.
chemical reaction
This branch of chemistry uses mole ratios from balanced equations to predict how much product will form from a given amount of reactant.
stoichiometry
Solutions that contain these can carry an electric current and affect the efficiency of hydrogen production.
ions
Because hydrogen must be kept compact for storage and transport, it is stored in tanks under this condition.
high pressure
This property of the H–O bonds in water explains why energy from renewable electricity is required to split water during electrolysis.
Bond strength
In this reaction, oxygen atoms lose electrons to form O₂ gas during water splitting.
decomposition reaction
This factor in a solution affects the speed of hydrogen production and the amount of energy required.
concentration of ions
When used as a fuel, this gas produces only water and no carbon dioxide, helping reduce greenhouse gas emissions.
hydrogen