How to find an equivalent

How to find an equivalent

Equivalent is called the particle which is chemically equivalent (is equivalent) in the acid and main reactions to one ion of hydrogen, and in reactions of oxidation-reduction type - to one electron. The equivalent is expressed by number without dimension whereas equivalent weight is measured in g/mol.

How to define initial concentration of substance

How to define initial concentration of substance

The substances entering chemical reaction undergo changes of structure and the building, turning into reaction products. Concentration of initial substances decreases up to zero if reaction goes all the way. But the return reaction when products break up to initial substances can proceed. In that case balance when the speed of direct and return reaction becomes identical is established. Certainly, equilibrium concentration of substances will be less initial.

How to calculate a mass fraction if density is known

How to calculate a mass fraction if density is known

The mass fraction is the size showing what relation of mass of any component which is a part of solution or alloy, or mix to the lump of all components. She can say or in unit shares, or as a percentage. It is easy to understand that the mass fraction is closer to unit, the maintenance of this component in solution, alloy or mix is more.

What is graphene: way of receiving, property and application

What is graphene: way of receiving, property and application

Theoretically scientists knew about a possibility of existence of graphene for a long time. However for the first time this interesting material was received in 2004 by specialists of the Manchester university K. Novoselov and A. Geym. For the developments these scientists in 2010 were conferred the Nobel Prize.

Heptane isomers: general characteristic and application

Heptane isomers: general characteristic and application

Heptane – organic matter, with formula C7H16. It represents liquid with a density about 0.7 grams/cm3. Thanks to the fact that in its molecule there are neither double, nor threefold communications, and polarization of communication between atoms of carbon and hydrogen quite weak, heptane is quite steady from the chemical point of view.