enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Empirical formula - Wikipedia

    en.wikipedia.org/wiki/Empirical_formula

    Glucose (C 6 H 12 O 6), ribose (C 5 H 10 O 5), Acetic acid (C 2 H 4 O 2), and formaldehyde (CH 2 O) all have different molecular formulas but the same empirical formula: CH 2 O.This is the actual molecular formula for formaldehyde, but acetic acid has double the number of atoms, ribose has five times the number of atoms, and glucose has six times the number of atoms.

  3. List of mass spectrometry software - Wikipedia

    en.wikipedia.org/wiki/List_of_mass_spectrometry...

    Universal Mass Calculator Freeware: UMC is programmed as a mass spectrometry tool to assist interpreting measurement results, mainly derived from molecular or quasi-molecular ions. It can be used for the calculation of: Mass deviation (mmu or ppm) of measured mass from given empirical formula; Mass differences of two empirical formulas

  4. Dumas method of molecular weight determination - Wikipedia

    en.wikipedia.org/wiki/Dumas_method_of_molecular...

    Dumas used the method to determine the vapour densities of elements (mercury, phosphorus, sulfur) and inorganic compounds. [3] Today, modern methods such as mass spectrometry and elemental analysis are used to determine the molecular weight of a substance.

  5. Mass fraction (chemistry) - Wikipedia

    en.wikipedia.org/wiki/Mass_fraction_(chemistry)

    Mass fraction can also be expressed, with a denominator of 100, as percentage by mass (in commercial contexts often called percentage by weight, abbreviated wt.% or % w/w; see mass versus weight). It is one way of expressing the composition of a mixture in a dimensionless size ; mole fraction (percentage by moles , mol%) and volume fraction ...

  6. Non-stoichiometric compound - Wikipedia

    en.wikipedia.org/wiki/Non-stoichiometric_compound

    Non-stoichiometric compounds are chemical compounds, almost always solid inorganic compounds, having elemental composition whose proportions cannot be represented by a ratio of small natural numbers (i.e. an empirical formula); most often, in such materials, some small percentage of atoms are missing or too many atoms are packed into an ...

  7. Formula unit - Wikipedia

    en.wikipedia.org/wiki/Formula_unit

    In most cases the formula representing a formula unit will also be an empirical formula, such as calcium carbonate (CaCO 3) or sodium chloride (NaCl), but it is not always the case. For example, the ionic compounds potassium persulfate ( K 2 S 2 O 8 ), mercury(I) nitrate Hg 2 (NO 3 ) 2 , and sodium peroxide Na 2 O 2 , have empirical formulas of ...

  8. Mass spectral interpretation - Wikipedia

    en.wikipedia.org/wiki/Mass_spectral_interpretation

    [1] [2] Mass spectra is a plot of relative abundance against mass-to-charge ratio. It is commonly used for the identification of organic compounds from electron ionization mass spectrometry. [3] [4] Organic chemists obtain mass spectra of chemical compounds as part of structure elucidation and the analysis is part of many organic chemistry ...

  9. Bicarbonate - Wikipedia

    en.wikipedia.org/wiki/Bicarbonate

    The bicarbonate ion (hydrogencarbonate ion) is an anion with the empirical formula HCO − 3 and a molecular mass of 61.01 daltons; it consists of one central carbon atom surrounded by three oxygen atoms in a trigonal planar arrangement, with a hydrogen atom attached to one of the oxygens.