http://freestuffforbabies.net/in-a-lehman-explanation-what-are-the-main-differences-between-molecular-weight-and-formula-weight.html Free Stuff For Your Baby Sat, 19 May 2012 13:37:05 +0000 hourly 1 http://wordpress.org/?v=3.3.2 http://freestuffforbabies.net/in-a-lehman-explanation-what-are-the-main-differences-between-molecular-weight-and-formula-weight.html/comment-page-1#comment-5811 clevelan Wed, 30 Dec 2009 07:33:08 +0000 http://freestuffforbabies.net/in-a-lehman-explanation-what-are-the-main-differences-between-molecular-weight-and-formula-weight.html#comment-5811 Formula weight is used to measure ionic compounds, molecular weight to measure covalent compounds. For practical puposes in chemistry they are the same. To decide if something is ionic or covalent yoyu need to look at the electronegativeity difference >1.7 =ionic bond A rule of thumbs is that those things that are far apart onthte periodic table are bonded ionically Formula weight is used to measure ionic compounds, molecular weight to measure covalent compounds. For practical puposes in chemistry they are the same.
To decide if something is ionic or covalent yoyu need to look at the electronegativeity difference >1.7 =ionic bond
A rule of thumbs is that those things that are far apart onthte periodic table are bonded ionically

]]> http://freestuffforbabies.net/in-a-lehman-explanation-what-are-the-main-differences-between-molecular-weight-and-formula-weight.html/comment-page-1#comment-5810 Larry Wed, 30 Dec 2009 01:45:32 +0000 http://freestuffforbabies.net/in-a-lehman-explanation-what-are-the-main-differences-between-molecular-weight-and-formula-weight.html#comment-5810 Quatum physics is a mystery Quatum physics is a mystery

]]> http://freestuffforbabies.net/in-a-lehman-explanation-what-are-the-main-differences-between-molecular-weight-and-formula-weight.html/comment-page-1#comment-5809 Anonymous Tue, 29 Dec 2009 22:53:44 +0000 http://freestuffforbabies.net/in-a-lehman-explanation-what-are-the-main-differences-between-molecular-weight-and-formula-weight.html#comment-5809 Formula weight can apply to any compound whose composition can be expressed by a formula. This includes ionic compounds (e.g. NaCl), covalent giant structures (e.g. SiO2) and covalent molecular structures (e.g. CO2). The formula weight is simply the sum of the atomic weights of the atoms in the formula. Molecular weight can only be applied to compounds which exist as discrete molecules (i.e. not chemically bonded to neighbouring molecules), e.g. CO2, H2, P4O10, C2H5OH. The molecular weight is the sum of the atomic weights of each atom in one molecule. All such compounds have covalent bonds but the converse is not true - some compunds with covalent bonds do not form molecules (they form giant structures, e.g. SiO2) so they cannot be assigned a molecular weight. 'Cleveland' is correct about how to identify whether the bonding is ionic or covalent. Formula weight can apply to any compound whose composition can be expressed by a formula. This includes ionic compounds (e.g. NaCl), covalent giant structures (e.g. SiO2) and covalent molecular structures (e.g. CO2). The formula weight is simply the sum of the atomic weights of the atoms in the formula.
Molecular weight can only be applied to compounds which exist as discrete molecules (i.e. not chemically bonded to neighbouring molecules), e.g. CO2, H2, P4O10, C2H5OH. The molecular weight is the sum of the atomic weights of each atom in one molecule. All such compounds have covalent bonds but the converse is not true – some compunds with covalent bonds do not form molecules (they form giant structures, e.g. SiO2) so they cannot be assigned a molecular weight.
‘Cleveland’ is correct about how to identify whether the bonding is ionic or covalent.

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