Relative Atomic Mass Of Carbon

Molar mass of NaHCO3 = 84.00661 g/mol

Dress sketch. This compound is also known as Baking Soda or Sodium Bicarbonate.

Convert grams NaHCO3 to moles or moles NaHCO3 to grams

Mass numbers of typical isotopes of Carbon are 12; 13. Atomic Mass of Carbon. Atomic mass of Carbon is 12.0107 u. The atomic mass is the mass of an atom. The atomic mass or relative isotopic mass refers to the mass of a single particle, and therefore is tied to a certain specific isotope of an element. Relative atomic mass = average mass of an atom/mass of carbon-12 x (1/12) The average mass of an atom is calculated using the masses of different isotopes of an element and their abundance. The value of one twelfth of mass of carbon-12 isotope is 1.66054 x 10 -18 g. ››More information on molar mass and molecular weight. In chemistry, the formula weight is a quantity computed by multiplying the atomic weight (in atomic mass units) of each element in a chemical formula by the number of atoms of that element present in the formula, then adding all of these products together.

What is the atomic mass of carbon

Molecular weight calculation:
22.98977 + 1.00794 + 12.0107 + 15.9994*3


Symbol# of AtomsSodiumNa22.989770127.367%
HydrogenH1.0079411.200%
CarbonC12.0107114.297%
OxygenO15.9994357.136%


Note that all formulas are case-sensitive.Did you mean to find the molecular weight of one of these similar formulas?
NaHCO3
NaHCo3


In chemistry, the formula weight is a quantity computed by multiplying the atomic weight (in atomic mass units) of each element in a chemical formula by the number of atoms of that element present in the formula, then adding all of these products together.

Using the chemical formula of the compound and the periodic table of elements, we can add up the atomic weights and calculate molecular weight of the substance.

If the formula used in calculating molar mass is the molecular formula, the formula weight computed is the molecular weight. The percentage by weight of any atom or group of atoms in a compound can be computed by dividing the total weight of the atom (or group of atoms) in the formula by the formula weight and multiplying by 100.

A common request on this site is to convert grams to moles. To complete this calculation, you have to know what substance you are trying to convert. The reason is that the molar mass of the substance affects the conversion. This site explains how to find molar mass.

Formula weights are especially useful in determining the relative weights of reagents and products in a chemical reaction. These relative weights computed from the chemical equation are sometimes called equation weights.

Finding molar mass starts with units of grams per mole (g/mol). When calculating molecular weight of a chemical compound, it tells us how many grams are in one mole of that substance. The formula weight is simply the weight in atomic mass units of all the atoms in a given formula.

The atomic weights used on this site come from NIST, the National Institute of Standards and Technology. We use the most common isotopes. This is how to calculate molar mass (average molecular weight), which is based on isotropically weighted averages. This is not the same as molecular mass, which is the mass of a single molecule of well-defined isotopes. For bulk stoichiometric calculations, we are usually determining molar mass, which may also be called standard atomic weight or average atomic mass.

Main Difference – Relative Atomic Mass vs Atomic Mass

Atoms are the basic units of matter. Scientific discoveries have revealed that an atom can be further divided into subatomic particles: electrons, protons, and neutrons. It was also discovered that an atom has a complex structure with a central core, named nucleus and electrons moving around this nucleus. The nucleus contains protons and neutrons. Relative atomic mass and atomic mass are two chemical terms that are used to express the mass of an atom. The main difference between relative atomic mass and atomic mass is that relative atomic mass is the ratio of the average mass of atoms of an element to one twelfth of the mass of carbon-12 whereas atomic mass is the total mass of nucleons present in the nucleus of an atom.

Key Areas Covered

1. What is Relative Atomic Mass
– Definition, Calculation, Example
2. What is Atomic Mass
– Definition, Calculation, Example
3. What is the Difference Between Relative Atomic Mass and Atomic Mass
– Comparison of Key Differences

Key Terms: Atom, Atomic Mass, Electrons, Neutrons, Nucleus, Protons, Relative Atomic Mass

What is Relative Atomic Mass

Relative atomic mass is the ratio of the average mass of atoms of an element to one twelfth of the mass of carbon-12. One twelfth of the mass of an atom of carbon-12 is named as atomic mass unit (1 amu or 1 u). Hence, the relative atomic mass of carbon-12 is 12 amu.

Relative atomic mass = average mass of an atom/mass of carbon-12 x (1/12)

The average mass of an atom is calculated using the masses of different isotopes of an element and their abundance. The value of one twelfth of mass of carbon-12 isotope is 1.66054 x 10-18g. It is equal to 1 u or one unified atomic mass unit. Let’s consider a hydrogen atom and calculate the relative atomic mass.

Relative Atomic Mass of Hydrogen

First, we need to find the average mass of a hydrogen atom.

Relative atomic mass of carbon

Isotope

Abundance (%)

Mass (u)

Hydrogen-1

99.98

1.007825

Hydrogen-2

0.02

2.014101

Hydrogen-3

Trace

‎3.016049

Average mass of hydrogen = (1.007825 u x 99.98%) + (2.014101 u x0.02 %)
= (1.007623 + 0.0000402) u
= 1.0076632 u

The value of one twelfth of the mass of carbon-12 isotope is 1 u.

Therefore,

Relative atomic mass = average mass of an atom/mass of carbon-12 x (1/12)
= 1.0076632 u / 1 u
= 1.0076632

Here, the mass of tritium was not included in the calculation because its abundance is trace in the environment and is negligible. The final value is dimensionless because it is a relative value.

What is Atomic Mass

Atomic mass is the total mass of nucleons present in the nucleus of an atom. A nucleon is either a proton or a neutron. Hence, atomic mass is the total mass of the proton and neutrons present in the nucleus. Although electrons are also present in atoms, the mass of electrons is not used in the calculations because electrons are so small and have a negligible mass when compared to protons and neutrons.

Unlike in relative atomic mass, here we calculate the mass of each and every atom without calculating any average value. Therefore, we get different values for atomic masses of different isotopes. That is because the number of nucleons present in isotopes of the same element is different from each other.

Let us consider the same example as for relative atomic mass; hydrogen.

Atomic Mass of Hydrogen-2

The atomic mass of hydrogen-2 (Deuterium) isotope is calculated as follows.

The number of protons in the nucleus = 1
The number of neutrons in the nucleus = 1
Atomic mass of hydrogen = (1 amu +1 amu)
= 2 amu

The atomic mass is given by the unit amu (atomic mass units). One protons or a neutron has a mass of 1 amu.

Difference Between Relative Atomic Mass and Atomic Mass

Definition

Relative Atomic Mass: Relative atomic mass is the ratio between the average mass of atoms of an element to one twelfth of the mass of carbon-12.

Atomic Mass:Atomic mass is the total mass of nucleons present in the nucleus of an atom.

Isotopes

Relative Atomic Mass: Relative atomic mass is calculated using the masses and the percentage abundance of all the isotopes of an element.

Atomic Mass:Atomic mass is calculated for each and every isotope separately by adding masses of nucleons.

Value

Relative Atomic Mass: The value of Relative atomic mass is obtained relative to the one twelfth of the mass of the carbon-12 atom.

Atomic Mass:The value of atomic mass is a directly calculated value (not a relative value).

Unit

Relative Atomic Mass:Relative atomic mass is dimensionless because it is a relative value.

Atomic Mass:Atomic mass is given by unit amu.

Conclusion

Atomic mass and relative atomic mass are two important chemical terms. Although they sound similar, the concepts are different. The main difference between relative atomic mass and atomic mass is that relative atomic mass is the ratio of the average mass of atoms of an element to one twelfth of the mass of carbon-12 whereas atomic mass is the total mass of nucleons present in the nucleus of an atom.

What Is The Atomic Mass Of Carbon

References:

Relative Atomic Mass Of Carbon Dioxide

1. “Relative atomic mass.” Wikipedia, Wikimedia Foundation, 26 Oct. 2017, Available here.
2. “Atomic Mass.” Merriam-Webster, Merriam-Webster, Available here.
3. wikiHow. “How to Calculate Atomic Mass.” WikiHow, WikiHow, 5 Oct. 2017, Available here.

Image Courtesy:

Definition Of Relative Atomic Mass

1. “204 Isotopes of Hydrogen-01” By OpenStax College – Anatomy & Physiology, Connexions Web site, Jun 19, 2013. (CC BY 3.0) via Commons Wikimedia
2. “Blausen 0527 Hydrogen-2 Deuterium” By BruceBlaus – Own work (CC BY 3.0) via Commons Wikimedia