**Contents**show

The value of the mole is equal to the number of atoms in exactly 12 grams of pure carbon-12. 12.00 g C-12 = 1 mol C-12 atoms = 6.022 × 1023 atoms • The number of particles in 1 mole is called Avogadro’s Number (6.0221421 x 1023).

## Is a mole 12 grams?

The mole was defined by International Bureau of Weights and Measures as “the amount of substance of a system which contains as many elementary entities as there are atoms in 0.012 kilogram of carbon-12.” Thus, by that definition, one mole of pure ^{12}C had a mass of exactly 12 g.

## How do you calculate grams to moles?

Divide the mass of the substance in grams by its molecular weight. This will give you the number of moles of that substance that are in the specified mass.

## How many moles is 12 grams of o2?

Therefore, 12 g of oxygen gas has 0.375 moles.

## Why is carbon-12 the standard for moles?

To start this process, you need a mole of something. Since carbon forms millions of compounds, carbon is a good starting point. Molar mass divided by Avagadro’s number is atomic mass, especially if you are dealing with single isotopes. Again, carbon 12 is stable and easily available, so is used as a standard.

## Why carbon-12 is used in mole concept?

The reason one mole is the number of atoms in exactly 12 g of carbon-12 is that the atomic mass scale is defined by the mass of carbon-12. That is to say, one atomic mass unit is defined to be 1/12 of the mass of a carbon-12 atom.

## How many grams are in 5 moles?

Therefore, 5 moles × 32.0 g/mol = 160 grams is the mass (m) when there are 5 moles of O2 .

## How do you convert 12g of oxygen gas to moles?

Here we are given the mass of oxygen gas as 12 grams. Molar mass = 2×16 = 32 grams. We know the formula to calculate the number of moles. = 0.375 moles.

## What is equal to 1 mole?

One mole of a substance is equal to 6.022 × 10²³ units of that substance (such as atoms, molecules, or ions). The number 6.022 × 10²³ is known as Avogadro’s number or Avogadro’s constant.