Skip to main content

Explain these three measures of moles: (mass/Mr), (concentration/vol) and (volume/24).

One can think about a mole as a measure of mass or quantity of a substance. A mole of a substance contains 6.023 x 10^23 atoms (or molecules, if the substance is a compound). That is to say, one mole of the element iron contains 6.023 x 10^23 atoms of iron, while one mole of oxygen gas consists of 6.023 x 10^23 molecules of oxygen gas. One can obtain the moles of a substance by...

One can think about a mole as a measure of mass or quantity of a substance. A mole of a substance contains 6.023 x 10^23 atoms (or molecules, if the substance is a compound). That is to say, one mole of the element iron contains 6.023 x 10^23 atoms of iron, while one mole of oxygen gas consists of 6.023 x 10^23 molecules of oxygen gas. One can obtain the moles of a substance by using the three formulas your teacher mentioned:


  • The number of moles of a substance is the ratio of the mass of a substance and its molar mass or Mass/Mr. For example, water (H2O) has a molar mass of 18 g, thus, 50 g of water contains 50 g /18 g = 2.78 moles of water.

  • The concentration of a solution is often expressed in terms of molarity, which is the ratio of moles of solute to volume of solution. Thus, the number of moles of a solute can be calculated as the product of molarity and volume. For example, 1 lt of 2 molar solution of sulfuric acid contains 1 l x 2 M = 2 moles of acid.

  • One mole of a gas occupies 24 lt volume at room temperature, thus the moles of a gas can be calculated as the ratio of volume (in lt) to 24. That is, moles = volume/24.

Thus, the three formula mentioned by your teacher will help you calculate the moles of solids, liquids and gases.


Hope this helps.  

Popular posts from this blog

In chapter one of The Great Gatsby, what advice does Nick's father give him? How does this make him a good person to tell this story?

Nick says that his father advised him that, before "criticizing anyone," he "remember that all the people in this world haven't had the same advantages" as Nick.  As a result, Nick claims that he is "inclined to reserve all judgments," presenting himself to the reader as a fair and dispassionate arbiter of character, and thus, a reliable narrator.   The problem is that Nick immediately reveals himself as anything but reliable, as he then launches... Nick says that his father advised him that, before "criticizing anyone," he "remember that all the people in this world haven't had the same advantages" as Nick.  As a result, Nick claims that he is "inclined to reserve all judgments," presenting himself to the reader as a fair and dispassionate arbiter of character, and thus, a reliable narrator.   The problem is that Nick immediately reveals himself as anything but reliable, as he then launches into a discussion of how pe...
Post a Comment
Read more

How and why does James Gatz become Jay Gatsby? Describe the young Gatsby/Gatz.

James Gatz, a poor Midwestern boy of probable Jewish lineage, becomes Jay Gatsby, a presumed WASP and wealthy socialite, when he moves to New York City and acquires his fortune. It is wealth that has allowed Gatz to transform himself into Gatsby. However, those who know his background (e.g., Daisy and Tom Buchanan) never allow him to forget that he is nouveau riche -- that is, an upstart who has just recently made his fortune,... James Gatz, a poor Midwestern boy of probable Jewish lineage, becomes Jay Gatsby, a presumed WASP and wealthy socialite, when he moves to New York City and acquires his fortune. It is wealth that has allowed Gatz to transform himself into Gatsby. However, those who know his background (e.g., Daisy and Tom Buchanan) never allow him to forget that he is nouveau riche -- that is, an upstart who has just recently made his fortune, whereas they arose from well-to-do families. Gatz became Gatsby through determination and discipline. At the end of the novel, the narr...
Post a Comment
Read more

Explain and discuss how the definitions of freedom change for the nation, for the freedmen and for southern whites after the Civil War.

After the Civil War, the definition of freedom changed in the nation, as slavery was ended with the 13th Amendment to the Constitution in 1865. The practice of slavery was disallowed, but definition of the freedom that would take its place was a subject of controversy, ongoing debate, and even violence in the decades to come.  For freedmen, freedom often meant reconciling with their families, who were broken up by slavery; choosing which church to... After the Civil War, the definition of freedom changed in the nation, as slavery was ended with the 13th Amendment to the Constitution in 1865. The practice of slavery was disallowed, but definition of the freedom that would take its place was a subject of controversy, ongoing debate, and even violence in the decades to come.  For freedmen, freedom often meant reconciling with their families, who were broken up by slavery; choosing which church to belong to without being ordered to attend religious services (or not to attend) by their mast...
Post a Comment
Read more