How to do dimensional analysis chemistry with moles?
1 answer:
Moles are a unit of measure used to convert between different quantities like grams, molarity or volume.
Dimensional analysis is doing math with units. They multiply, divide and cancel out just like numbers. This is why like for area of a rectangle: 2m × 3m = 6m² is in units of distance squared and volume is in units of distance cubed.
Example Chemistry question.
Now, say you have 10 grams of NaCl salt that is added to 1 L water and you want to know the concentration. You would look at the periodic table and find the atomic mass of both Sodium (Na = 23 g/mol) and Chloride (Cl = 35.5 g/mol).
Once you have the atomic mass of both elements add them together to get the atomic mass of the compound NaCl = 23 g/mol + 35.5 g/mol = 58.5 g/mol
set up the multiplication so that grams cancels out during multiplication. Like so ....
Grams cancel leaving moles NaCl. The concentration of the solution, molarity = moles/liter
Divide 0.17 moles NaCl by 1 Liters = 0.17 Molarity NaCl
Hope this helps, let me know if you have any questions.
Dimensional analysis is doing math with units. They multiply, divide and cancel out just like numbers. This is why like for area of a rectangle: 2m × 3m = 6m² is in units of distance squared and volume is in units of distance cubed.
Example Chemistry question.
Now, say you have 10 grams of NaCl salt that is added to 1 L water and you want to know the concentration. You would look at the periodic table and find the atomic mass of both Sodium (Na = 23 g/mol) and Chloride (Cl = 35.5 g/mol).
Once you have the atomic mass of both elements add them together to get the atomic mass of the compound NaCl = 23 g/mol + 35.5 g/mol = 58.5 g/mol
set up the multiplication so that grams cancels out during multiplication. Like so ....
Grams cancel leaving moles NaCl. The concentration of the solution, molarity = moles/liter
Divide 0.17 moles NaCl by 1 Liters = 0.17 Molarity NaCl
Hope this helps, let me know if you have any questions.
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The question is incomplete, here is the complete question:
Problem page in each of the molecules drawn below one chemical bond is colored red. Decide whether this bond is likely to be polar or not. if the bond is likely to be polar, write down the chemical symbol for the atom which will have more negative charge.
The image is attached below.
<u>Answer:</u>
<u>For carbon dioxide molecule:</u> The bond is considered as polar and the elecvtronegative atom is oxygen.
<u>For water molecule:</u> The bond is considered as polar and the elecvtronegative atom is oxygen.
<u>Explanation:</u>
There are two types of covalent bonds:
- <u>Polar covalent bond:</u> This bond is formed when difference in electronegativity between the atoms is present. When atoms of different elements combine, it results in the formation of polar covalent bond. <u>For Example:</u>
etc..
- <u>Non-polar covalent bond:</u> This bond is formed when there is no difference in electronegativity between the atoms. When atoms of the same element combine, it results in the formation of non-polar covalent bond. <u>For Example:</u>
etc..
<u>In carbon dioxide molecule:</u>
The given bond is present between C and O atom.
Electronegativity value of C = 2.5
Electronegativity value of O = 3.5
Electronegativity difference = (3.5 - 2.5) = 1
As, electronegativity difference is present. So, the bond is considered as polar and the elecvtronegative atom is oxygen.
<u>In water molecule:</u>
The given bond is present between H and O atom.
Electronegativity value of H = 2.1
Electronegativity value of O = 3.5
Electronegativity difference = (3.5 - 2.1) = 1.4
As, electronegativity difference is present. So, the bond is considered as polar and the elecvtronegative atom is oxygen.
