by Ron Kurtus
Readers have sent in a total of 545 comments and questions on Chemistry issues. They are listed according to date.
You can read them to further your understanding of the subject.
|Azeotropic Mixture||Order of Elements in a Formula||Nigeria|
|Why does an apple change color when cut open?||General||India|
|Why is nitrogen used in tires?||Uses of Nitrogen||USA|
|Microwaves and polar molecules||Polar Molecules||India|
|Define Electronegativity matter||Polar Molecules||Ethiopia|
|About Nitrogen||Uses of Nitrogen||Philippines|
|Examples of liquid non-polar compounds||Polar Molecules||India|
|Why is oxygen classified as non-polar?||Polar Molecules||Namibia|
|Use of arrow sign in chemical reaction||Chemical Equations||India|
|Can I used compressed nitrogen to paint a boat?||Uses of Nitrogen||USA|
|Solids used to obtain oxygen gas||Oxygen||Kenya|
|How is CO2 non-polar?||Polar Molecules||Namibia|
|Questions for science project||Uses of Nitrogen||USA|
|Correction in formula||Order of Elements in a Formula||USA|
|Why do nonpolar solutes tend to adhere||Polar Molecules||China|
October 27, 2017
Whats Azeotropic Mixture
Saviour - Nigeria (28301)
An Azeotropic Mixture is known as a constant boiling point mixture. That means the mixture cannot be separated by boiling or distillation. An example of such a mixture is 5% water and 95% ethanol.
Why does an apple change color when cut open?
June 9, 2017
Why apple turns into red colour after cutting into slides?
Maddakam - India (28081)
Apples start to oxidize once they are cut open. That is the reason the colour changes.
Why is nitrogen used in tires?
May 28, 2017
Why is it used in tires?
Allen - USA (28064)
Air is made up of 78% nitrogen, so it is already in inflated tires. Pure nitrogen has the advantage of keeping a more stable pressure in the tires over a long run. Race cars use pure nitrogen to avoid pressure changes when the tires heat up during a race.
Microwaves and polar molecules
March 31, 2017
Why polar molecule are microwave active
saurabh - India (27975)
Microwave ovens work by causing polar molecules to spin rapidly and thus heat up the material. The wavelength of the microwave is such that its frequency or change in direction works well in causing the polar molecules to rotate. Non-polar molecules are not really affected by the microwave radiation.
Define Electronegativity matter
December 6, 2016
Define Electron Negativity matter on polarity and non polarity
Fanuel - Ethiopia (27533)
Electronegativity is a measure of the tendency of an atom to attract a bonding pair of electrons. Using the Electronegativities we can predict whether a given bond will be non-polar, polar covalent, or ionic. The greater the difference in electronegativity the more polar the bond.
See Bond Polarity and Polar vs Non-Polar Molecules for more information.
I hope that helps
August 11, 2016
Nitrogen physical properties,origin,characteristics and uses?
Noel - Philippines (27203)
Examples of liquid non-polar compounds
July 10, 2016
Example of liquid non polar compounds.
Raman - India (27142)
Oils, including vegetable oil and related products like gasoline, are the most common examples of non-polar liquids.
Why is oxygen classified as non-polar?
June 25, 2016
why oxgyen is classfied as non polar and carbon dioxide polar ?
Johannes - Namibia (27105)
Whether a molecule is polar or non-polar depends on its geometry. Oxygen exists as a molecule of two oxygen atoms. The combination balances the distribution of their electrons.
Carbon dioxide is also a non-polar gas for the same reason.
Use of arrow sign in chemical reaction
May 16, 2016
Some of the chemical reactions are represented by arrow sign and some are by equal sign. What is the difference between this two types?
Mohammad - India (27008)
If the chemical reaction mainly goes in one direction, it is represented by an arrow to indication the direction. For example C + O2 --> CO2.
Some reactions can readily go in both directions and are represented by a double arrow ( <---> ) or an equals sign.
Can I used compressed nitrogen to paint a boat?
April 29, 2016
Hey there, I am Nelson from Nautiques Boat Care. My question is can I use it nitrogen as a substitute to regular air pressure when I spray the paint or gel coat to avoid moisture?
Jose - USA (26971)
Since air is made up of 80% nitrogen, using compressed nitrogen to spray the paint. Besides nitrogen and oxygen, air also includes water vapor.
However, compressed nitrogen probably would be more expensive than compressed.
Solids used to obtain oxygen gas
April 27, 2016
Name two solids that can be heated to obtain oxygen gas.
Engneer - Kenya (26969)
Mercuric oxide (HgO), potassium chlorate (KClO3), and sodium peroxide (Na2O2)
How is CO2 non-polar?
April 13, 2016
Why do we say Carbondioxide gas is a non-polar in terms of charges on it. It seems like oxygen has more electrons than carbon in gas. I am confused help me please.
Mweneni - Namibia (26927)
The atoms in carbon dioxide (CO2) are arranged in a line, with the oxygen atoms on the outside. This makes the distribution of charges symmetrical, making the gas molecules non-polar.
See the illustration of CO2 in Polar and Non-Polar Molecules. I hope that helps you understand the concept.
Questions for science project
April 9, 2016
Hi, my name is Jennifer. I am emailing you because this is for my science class project and my subject was on nitrogen. And just wondering if you could answer at least two questions for me. Q1: Is nitrogen good or bad for you? Q2: when was nitrogen discovered for these uses? Please answer ASAP, please and thank you. Thank you for your time to email this!
Jennifer - USA (26918)
Since nitrogen makes up about 78% of the air you breathe, it certainly is not bad for you. What makes it good for you is that it makes sure you don't get too much oxygen at once.
Nitrogen is a key component of biological molecules such as proteins (which are made from amino acids, and nucleic acids. The nitrogen cycle in nature is very important.
Nitrogen was discovered by Daniel Rutherford in 1772 at Scotland.
I hope that helps. Best wishes for success in your science project.
Correction in formula
January 28, 2016
On your page regarding the order of elements in a chemical formula, you made the following statement:
"Most oxides will end in multiples of O, no matter what the alphabetical order. A good example is silicon dioxide: SO2"
However, I would just like to point out this (referring to the EXAMPLE) is wrong - I don't know if you are trying to refer to sulfur dioxide or SiO2. Just wanted to let you know so you could fix it! By the way, your page is amazing, super-informative and really helps me - thank you so much!
Shada - USA (26727)
Thanks for letting me know about that typo. I corrected the formula to be SiO2 in the Order of Elements in a Chemical Formula page.
I'm also glad the material has been useful to you.
Best wishes in your studies.
Why do nonpolar solutes tend to adhere
January 9, 2016
I have a question
Explain why two nonpolar solutes (or nonpolar groups) tend to adhere to each other in aqueous solutions
qun - China (26673)
This is known as the hydrophobic effect, where nonpolar substances to aggregate in aqueous solution and exclude water molecules. This occurs because interactions between the hydrophobic molecules enable the displaced water molecules to make hydrogen bonds more freely with each other and increase the number of hydrogen bonds they are involved with, thereby decreasing the overall free energy.
I hope that answers your question.
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