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Feedback Q&A on Chemistry

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.

List of next 10 letters




Uses for Hydrogen How to find sulfur dioxide? Nigeria
Polar Molecules Why are hydrocarbons non-polar? Nigeria
Mixtures What is a chemical reaction? Philippines
Chemical Bonding What is the meaning of arrows? Malawi
Uses for Hydrogen Why is Helium highly inflammable? USA
Polar Molecules Why is hexane insoluble in water? Papua New Guinea
General Electrofile is used in the nitration of benzene India
Uses for Hydrogen Hydrogen used with oxygen in welding India
General Name of complex compound Pakistan
Polar Molecules I want a book of chemistry Zimbabwe

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First 10 letters

How to find sulfur dioxide?

Topic: Uses for Hydrogen


July 13, 2014

pls my question sir how can we find sulphideoxide in volcanic.? pls

aminu m - Nigeria



Sulfur dioxide has a strong odor similar to rotten eggs. There are detectors available to detect slight amounts of sulfur dioxide in the air. These can be used to tell how much is in the air near a volcano.

Note that sulfur dioxide is different than hydrogen sulfide, although both have a strong odor.

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Why are hydrocarbons non-polar?

Topic: Polar Molecules


June 30, 2014

Y are hydrocarbons non-polar

Lekan - Nigeria



Most hydrocarbons are non-polar, because they only consist of hydrogen and carbon atoms, which are both non-polar.

But in some small hydrocarbons molecules that include a polar alcohol group (OH), a small dipole moment can result thus making the hydrocarbon polar. But this is rare.

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What is a chemical reaction?

Topic: Mixtures


June 15, 2014

what is your reaction?

orvel - Philippines



In chemistry, a reaction happens when two or more molecules interact and the molecules change.

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What is the meaning of arrows?

Topic: Chemical Bonding


June 7, 2014

What is the meaning of arrows in physical science?

chifundo - Malawi



In chemical equations, such as C + O2 -> CO2, the arrow means that the combination of elements becomes the other compound.

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Why is Helium highly inflammable?

Topic: Uses for Hydrogen


May 27, 2014

why helium is highly inflamable?

bala - USA



Helium is considered an inert gas, such that it does not combine with other elements. One reason is that its outer orbit or shell is filled with two electrons. On the other hand, Hydrogen has only one electron, so it will combine with Oxygen.

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Why is hexane insoluble in water?

Topic: Polar Molecules


May 23, 2014

water is a polar solvent. why is hexane insoluble in water

Champy - Papua New Guinea



There is a rule that like substances dissolve in like substances. This means that the closer two materials are to each other chemically, the more likely they are to be soluble in each other.

Water and hexanes don't have anything in common concerning their formulas. They are too different from each other to be soluble.

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Electrofile is used in the nitration of benzene

Topic: General


April 3, 2014

which electrofile is used in the nitration of benzene.

Prashant - India



The electrophile is the "nitronium ion" NO2+.

See The Nitration of Benzene for an explanation.

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Hydrogen used with oxygen in welding

Topic: Uses for Hydrogen


April 1, 2014

Why is hydrogen used with oxygen in welding?

Debasis - India



Although hydrogen easily burns in air and can be explosive. When it is mixed with pure oxygen under controlled conditions, the flame is extremely hot and ideal for melting metal required in welding.

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Name of complex compound

Topic: General


March 28, 2014

Please help me with the IUPAC names of these complex compounds (NH4)2SO4.Fe2(SO4)3.24H2O (NH4)2SO4.Al2(SO4)3.24H2O K2SO4.Cr2(SO4)3.24H2O

What property of alum makes it useful as blood clotting agent, in fire extinguishers and in municipal water treatment

Muhammad - Pakistan



(NH4)2SO4.Fe2(SO4)3.24H2O is Ferric ammonium alum.

Alum in block form (usually potassium alum) can be used as a blood coagulant because it shrinks body tissue.

Alum is also very soluble in water.

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I want a book of chemistry

Topic: Polar Molecules


March 5, 2014

I want a book of chemistry or notes in my cellphone

Prosper - Zimbabwe



I am sorry, but I have no such book available. Feel free to use our basic lessons.

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