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# Calculate concentrations in air, water and octanol (answer)

Did the person who wrote this problem even try solving it?  It's actually not solvable with the information given.  When I tried it, I actually got more xylene than is actually present, when I added the three amounts together. Partly, this is because you were given the wrong Henry's...

Oops.  Did it again.  That should have been added as an answer, rather than a comment.  Too bad I can't remove, or even edit my comment.

# how does the octet rule applies to covalent bonds? (answer)

The octet rule isn't really a reason why.  It's simply an observation as to what happens.  The full answer is rather complex, but it mainly amounts to two properties:  ionization energy (how much energy it takes to remove an electron) and electron affinity (the ability to gain...

# what is a secondary carbon? (answer)

Correct answer:  None of the above Probable expected answer:  benzene As Daniel stated, a secondary carbon has two adjacent carbons (benzene is the only one that fits). However, there is another aspect of the definition, in that the term is only used for tetrahedral (sp3) carbons...

# ATOMIC MASS vs MASS NUMBER (answer)

The mass number is not the same as the mass of the atom. The mass number is obtained by counting the number of protons and neutrons. Each proton and neutron is approximately 1 u, but not exactly.  Also, in atoms, the total is not the sum of the parts.  A small amount of mass...

# Is this true or not (answer)

What, exactly, are you asking? Is what true? This is very convoluted. There are errors in the calculations above: line 2, the mass of an atom of Li is 6.94 u, but close enough line 7, remove the "kg" from the end. line 9, put parentheses around the denominator, otherwise...

# Consider the titration of 300.0 mL of 0.500 M NH3 (Kb = 1.8 ×10-5) with 0.500 M HNO3. At the stoichiometric point of this titration the pH is? (answer)

The first answer is incorrect.  At the stoichiometric point, the concentration of the NH3 is almost zero (all of the NH3 has reacted with H+).  To a first approximation, it is zero.  All that's present is NH4+ (plus the NO3- spectator ions, which we'll ignore).  Since...

# Why is it that when you put an empty container upside down on a surface with water, does it become suctioned ? (answer)

Here are two other aspects to this phenomenon. The "seal" referred to above is caused by the fact that water is attracted to both the surface and the glass.  When you attempt to lift the glass, the water seal is kept in place initially.  When this happens, you are attempting...

# what is the covalent bond for Nitogen and Fluride (answer)

Can you clarify the question?

## Units of Temperature

One mistake that I see time and time again is the use of degrees Celsius when performing calculations in chemistry class. The problem with this is that there are no properties are directly proportional to the Celsius temperature. Let's look at gas volume as an example. Charles' Law states that the volume of a gas is directly proportional to the temperature of that gas. If you could use the... read more

## Introduction

I've started a couple of blogs before, so I thought I would start one here that relates to tutoring. I'll be posting tips on how to succeed in chemistry (and related subjects, such as physics). Topics that I plan on covering include, in no particular order: - Unit Analysis - Units of Temperature - Heat Capacity - How to figure out if an energy difference should be positive... read more