August 30, 2019

A 0.050 M aqueous solution of which compound is the best conductor of electric current?

(1) C3H7OH

(2) C6H12O6 

(3) MgSO4

(4) K2SO4

Answer and Explanation:

First we need to go over what kind of compounds are the best conductors of electricity, or electrolytes.

These are: metals, ionic compounds that are molten, ionic compounds that are dissolved in water, strong acids and strong bases.  Let's now go over the compounds listed...

August 16, 2019

The Oxidation State of Nitrogen Is Most Positive In Which Compound?

This is an SAT Chemistry question from 1998 SAT Chemistry test.

a. NO3^-1

b. NO2^-1

c. N2O

d. N2

e. NH3

Answer and Explanation:

Lets first go over some rules for assigning the oxidation number.

  • Free element has an oxidation number of 0. For example, O2, Fe, Cl2 etc all have oxidation numbers of zero. Therefore, nitrogen in choice d has an oxidation number of...

August 15, 2019

3 Reasons Why It Makes Sense To Get a Tutor Ahead of Time

There is always a question of when to get a tutor. If you anticipate a difficult class and struggle, we recommend getting the tutor ahead of time. Why?

1. Getting a tutor after you didn't do well on an exam might be a little late, since you already have a bad grade on one of the exams. That means you will have to work harder and do even better on the subsequent tes...

August 13, 2019

What is the original sequence of this peptide? Solution: Since the question says that it is a nonapeptide, we know there are 9 amino acids. Sanger's reagent gives the first amino acid, and carboxypeptidase gives the last amino acid. Therefore, first amino acid of this sequence is CYS and the last amino acid is GLY.  CYS ---  --- --- --- --- --- --- GLY

August 7, 2019

Answer and Explanation: Standard deviation is a term that is used to tell how far from the mean (average) the scores lie. Whenever distribution and standard deviation is mentioned on the Regent Exam,  students need to refer to their memory of the normal distribution curve. The mean is in the middle. One standard deviation in both directions, up and down,  is 68% of the whole population. Two standard deviations in both d...

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