March 30, 2018

MCAT , or medical college admissions test, is a hard and lengthy (7.5 hour) test taken by students to apply to medical schools. MCAT covers a great deal of subjects including general chemistry, organic chemistry, physics, biology, biochemistry, psychology, sociology, math (no calculator is allowed for science calculations), and reading comprehension. Due to the scope of the topics, to prepare for this exam, a student sh...

March 28, 2018

Dilution is a common type of problems given to students in the concentration chapter of their chemistry class. To dilute something means to add water to the solution, which will in turn decrease the concentration.

The formula for dilution is M1V1= M2V2

where M1= Molarity 1 

V1 = Volume 1

M2 = Final Molarity

V2= Final Volume

Note, that for this formula your volume can be in any units as long as it is consistent on both sides.

W...

March 26, 2018

The journey 

One day a son and father were traveling to the neighboring city. Son was walking next to the donkey while the father was sitting on the donkey. "Poor boy" : a man passing by said, "His small feet can barely walk while the father is sitting comfortably on the donkey." Hearing this, the father got off the donkey and put his son on the donkey instead of him. As he was walking, another man passed by saying " How...

March 23, 2018

A seven year project between US and Mali has ended recently with astonishing results. Under five child mortality decreased from 154deaths per 1000 children to 7 per 1000 children.  This study suggests that for small amounts of money, child mortality can be decreased drastically and thousands of lives could be saved.

How was it done? Health workers would go to houses checking on children who has symptoms such as pneumonia...

March 22, 2018

SAT II Chemistry practice question.

Topic: Acids and Bases

Which of the following is weakly acidic?

a. 0.1M HCl

b. 0.1M NaCl

c. 0.1M HC2H3O2

d. 0.1M CH3OH

e.  0.1M KOH

Solution: In order for us to answer this question we must know how to identify strong acids and strong bases. We have to memorize strong acids in order to be able to identify them. Strong acids are: HCl - hydrochloric acid, HNO3 - nitric acid, H2SO4 - sulfuric ac...

March 20, 2018

Organic Chemistry formulas:

Alkanes, alkenes and alkynes are three classes belonging to the hydrocarbon homologues series. These are organic compounds that are composed of carbon and hydrogen as their name implies. 

Alkanes have only single bonds, and are therefore saturated hydrocarbons. Their formula is CnH2n+2. Thus, for example four carbon alkane will be C4H 2(4)+2 = C4H10

Alkenes are unsaturated because they have a do...

March 19, 2018

SAT subject test in  Chemistry is administered by College Board. 

Time: The test is 60 minutes long

Number of questions: 85 multiple choice questions

Calculator: Not Allowed

Periodic table that indicated atomic numbers and masses is provided on the test.

Test Dates: Test is offered in August, October, November, December, May, and June.

Practice: College board released 2 official tests that can be purchases on its website...

March 14, 2018

A cell nucleus is a membrane enclosed organelle found in eukaryotic cells. Nucleus contains all of the genetic information a cell has, in the form of DNA. It also contains various proteins. For example proteins, histones, are what DNA strands wrap around to form chromosomes. Furthermore, both DNA replication as well as transcription happens in the nucleus. Transcription is the process of creating RNA from DNA template....

March 13, 2018

A long time ago, there lived a rich man who had a shop. Every month he would send money to his parents, and even presents on holidays. However, no matter how much they asked him to come visit, he never did. He was always so busy with working and  seeing his friends, and so he never had time to come home. 

One day, this man's shop burned down. All of his products and everything he had, burned down with the...

March 13, 2018

How do we compare substances in terms of acidity?

Rule 1: For binary acids with elements in the same group, acidity increases as we go down the group (with increasing radius). For example lets compare, HCl, HF and HI. First we notice that Cl,F, and I are all in the same group, Group17. Therefore we can now compare elements in terms of their radius. Iodine has the largest radius (most down) followed by chlorine and fluori...

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