What time should I take to prepare for MCAT?

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 should take four months to six months of almost full time studying. We suggest to spend the first few weeks on review together with practice, but to dedicate the majority of time to practicing passages and questions as well as taking practice exams. MCAT is a time and energy com

Dilution Formula, general chemistry

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. When do we use this formula and how do we know that our question is a dilution question? 1. If the question itself mention the word dilute, you can use the formula. For example 20 ml of 5M solution were diluted to 59ml, what is the new Molarity? 2. If you see that in the

Monday Motivator: Journey

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 shameful! The child is sitting on the donkey like a king while his elderly father has to walk!" The child got very upset from these words and asked his father to sit on the donkey with him. A woman passing buy exclaimed: "Wow! you are torturing the animal! 2 healthy, lazy men

Child mortality rate in Mali decreases after a study

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, diarrhea, and infant sepsis. They were given in home treatment for free, and were able to survive. Study has found that many families do not bring their sick children to clinics for intervention, which leads to low survival rates. For just 8$ per person per year, child mora

Which of the following is weakly acidic?

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 acid , HBr - hydrobromic acid, HI - hydroiodic acid, HClO4 - perchloric acid, HClO3 - chloric acid. Therefore we can elimiate choice A since it is a strong acid. Strong bases are made from metals of Group 1 and 2 with OH group. Therefore, we can eliminate choice E since

Formula for Alkanes, Alkenes and Alkynes

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 double bond. Their formula is CnH2n. Thus, for example four carbon alkene will be C4H 2(4) = C4H8. Alkynes are unsaturated because they have a triple bond. Their formula is CnH2n-2. Thus, for example four carbon alkyne will be C4H 2(4)-2 = C4H6. Organic Chemistry is a fascina

SAT Chemistry overview

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. To be well prepared for the test, a student has to take 1 year of introductory college level chemistry (general chemistry). Content of the Test: Structure of matter Atomic Structure, including experimental evidence of atomic structure, quantum numbers and energy levels (orbi

What does a cell nucleus contain?

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. Thus, RNA is also found in the nucleus. After it is formed, it oftentimes, gets modified and then goes outside of nucleus through the nuclear pores. RNA, can then start translation (process of creation of proteins from RNA template). To learn more biology with our fantastic bi

Leafs and roots

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 store. This was a very sad time. This man decided to built a new store and needed to borrow money for it. He went to the bank but the bank refused to give it to him. His friends also turned away. Then he received a letter from him father telling him that he heard about his misfortunes and wa

Acidity across the group and period

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 fluorine. Therefore, HI is most acidic, followed by HCl and HF is the least acidic. Rule 2: For compounds containing elements in the same period, acidity increases with increasing electronegativity (left to right). For example lets compare the acidity of H2O, HF and NH3. Nitrogen,

Practice makes perfect

Many students oftentimes are not sure what their strategy should be for studying for standardized exams, science and math classes. My answer is always practice, practice and practice more. A student should practice all the quizzes, tests, HW and classwork problems the teacher gave, as well as end of the chapter problems. For standardized tests, use different sources for practice to see different wording of questions on the same topic. Pay most attention to the practice sources that come from the company that actually makes the test you would take, such as College Board for SAT, and AAMC for MCAT. When practicing, go one problem at a time. Do the problem by yourself and then look at the answe

How to reduce anxiety during finals times?

College can be very stressful and bring anxiety with the never ending papers and tests. So how do you ease your anxiety and prepare for the tests? 1. Make a list of tasks that need to be done in order of priority. Seeing an organized list will help you feel less overwhelmed and get prepared ahead of time. 2. Make a to-do list everyday. 3. Reward yourself for every task accomplished. This could a yummy dinner, a nice walk, or a hangout with a friend. 4. Take a 30 mins break every day to relax and meditate. Your mental and physical health are most important. 5. Visualize your success in the morning. Every morning visualize your success and keep a journal of your accomplishments. Learn from you

What is the number of moles of KF in a 29-gram sample of the compound?

What is the number of moles of KF in a 29-gram sample of the compound? (1) 1.0 mol (2) 2.0 mol (3) 0.50 mol (4) 5.0 mol Answer and Solution: To find the number of moles, you can look at the reference table Table T and find the formula for moles. Number of moles = given mass/ gram-formula mass Therefore let's use first fine the gram formula mass by looking at the periodic table. K has a mass of 39g/mol and F is 18.998 g/mol. Therefore mass of KF = 39+18.998 = 57.998g/mol this formula : Number of moles = 29g (mass given in the problem) / 57.998 g/mol = 0.5 moles Choice 3 is the correct choice. Let's have fun in chemistry and let our amazing chemistry tutors in NYC and online help you ace your

Which statement describes the location of 5 protons and neutrons in an atom of helium?

Which statement describes the location of 5 protons and neutrons in an atom of helium? Protons and neutrons are in the nucleus. Protons and neutrons are outside the nucleus. Protons are outside the nucleus, and neutrons are in the nucleus. Protons are in the nucleus, and neutrons are outside the nucleus. Answer and Explanation: There are three subatomic particles students should be familiar with: protons, neutrons and electrons. Both protons and neutrons are located inside the nucleus making it positively charged and therefore choice 1 as the correct answer choice. Electrons, on the other hand, are located outside the nucleus and are negatively charged. To learn more chemistry with the best