Chemistry is one of the first classes you’ll take as a premed and it shows on the MCAT. Today we’ll cover some foundational topics related to chemistry.
Once again, Bryan of Blueprint MCAT (formerly Next Step Test Prep) is joining us as always. And by the way, don’t forget to check out all our other podcasts on MedEd Media.
This time, we’re doing General Chemistry so we’re going to the real basics – the atoms and compounds. By basic, it doesn’t mean it’s easy. These questions can still be tricky. They do require that you have mastered the fundamentals. That said, start by mastering the periodic table.
“The MCAT is a mile wide and an inch deep, but you really have to master that inch of depth that it has.”
Question 5: Which of the following statements are true of CO2:
III. Seven moles of it contain 3.5 moles of oxygen
Answer choices:
Remember the definitions and this is true in all of MCAT. Make sure you understand and remember all of the definitions. First, a molecule is anything that’s multiple atoms stapled together. So O2 is a molecule. A polymer of esters and a single molecule can be three feet long but that’s still a molecule, anytime you stitch atoms together. For CO2, we stitched together three atoms that’s a molecule. So I. is correct.
A compound is a type of molecule that’s multiple so there are different kinds of atoms. O2 is an oxygen is a molecule, but not a compound. It’s just oxygen. Whereas CO2 is carbon and oxygen atoms so that’s a compound. So II. is also true.
So the answer here is (A). And you’re done!
Question 7: Of these options, the elements that would form a bond with the least ionic character are:
When remembering ionic and covalent molecules, the ionic ones are those that happen when a molecule or atom gives its electron to its neighbor. And then they’re held together by electrostatics. So in table salt (NaCl), sodium gives out its electron and becomes Na+ and gives its electron to the Chlorine atom, making a Cl-. And then plus and minus 1, stick together and that’s how a table salt sticks together.
Covalent, on the other hand, refers to the sharing of electrons. Now the question said least ionic, so mostly kind of covalent.
The way to figure this out is looking at where the atoms are situated on the periodic table. Atoms that are far apart, all the way to the left and all the way to the right are going to be more likely to be ionic. And the atoms right next to each other in the periodic table are more likely to be covalent. If they’re next to each other and certainly if they’re in the same column, then that means they have similar behavior. So when they’re together, they’re going to want to share.
On the MCAT itself, you would have a periodic table, but you should be familiar enough with the periodic table to recognize that as you’re reading those answer choices, the very first choice, N and O are right next to each other on the periodic table. So when they form a bond, it is a polar covalent, but still covalent bond which as the least ionic character.
When you want to check the periodic table on the MCAT, it’s found on the upper right hand corner of the screen.
Question 8: A particular element overwhelmingly prefers to form one bond and possess three lone pairs. Which group does this species likely belong in?
This group would more likely be the halogens. This would be relatively straightforward once you recognize that description of halogens. You can just open the periodic table and look at what group it is and halogens are group 17.
Don’t forget to check out Blueprint MCAT (formerly Next Step Test Prep). They’re online full length practice exams have just been revamped to match the new user interface that the AAMC and Pearson has ruled out for the MCAT. Use the promo code MCATPOD to save some money.
Lorem ipsum dolor sit amet, consectetur adipiscing elit
I just received my admission to XXXXX! This is unreal and almost feels like I am dreaming. I want to thank you for all of your help with my application. I cannot overstate how influential your guidance and insight have been with this result and I am eternally grateful for your support!
IM SO HAPPY!!!! THANK YOU SO MUCH FOR ALL YOUR HELP, IM INDEBTED TO YOU! Truly, thank you so much for all your help. Thank you doesnt do enough.
I want to take a few moments and thank you for all of your very instructive, kind and consistent feedback and support through my applications and it is your wishes, feedback, and most importantly your blessings that have landed me the acceptance!
I got into XXXXX this morning!!!! It still has not hit me that I will be a doctor now!! Thank you for all your help, your words and motivation have brought me to this point.
I wanted to once again express my heartfelt gratitude for your help in providing feedback during my secondary applications. Your guidance has been instrumental in my journey.
Just wanted to share my wonderful news! I received my first medical school acceptance! Thank you for all that you do for us Application Academy!!!
I am excited to tell you that I just got my third interview invite from XXXXX today! I can’t believe it. I didn’t even know if I was good enough to get one, let alone three – by mid-September. Thank you so much for all of your help and support up to this point; I would not be in this position without it!!
I wanted to thank you for helping me prepare for my XXXXX interview. Even in a 30-minute advising session, I learned so much from you. Thank you for believing in me, and here’s to another potential success story from one of your advisees!
I just received an acceptance with XXXXX! This is so exciting and such a huge relief and so nice to have one of our top choice schools! I also received an interview with XXXXX which brings the total up to 20 interviews! Thank so much, none of this would have been possible without you!
Join our newsletter to stay up to date
* By subscribing you agree to with our Privacy Policy and provide consent to receive updates from our company.
Resources
Advising Services
Podcasts & Youtube
Books
About
