If 45.1 grams of a solute is added to 302 grams of water to make a 0.65M solution, what is the molar mass of a solute?
Correct Answer: E.(45.1 grams)/(0.65(.302)moles)
To determine the molar mass, the molarity equation will be needed.
Molarity = (moles of solute)/(Liters of solution)
Plugging in the values from the problem results in:
0.65 = (moles of solute)/(.302 L)
Note: The amount of the solution is given in terms of grams of water, this can be converted to mL by using the density of water (1.0 grams/mL) and then converting the mL into liters. Cross-multiplying gives the following:
0.65(.302) = moles of solute
The molar mass of a compound is in grams per mole. Therefore the molar mass of the unknown solute would be 45.1 grams of solute (from the question) divided by the number of moles just calculated 0.65(.302). Putting the pieces together results in a molar mass of the unknown solute of:
Subscribe below to get the DAT Question of the Day delivered straight to your inbox every morning.
The Dental Admission Test (DAT) is a test administered by the American Dental Association (ADA). The test is four hours and 30 minutes long and contains four sections. The test is designed to assess your knowledge in: biology, chemistry, organic chemistry, perceptual ability, reading comprehension, and basic math.
How Should I Study?
The DAT is the final challenge before you apply to dental school and should not be taken lightly. Depending on the strength of your scientific knowledge, your study schedule should be between 4 to 10 weeks. Here's a link to my definitive DAT study guide and schedule which will help you prepare.
Register for the DAT.
You should plan on taking the DAT late spring or during the summer of your application year. For example, the class of 2020 should take the DAT in the spring or summer of 2015. You can begin the registration process for the DAT at the ADA's website. Be sure to apply for a test date early as the registration process may take some time.