Exam (elaborations)
UNA Chem 101 Lab 6 Exam Graded A+
- Course
- Institution
UNA Chem 101 Lab 6 Exam Graded A+
[Show more]
Content preview
UNA Chem 101 Lab 6 Exam Graded A+A coffee drink is made by passing hot water through ground coffee beans in a coffee
maker. Is this drink a mixture? What separation technique was used in the preparation
of the drink? - ANSWER-Yes. Extraction occurs.
A sample of French fried potatoes weighing 150g was extracted with the volatile organic
solvent hexane. The recovered cooking oil weighed 12.3g. What methods from this
experiment could be used to separate and isolate the cooking oil after the extraction?
What was the percent oil in the potatoes? - ANSWER-Decantation
(12.3/150)*100 = 8.20% oil in the potatoes
Both naphthalene and para-dichlorobenzene are effective moth repellents. What
property of these chemical allow them to be used in mothballs for the protection of
wollen clothing? - ANSWER-These chemicalms undergo sublimation. The gas created
is poisonous to moths but doesn't harm clothes.
Both sublimation and evaporation bring material into the vapor phase. How do the two
methods of separation differ? - ANSWER-Sublimation goes from solid directly to gas.
Evaporation goes from liquid to gas.
Do the five methods described in the background involve physical changes or chemical
changes of matter? - ANSWER-Physical: the chemical identity of the substance stays
the same
In step 14 the sand was not completely free from water when the weight was reported.
How does this affect the percent composition of the sand in the mixture? - ANSWER-It
is increased.
In your experiment did you recover 100% of the original mixture? What was your
percent recovery? - ANSWER-No, 91.58%
Snow in the winter can slowly disappear even when the temperature is freezing. How do
you account for this observation? - ANSWER-Air temperature and ground temperature
are not the same. Sublimation occurs.
The weight of Naphthalene was obtained by weighing the collected solid. Was this an
accurate weight of the naphthalene present in the original sample? - ANSWER-No, the
experiment allows for the loss of come caffeine.
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller LUCKYSTAR2022. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $8.99. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
77254 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now