Chem Homework

[04jstewa]

Howdy! I am currently taking Chem 1 in College and having trouble remembering extacly how to convert units into certain units. I was wandering if you guys could check these few problems for me and help me with 2 if you are bored. I don't expect ya to do the work for me but point me in the direction if possible. Also, if you know a great converting chart I could learn or a website that would build my confidence in converting, I would be most greatful. This problems are very simple, its just, it has been nearly 5 years since I have done any sort of coverting with grams, mL etc. Thanks in Advance :)

Problem 1

An unhealthy person has about 206mg of cholesterol per 100. mL of blood. If the total blood volume of that individual is 5.22L, how many grams of total blood of cholesterol does the individual contain?
Enter scientific notation as 1.23E4.

My answer: 10.7532g (This right?)

Problem 2

A 37.53 g sample of a solid is placed in a flask. Toluene, in which the solid is insoluble, is added to the flask so that the total volume of completely submerged solid and liquid together is 65.96 mL. The solid and toluene together have a mass of 83.68 g. The density of toluene at the temperature of the experiment is 0.9886 g/mL. What is the density of the solid in g/cm3?
Enter scientific notation as 1.23E4.

My Answer: 1.946796568 (How about this one? Right or no?)

Problem 3

One of the oceans covering the surface of the earth is found to contain approximately 7.87E8 km3 of water. What is this volume in gallons?
Enter scientific notation as 1.23E4.

My Answer: 2.079e14 Gal (Still unsure...)

Problem 4

A cylindrical glass tube 15.1 cm in length is filled with ethanol. The mass of ethanol needed to fill the tube is found to be 9.75 g. Calculate the inner diameter of the tube in mm. (The density of ethanol is 0.789 g/mL)

===This one has me stumped. I am not sure where to began other then converting the given distance to meters first====

Problem 5
The radius of the silver atom is 144 pm. How many of these will span a distance of 44.9 cm?
Enter scientific notation as 1.23E4

===I am half way thru this one somewhat. But then again I am unsure if that part is even ri ght. I am trying to make a kinda T-chart where for example 2.54cm=1inch and make them cancel the others. Hard to explain what I am talking about but I am sure someone knows what I a mean.



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Problems 1 thru 3 I worked but unsure with my answer. Problems 4 thru 5 I need a little help on. I am not asking anyone to do my homework for me. I am just asking for a little guidance or examples. If I had a could coverting chart that had all the (1g=1000ml, 1inch=2.54cm, and so on) but I cant seem to find one Just for chemistry if there is such a thing. Yup and I have googled it but maybe I am just not looking or typing in the write words.
If you guys/ladies could assist me in anyway with a website just for chemistry converting stuff then I would be most greatful. This was pretty close if not it but don't wanna bug people with chem questions.

Thanks in advance to anyone who can be of assistance, if not. Thanks anyways :)

[patricia39]

Conversion is not too difficult to study but you really need to have a conversion table. I suggest, you check conversion tables online as reference for your homework. Try to search conversion.com or onlineconversion.com websites.

[daavidfischer]

For the question "A cylindrical glass tube 15.1 cm in length is filled with ethanol. The mass of ethanol needed to fill the tube is found to be 9.75 g. Calculate the inner diameter of the tube in mm." The right answer is 1.02 cm.(The volume of a cylinder is defined as: V = πr² h, From this we can find the radius. We're asked to find the diameter, which is twice the radius: )