What is the mass of 3.8 × 1024 atoms of argon (Ar)? 0.0039 g 0.16 g 6.3 g 250 g?
-0.0039 g
-0.16 g
-6.3 g
-250 g
I think it's 6.3 but i'm not sure..
thank you :)
Update:How many moles of chlorine (Cl) atoms are in a sample of 1.72 × 1022 atoms?
0.0286 mol Cl
35.0 mol Cl
1.03 × 1023 mol Cl
1.04 × 1046 mol Cl
I also am having problems with this one..
More Questions From This User See All
Answers & Comments
Verified answer
Hello, Christina. Let's see if I can help you a bit with your questions.
#1). You are given a number of Argon atoms, 3.8x10^24 actually, and are told to determine their mass, in grams, but there isn't a balance. What to do?
You know a mole contains 6.022x10^23 atoms.
You know, from your Periodic Table, Ar has a mass of 39.948 g/mol.
You know you were given more than 1mol Ar, as, 3.8x10^24 > 6.022x10^23.
To solve this question divide 3.8x10^24 by 6.022x10^23 = 6.31 mols Ar are present. Multiply this 6.31 by 39.948 = 252.07188 grams Ar are in the sample. As the least precise, and only, measurement given contains 2 sigfigs the answer can only contain 2 digits. The correct answer is 250 grams.
#2). You can solve this in the same manner. As 1.72x10^22 atoms are less than the 6.022x10^23 required to constitute a mole the answer will be less than a mole. Divide 1.72x10^22 by 6.022x10^23 = 0.02856, in sigfigs 0.0286 mol Cl.
That wasn't so very difficult, Christina, now was it.
The beginning of the term "G-string" is obscure. The term is first attested in writings via individuals interior the late 1800s describing the loincloth of Philippines natives. interior the "Philippines Islands" get entry to interior the 1911 version of the Encyclopædia Britannica, the term "geestring" is used. Others say the term is derived from the G-string on a musical device, whether it would desire to be an abbreviation of "groin-string". The beginning of the be conscious "thong" is from the previous English thwong,a versatile leather-based twine. there are assorted intermediate varieties between finished rear insurance and a string rear. like the tanga, the g-sting is basically a backside masking that covers the pubis and leaves the buttocks bared; The term g-string is in lots of cases used whilst the vertical strap interior the rear of a thong isn't any wider than a string. different comparable varieties comprise the brazilian, rio, and t-back. The naming of the intermediate cuts is arguable, and distinctive distributors use the words fairly interchangeably. Wikipedia
divide 3.8 * 10^24 atoms by 6.022x10^23 (avogadro's number) to get moles and then multiply by the MM of Argon to get grams...
Part B
Divide 1.72 * 10^22 atoms by avogadro's number to get moles.