1 / 13

Sample Problems:

Sample Problems:. 1. How many grams are in 45 L of neon gas at STP?. 1 mol 22.4 L. 20.180 g 1 mol. 45 L. = 41 g. Sample Problems:. 2. How many formula units are in 36.4 g of NaCl ?. 6.02 x 10 23 form.units 1 mol. 1 mol 58.443 g. 36.4 g. = 3.75 x 10 23 formula units .

sef
Télécharger la présentation

Sample Problems:

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Sample Problems: • 1. How many grams are in 45 L of neon gas at STP? 1 mol 22.4 L 20.180 g 1 mol 45 L = 41 g

  2. Sample Problems: • 2. How many formula units are in 36.4 g of NaCl? 6.02 x 1023form.units 1 mol 1 mol 58.443 g 36.4 g = 3.75 x 1023 formula units

  3. Sample Problems: • 3. What is the mass of 550 L of helium gas at STP? 1 mol 22.4 L 4.003 g 1 mol 550 L = 98 g

  4. Sample Problems: • 4. How many liters are in 5.6 x 1024 atoms of helium gas at STP? 5.61024 atoms 1 mol 6.021023atoms 22.4 L 1 mol = 210 L

  5. Find % sodium in Na2O. Molar mass = Na 22.990 x 2 = 45.98 O 15.999 x 1 = 15.999+ 61.979 g % Na = Part Whole 45.98 g 61.979 g = X 100 = 74.19 %

  6. Find the % composition of a compound that has 5.34g C, 0.42g H, & 47.08g Cl. Mass (total)= 5.34g + 0.42g + 47.08g = 52.84g %C = 5.34g C x 100% = C 52.84g %H = 0.42g H x 100% = H 52.84g %Cl = 47.08g Cl x 100% = Cl 52.84g 10.11 % 0.79 % 89.10 %

  7. How many grams of sodium are in 650.0 g of Na2CO3? Na: X ___= _________ C: X ___= __________ O: X ___ = __________ TOTAL: (Whole) 45.98 22.990 2 12.011 12.011 1 15.999 47.997 3 105.988

  8. Formula: part x grams(total) = Answer whole grams Na = x 650.0 g 45.98 105.988 = 282.0 g Na

  9. 4) Calculate the percent composition of C3H7OH (2-propanol).

  10. Percent composition Homework page 15

More Related