1 / 7

Rice Lab

Rice Lab. Count out 1 dozen grains of rice and place in container. Repeat until you have 3 containers each holding 12 grains of rice. Mass each dozen and calculate the average mass of 1 dozen grains of rice. (Don’t forget to minus out the mass of container.)

adonia
Download Presentation

Rice Lab

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. Rice Lab • Count out 1 dozen grains of rice and place in container. • Repeat until you have 3 containers each holding 12 grains of rice. • Mass each dozen and calculate the average mass of 1 dozen grains of rice. (Don’t forget to minus out the mass of container.) • Calculate the number of rice grains in 1.94 gram of rice. • Mass out rice grains until you reach a mass equal to the mass you calculated above. • Count the grains of rice in the sample. • Calculate the percent error between the calculated number of rice grains versus the actual number of rice grains. Episode 701

  2. Mole • Avogadro’s number • the mole = 6.022 x 1023 • 602,200,000,000,000,000,000,000 • Molar Mass • Themass of one mole of any pure substance Episode 701

  3. Molar mass of an element (g/mol) • Equals the atomic mass of the element in grams • Molar mass of a compound • Equals the sum of the molar masses of the elements making up the compound • Find the molar masses of- • Magnesium g/mol • Chlorine g/mol • Magnesium chloride • Write formula • Find the atomic mass of each element • Multiply atomic mass by the number of atoms for each element, then total the masses • MgCl2 • 24.3 g/mol + (2 x 35.5 g/mol) = 24.3 35.5 95.3 g/mol Episode 701

  4. Try it! • Find the molar mass of aluminum oxide • (2x 27 g/mol) + (3 x16g/mol) • 102 g/mol Episode 701

  5. Remember Rice Lab Calculations… • How many moles of atoms are there in 8.0 grams of Mg? ? moles = 8.0g Mg • How many atoms are in 0.7 grams of He? ? atoms = 0.7g He 1 mol Mg 24.3 g/mol 1 mol He 6.022 x 1023 atoms 4.0 g/mol 1 mol He Episode 701

  6. Formula Units… No Problem • What would the mass of 5.3 x 1022 formula units of calcium iodide? Formula Molar Mass ?g CaI2 = 5.3 x1022 fu CaI2 40.1 g/mol + (2 x 126.9 g/mol) = 293.9 g/mol 1 mol CaI2 293.9 g CaI2 6.022 x 1023 fu 1 mol CaI2 26 g CaI2 Episode 701

  7. Problem Set 1 • How many atoms are in 3.5 grams of silicon? • How many formula units are in 32.6 grams of potassium oxide? • How many molecules are in 0.25 grams of dinitrogenpentoxide? ? atoms = 3.5g Si 1mol Si 6.022 x 1023 atoms = 7.5 x 1023 atoms Si 28.1g Si 1 mol Si ? fu = 32.6 g K20 1mol K2O 6.022 x 1023 fu = 2.1 x 1023 fu K2O 94.2g K2O 1 mol K2O ? molec = 0.25 g N2O5 1mol N2O5 6.022 x 1023 molec = 1.4 x 1021 mole N2O5 108 g N2O5 1 mol N2O5 Episode 701

More Related