1 / 14

CA Standards

Understand the concept of stoichiometry and learn how to calculate masses of reactants and products in chemical reactions. This guide covers balanced equations, molar conversions, and mole ratios. Practice problems provide step-by-step solutions.

dcharlotte
Download Presentation

CA Standards

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. CA Standards Std. 3e: Students know how to calculate the masses of reactants and products in a chemical reaction from the mass of one of the reactants or products and the relevant atomic masses.

  2. What is Stoichiometry? The study of quantities of materials consumed and produced in chemical reactions.

  3. How Are Stoich Problems Different? • Includes a balanced equation and molar conversions. • Coefficient of equation shows molar relationship (Mole ratio) of reactants and products. Ex: 2H2 + O2 2H2O 2 mol H2 + 1 mol O2 2 mol H2O Ex: Mole Ratio of H2: H2O  2 mol H2 2 mol H2O

  4. Calculating Masses of Reactants and Products • Check if equation is balanced. • Convert mass(g) or volume(L) to moles, if necessary. • Set up mole ratios. • Use mole ratios to calculate moles of desired substituent. • Convert moles to mass or volume, if necessary.

  5. Stoich problem Type #1 Ex 1: How many moles of NH3 can be produced when 4 moles of N2 is reacted with excess H2? N2 + 3H2 2NH3 4 mol N2 2 mol NH3 1 mol N2 = 8 mol NH3

  6. Ex 2: 2N2 + O2 2N2O How many moles of N2 must be reacted with excess O2 to produce 10 moles of N2O? 10 mol N2O 2 mol N2 2 mol N2O = 10 mol N2

  7. Grams of Given to Grams of Unkown Roadmap MEMORIZE!!! (Mole Ratio) g GIVEN  mol GIVEN  mol UnKnown  g UNKNOWN mol GIVEN

  8. Stoich Problem Type#2 Ex 3: 46 grams of Sodium (Na) reacts with an excess Chlorine (Cl). How many grams of Sodium Chloride (NaCl) are formed? 2Na+Cl22NaCl 46 g Na 1 mol Na 2 mol NaCl 58 g NaCl = 2 mol Na 1 mol NaCl 23 g Na 116 g NaCl

  9. Ex 4: How many grams of water can be prepared from 8 grams of hydrogen at standard conditions? 2 H2 (g) + O2(g) → 2 H2O 8 g H2 2 mol H2O 18 g H2O 1 mol H2 2 g H2 1 mol H2O 2 mol H2 = 72 g H2O

  10. Gas Stoichiometry If reactants and products are at the same conditions of temperature and pressure, then mole ratios of gases are also volume ratios. 3H2(g) + N2(g)  2NH3(g) 3moles H2 +1mole N2  2moles NH3 3liters H2 + 1 liter N2 2liters NH3

  11. Gas Stoichiometry Ex 5: How many liters of NH3 can be produced when 12 liters of H2 react with an excess of nitrogen? 3 H2(g) + N2(g)  2NH3(g) 12 L H2 2 L NH3 = L NH3 8.0 3 L H2

  12. Ex 6: How many liters of oxygen are required to react completely with 22.4 liters of carbon monoxide, CO, at standard conditions? 2 CO (g) + O2(g) → 2 CO2 (g) 22.4 L CO 1 L O2 = L O2 11.2 2 L CO

  13. END OF UNIT 3: Woo Hoo!

  14. Everyday STOICH S’mores: G2 + C + M  G2CM + +  How many S’mores can I make with 5 Graham crackers, 3 marshmallows and 1 Chocolate?

More Related