Calculating how to make a 1:1 mixture of two reagents with different molecular weights

1. Calculating how to make a 1:1 mixture of two reagents with different molecular weights Identify components Calculate molecular weight Calculate 1:1 mixture

2. Identify the components H2O + NaCl H Na O Cl NaHCO3 + HC2H3O2 Na H H C C O The first step is to look at the reagents and identify the components of the reagents. The first step is to look at the reagents and identify the components of the reagents.

3. The Periodic Table Find the molecular weight for each componentFind the molecular weight for each component

4. MSDS sheetMaterial safety Data sheet Synonyms: Sodium hydrogen carbonate; sodium acid carbonate; baking soda; bicarbonate of soda CAS No.: 144-55-8 Molecular Weight: 84.01 Chemical Formula: NaHCO3 Product Codes: General Synonyms: bicarbonate of soda, baking soda, sodium hydrogen carbonate, bicarb, sodium acid carbonate, Col-evac, jusonin, NEUT, soda mint Molecular formula: NaHCO3 CAS No: 144-55-8 EINECS No: 205-633-8 Physical data Appearance: white powder or crystals Melting point: 50 C Boiling point: Vapour density: Vapour pressure: Density (g cm-3): 2.16 Flash point: Explosion limits: Autoignition temperature: Water solubility: � Stability Stable. Toxicology Not hazardous according to Directive 67/548/EEC. Toxicity data (The meaning of any abbreviations which appear in this section is given here.) ORL-RAT LD50 4220 mg kg-1 ORL-MUS LD50 3360 mg kg-1 Transport information Non-hazardous for road, air and sea freight. Personal protection None necessary. [Return to Physical & Theoretical Chemistry Lab. Safety home page.] MDSD sheets contain the molecular weight and other valuable safety informationMDSD sheets contain the molecular weight and other valuable safety information

5. Determine the molecular weightof each compound H2O + NaCl ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ H=1(2)=2 Na=23(1)=23 O=16(1)=16 Cl=35.5(1)=35.5 _____ _______ H2O=18 NaCl=58.5 Break down each component and calculate the weight. Do not forget to multiply by the number of molecules of each.Break down each component and calculate the weight. Do not forget to multiply by the number of molecules of each.

6. Now calculate for a 1:1 solution H2O + NaCl +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ H2O=18 NaCl=58.5 18(H2O) + 58.5(NaCl) = X(18) + 58.5 = 1:1 58.5/18 = 3.25 3.25(18) H2O+ 1(58.3)NaCl= 1:1 mixture Notice that NaCL is approximately 4 times heavier than H2O. Divide 58.3 by 14 to determine how much more water to use to make a 1:1 mixtureNotice that NaCL is approximately 4 times heavier than H2O. Divide 58.3 by 14 to determine how much more water to use to make a 1:1 mixture

7. Determine the molecular weightof each compound NaHCO3 + HC2H3O2 ___________________________________ Na=23(1)=23 H=1(4)=4 H=1(1)=1 C=12(2)=24 C=12(1)=12 O =16(2)=32 O =16(3)=32 ______ _______ NaHCO3 = 84 HC2H3O2 = 60 This is baking soda and vinegar.This is baking soda and vinegar.

8. NaHCO3 + HC2H3O2 __________________________________________________________________________________________________________ NaHCO3 =84 HC2H3O2 = 60 84(NaHCO3) + 60(HC2H3O2)= 84 + X(60)=1:1 84/60=1.4 1(84) NaHCO3 + 1.4(60) HC2H3O2 = 1:1 mixture Now calculate for a 1:1 solution In this instance NaHCO3(baking soda) is the larger compound. More HC2H3O2 (vinegar) is needed to make a 1:1 solution. In this instance NaHCO3(baking soda) is the larger compound. More HC2H3O2 (vinegar) is needed to make a 1:1 solution.

9. Why 1:1 solutions? The ability to calculate the molecular weight of a compound and create a 1:1 solution is useful in many scientific applications. Even the most basic baking soda and vinegar volcano. The calculation determines how much of each is needed for a complete reaction.