Procedure: Mix the two solutions together. Stir by stir bar and stir plate, swirl the mixture in the flask by hand, or mix by transferring the mixture back and forth between the two flasks. Stir until the colorless solution turns blue (about 10 seconds). Clean-Up: Remaining blue solution can be washed down drain with water . Background: For the entire explanation of this demo see Shakhashiri's Chemical Demonstrations, Vol.
Mixed Solutions: If 1 mmole of glucose (180mg=1mOsm) and 1 mmole of NaCl (58mg=2mmOsm) are put into a beaker and distilled water added to make 1 liter, the osmolarity is 3 mOSm/L. OSMOSIS CALCULATIONS: 1. Calculate the number of grams of NaCl needed to prepare 100 mL of a 280mOsm.L Solution. (280mosm/l) *(1L/1000mL)*(100mm/1)*(29mg/1mosm)*(1g/1000mg)=0.812g 2. Calculate the number of grams of glucose needed to prepare 100mL of a 280 msm/L glucose solution.
Using a measuring cylinder, add 50cm3 of 1.0mol dm-3 sulphuric(VI) acid to the thyme extract in the conical flask. 8. Titrate the solution in the conical flask with the potassium manganate(VII) solution until a pale pink colour persists for 10 seconds. 9. Repeat the titration until there are two titres within 0.1cm3 of each other.
This occurs at the point when the log ([HPO₄²⁻] / [H₂PO₄⁻] = 0. Using the interpolation calculator the value of pKa = 6.87. Now to determine the pKa of the dye Blue (1). This was done by constructing a plot of absorbance vs. pH of the buffers. This “S” curve plot can be seen below in Figure 2.
The carbonate anion test mixes 1 mL of test solution and drops of 6M HCl. The formation of bubbles shows the presence of carbonate (CO32-). The acetate anion test heats 2 mL of the test solution, 1 drop of 18M H2SO4, and 1 mL (100%) ethanol. A fruity smell, using the wafting technique, shows the presence of acetate
Procedure 1. Begin to prepare an EDTA solution. Weigh out 3.62-3.64 g of NaH2EDTA and record exact mass. Add the weighed amount to a 250 ml volumetric funnel carefully using a funnel Wash the funnel with water to ensure all of the solid is delivered to the flask Add 100-200 ml of water and mix. Enough water should be added so that the flask is full to the 250 ml mark Tightly wrap the top of the flask with a Parafilm when finished 2.
Materials: • 2 Graduated Cylinders • Distilled Water • Stirring Rod • Balance • One 250ml Beaker • One Erlenmeyer Flask • Filter Paper • Copper (II) Sulphate Pentahydrate • Strontium Chloride Hexahydrate Procedure 1. Two graduated cylinders are used and 75ml of distilled water are added to both 2. The two reactants are made into a solution by
Part II - Spectral Analysis 1)Ensure that the instrument has had time to warm up for 15 min. 2)Set the wavelength to 450 nm. Set the percent transmittance to zero. 3)With distilled water in the cuvet, place the cuvet into the spectrophotometer. Adjust the percent transmittance to 100% 4)our out the water in the cuvet, and fill with 2/3 of the reference solution.
Fill both jars each with 70 drops of bromthymol bblue 8. Get a different dropper and suck up seltzer water with it 9. Add in 20 drops of seltzer water in only one jar 10. Securely close both jars with their cap 11. Put the jar that has the seltzer water in it in the sunlight 12.
Calculate the exact normality of Na2S2O3 knowing that in this chemical reaction 1 gram-equivalent of K2Cr2O7 react with 1 gram-equivalent of Na2S2O3 (1 mole K2Cr2O7 react with 6 moles Na2S2O3). Determination of peroxide value. Weigh 3.00 g oil (with precision of 0.001 g) into a 250 ml Erlenmeyer flask. Add 10 ml chloroform and swirl to dissolve oil. Add 15 ml acetic acid,