This solution was placed in a burette and 18.4 cm3 was required to neutralise 25 cm3 of 0.1 moldm-3 NaOH. Deduce the molecular formula of the acid and hence the value of n. 5. Sodium carbonate exists in hydrated form, Na2CO3.xH2O, in the solid state. 3.5 g of a sodium carbonate sample was dissolved in water and the volume made up to 250 cm3. 25.0 cm3 of this solution was titrated against 0.1 moldm-3 HCl and 24.5 cm3 of the acid were required.
Eighth, and last, I found molecular weight of sugar and diluted it. Data Tables and Observations: Data Table 1: Length measurements. | Object | Length (cm) | Length (mm) | Length (m) | CD or DVD | 5.2 | 52.0 | .052 | Key | 12.0 | 120.0 | .120 | Spoon | 18.6 | 186.0 | .186 | Fork | 21.0 | 210.0 | .210 | Data Table 2: Temperature measurements. | Water | Temperature (°C) | Temperature (°F) | Temperature (K) | Hot from tap | 46 | 114.8 | 319.15 | Boiling | 100 | 212 | 373.15 | Boiling for 5 minutes | 100 | 212 | 373.15 | Cold from tap | 18 | 64.4 | 291.15 | Ice water – 1 minute | 0 | 32 | 273.15 | Ice water – 5 minutes | 0 | 32 | 273.15 | Data Table 3: Mass measurements. | Object | Estimated Mass (g) | Actual Mass (g) | Actual Mass (kg) | Pen or pencil | 5 | 5.4 | .0054 | 3 Pennies | 6 | 7.6 | .0076 | 1 Quarter | 5 | 5.7 | .0057 | 2 Quarters, 3 Dimes | 15 | 18.2 | .0182 | 4 Dimes, 5 Pennies | 15 | 21.6 | .0216 | 3 Quarters, 1 Dime, 5 Pennies | 25 | 31.9 | .0319 | Key | 10 | 9.2 | .0092 | Key, 1 Quarter, 4 Pennies | 20 | 24.9 | .0249 | Data Table 4: Liquid measurements.
|Mass of insulated test tube, spin bar, cyclohexane and |353.25g | | |unknown | | |4. |Mass of unknown |0.15g | A. Warming Curve Data-Pure Cyclohexane |Time |Temp °C |Time |Temp °C |Time |Temp °C |Time |Temp °C | |2.56.30 |6.9 |2.59.30 |6.8 |3.02.30 |6.8 |3.05.30 |7.9 | |2.57.00 |6.9 |3.00.00 |6.9 |3.03.00 |6.9 |3.06.00 |8.2 | |2.57.30 |6.9 |3.00.30 |6.9 |3.03.30 |6.9 |3.06.30 |8.5 | |2.58.00 |6.8 |3.01.00 |6.8 |3.04.00 |7 |3.07.00 |8.9 | |2.58.30 |6.8 |3.01.30 |6.8 |3.04.30 |7.1 |3.07.30 |9.2 | |2.59.00 |6.9 |3.02.00 |6.8 |3.05.00 |7.6 |3.08.00 |9.5 | [pic] 5. Freezing point of pure cyclohexane, from warming Curve is 6.0°C B. Warming Curve Data-Solution Containing Unknown – 941 Trial 1 |Time
Warm Up Questions: 1. Exercise 1: a. 2.56 ZnI2=x moles of ZnI2 b. 500 ml=0.500L c. The flask would be labeled as 0.0161 ZnI2/L Solution 2. Exercise 2: a.
EXPERIMENT 11 Molar Mass of a Volatile Liquid DATA Run | UNKNOW | Mass of flask and foil(g) | 90.085g | Mass of flask and foil and condensed vapor (g) | 90.640g | Temperature of boiling water (˚C ) | 98˚C | Barometric pressure (torr) | 761mm Hg | Volume of flask (mL) | 140 mL | RESULTS Mass of unknown ( condensed vapor) | 0.555g | Volume of flask (vapor)(L) | 0.14 L | Temperature of vapor(k) | 371K | Molar mass of unknown (g/mole) | 118.380 g/mole | Advance Study Assignment 1) How would each of the following errors affect the outcome of this experiment? Would it make the molar mass high or low? Give your reasoning in three sentences or less in each case. a) The hole in the aluminum foil was quite large. if you were to have a larger hole in your aluminum cap, you would be losing vapor to the room.
The following data were obtained when a sample of barium chloride hydrate was analyzed as described in the Procedure section. Calculate (a) the mass of the hydrate, (b) the mass of water lost during heating, and (c) the percent water in the hydrate. Mass of empty test tube 18.42 g Mass of test tube and hydrate (before heating) 20.75 g Mass of test tube and anhydrous salt (after heating) 20.41 g. Mass of the Hydrate is 2.33g. Loss (H2O) is 0.34g. Percent H2O in Hydrate is equal 0.34/2.33=14.6% 3.
Pb (NO3) 2 10. A compound is 42.3 % C, 5.94 % H, 32.9 % N, and 18.8 % O and has a molecular mass of 425.25 g/mol. Calculate the empirical and molecular formula. C15H25N10O5 11. How many moles of Al2O3 are produced by the reaction 200. g Al?
Empirical formula: CH5N Steps for molecular formula: 1- Calculate the molar mass of the empirical formula. 2- Divide the known (given) molar mass by the calculated empirical formula molar mass to get a whole number 3- Multiply that whole number through subscripts of the empirical formula to obtain the molecular formula. Example CH5N 12.01 g C x 1 C= 12.01 g/mol 1.008 g H x 5 H = 5.040
0.00512g ZnI2/mL of solution 0.00512g/319.18 g/mol=1.6*10-5 mol 1.6*10-5 mol/(1*10-3L)=0.016M c. 0.00806 moles of ZnI2/500 mL of solution 0.00806mol/(500*10-3)L=0.016M d. 0.0161 moles of ZnI2/L of solution 0.0161mol/1L=0.016M Exercise 4: a. The moles of ZnI2: 0.25M*(250*10-3)L=0.0625mol b. 0.25M*(250*10-3)L=0.0625mol The mass of ZnI2: 0.0625mol*319.18 g/mol=19.95g c. 0.25M*(500*10-3)L=0.125mol 0.125mol*319.18 g/mol=39.9g ZnI2 d. 0.0125mol/0.25M=0.05L Exercise 5: a. 0.125M*(100*10-3)L=0.0125mol b. 0.0625mol/0.125M=0.5L=500mL Calculation for preparing the EDTA solution Exercise 6 a.
Laboratory Techniques and Measurements Purpose: Learn about the various types of measurements such as gram, milliliter, centimeter, cm^3, Celcius, and Kelvin and how they translate into other forms of measurement. Procedure: Take various measurements Data Tables: |Data Table 1: Length measurements. | |Object |Length (cm) |Length (mm) |Length (m) | |CD or DVD |12 |120 |.12 | |Key |5.2 |52 |.052 | |Spoon |17.3 |173 |.173 | |Fork |17.7 |177 |.177 | |Data Table 2: Temperature measurements. | |Water |Temperature (°C) |Temperature (°F) |Temperature (K) | |Hot from tap |41 |105.8 |314.15 | |Boiling |97 |206.6 |370.15 | |Boiling for 5 minutes |100 |212 |373.15 | |Cold from tap |25