25.0 cm3 of a 0.10 moldm-3 solution of sodium hydroxide was titrated against a solution of hydrochloric acid of unknown concentration. 27.3 cm3 of the acid was required. What was the concentration of the acid? 3. 25 cm3 of a solution of sodium hydroxide reacts with 15 cm3 of 0.1 mol/dm3 HCl.
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.
There will have some error. 2) A volatile liquid was allowed to evaporate in a 43.298 g flask that has a total volume of 252 ml. the temperature of the water bath was 100˚C at the atmospheric pressure of 776 torr. The mass of the flask and condensed vapor was 44.173 g. calculate the molar mass of the liquid. T = 273 + 100 = 373 V = 252 mL = 1 L / 1000 mL = 0.252 L P = 776 Torr R= 0.0821 mass of 44.173 - 43.298 g = 0.875g moles of gas = PV / RT = 776 x .252 / 62.363 x (273+100) =0.00841 moles molar mass = 0.875g / 0.00841 moles = 104.1 g/
Part C: Density of Sodium Chloride (NaCl) Solution, a sample of NaCl was obtained and measured using a 100mL beaker and a 10mL pipet to determine the concentration of the solution. In order to obtain the appropriate result, a calibration graph and density measurement was used to determine the concentration of the sodium chloride solution. In conclusion, based on the water temperature of 21.8°C in part A’s graduated cylinder experiment obtained, it was determined that the average density was .0973g/mL with a percentage error of 2.5%. When graphed the measurement was equal to Y=0.988x. Part B: The graduated pipet’s average density at 22.3 °C was determined to be 0.9785g/mL with a percentage error of 1.89% shows the graduated pipet to be more accurate and precise.
The change in enthalpy relies on the concentration of the salt solution, because different concentrations will produce different enthalpies. There is an equation to determine how much of this heat energy is lost or gained when a reaction is performed. Q = c m (T1-T2) Where: q is the energy in Joules C is the heat capacity, measured in joules per gram per degree Celsius M is the mass of the solution, measured in grams J is the joules G is the grams of water T is the temperature ΔH=ΔE + PΔV = (q p +w) – w = q p Procedure: 1. Follow instructions 1-9 in Appendix A-1 to initialize the MeasureNet workstation. a.
Let’s call this number X. Then the structural formula of BaCl2 hydrate can be written as BaCl2•XH2O. The reaction of dehydration is |BaCl2•XH2O ( BaCl2 + XH2O |(5) | According to the stoichiometry of the reaction (5) |[pic] |(6) | Where N1 is the number of moles of BaCl2 formed in the reaction (5) and N2 is the number of moles of water lost in the reaction (5). To find out N1 you need to divide the mass of BaCl2 after the reaction by its molar mass. To find out N2 you have to determine the mass of water produced in the reaction.
93 g/mol? Not we get to use it! Yay! 93 g/mol / 31.06 g/mol = 3 (this is the multiplier) Multiply that whole number through the subscripts of the empirical formula. 3 x (C H5 N) = C3H15N3 Hydrated compounds Solving process: 1st- the difference between the initial mass and that of the dry sample is the mass of water that was driven off.
Solution Stoichiometry and Gas Law Problems Problem 1 In flask A, 1.500g of silver nitrate solid is dissolved in 50.0mL of water, while in flask B, 0.500g of potassium carbonate is dissolved in 25.0mL of water. The two solutions are then mixed together. a) Before mixing, what is the molarity of each solution? b) Write the balanced molecular equation, the complete ionic equation, and the net ionic equation for the reaction. c) If the percentage yield is 85.0%, what mass of precipitate is actually produced?
Pre-Lab Questions 1. A determination of the molar mass of methyl alcohol (CH3OH) yielded the following data. Temperature of boiling water bath 99.5o C Barometric pressure 738 mm Hg Temperature of room temperature water 24.0o C Density of room temperature water 0.9973 g/mL Trial 1 Mass of empty pipette 1.557g Mass of piet and condensed methyl alcohol 1.571g Mass of pipet and water 16.001g Mass of condensed methyl alcohol 0.014g Mass of water in filled pipet 14.444g Volume of pipet 14.483mL Molar mass of methyl alcohol (experimental) 28.69 g/mol Molar mass of methyl alcohol (theoretical) 32.05 g/mol Using the data, fill in the rest of the table. The volume of the pipet is equal to the volume of water inside the pipet. Use the relationship of mass and density to determine this volume.
Measure 50.0 mL of 2.0 M Sodium Hydroxide, NaOH, solution but DO NOT ADD YET. Click the Collect button to get the initial temperature of the HCl solution. After the first four readings have been recorded at the same temperature, add the NaOH solution. Make sure you have lowered the paper lid to keep from liquid coming out of the cup. Turn the Stirrer on, at a slow to medium speed.