What is w when 1.83 kg of H20(1), initially at 25.0 °C, is converted into water vapour at 185 °C against a constant external pressure of 1.00 atm? Assume that the vapour behaves ideally and that the density of liquid water is 1.00 g/ml (Remember to include a+or-sign as appropriate.) Enter your answer in acceptable SI units, accurate to 3. significant figures. Use an acceptable Sl symbol for units.

When 0.6403 of g calcium bromide is dissolved in 75.00 mL water, the solution temperature increses by 1.07 °C. Calculate the enthalpy of dissolution (ΔHrxn) for calcium bromide, in kj/mol.(Assume constant pressure is, 41.84j/g. °C as the specific heat capacity of the solution, and a density of 1.00 g/ml). Write out the equation.  I am confused on where to start with this problem.

When 3.92 grams of an unknown non-volatile, non-electrolytic solute is added to 17.2 g of a particular solvent, the boiling point of the solvent increases by 2.80". Given that the molal boiling point constant is kb = 1.90 "/m_ What is the molar mass of the unknown solute (g/mol)? Equation: ikŕm 4T ΔΤ =

A student determined the molar mass of an unknown ionic solid by the method used in this experiment.  She found the equilibrium temperature of the ice water mixture (THE FREEZING POINT) to be 0.50°C on her thermometer.  When she added 3.10 g of her solid to the mixture, the temperature fell to -4.30°C. She then poured off the solution into a beaker.  The mass of the solution was 34.59 g.  Kf = 1.86°C/m What was the freezing point depression ∆Tf (celsius) What was the molality of the unknown solution? How much water was in the solution? What did she find to be the observed molar mass of the ionic solid, assuming she made the calculation properly?

The graph given below plots the (approximate) partial molar volumes of ethanol (black line) and water (red line) in units of ml/mole at 25°C in a mixture as a function of the mole fraction of ethanol. Use the information in this graph (note the different y axes for water and ethanol) and the densities at 25°C to calculate the resulting total volume of the g following two mixtures.(pethanol = 0.789 ml & PH20 = 0.998 ) ml a. 150 ml ethanol + 100 ml H2O b. 200 ml ethanol + 40 ml H2O H20 VELOH Vet o*HA -V ELOH V H2O T 0.8 1.0 0.2 0.4 0.6 0.0 XELOH 53 54 55 57 15 18

The freezing point of CCl4 was lowered by 0.52 K when 50 grams of a chemical were added to the solvent. Calculate the compound's molar mass. Kf of tetrachloromethane are equal to 30 kilograms per mole.

If 1000 L of gasoline has spilled into the street (MW=117 g/mol, density=0.7 g/mL which is true for octane) then firefighters add a lot of a material that dissolves into it that reduces the vapor pressure (liquid octane doesn’t burn, only the vapors). The firefighters put 500 kg of a material into the gasoline and reduced its vapor pressure from the pure partial pressure of 10.0 kPa down to 8.0 kPa. What is the molecular weight of the material that was added? (hint: use Raoult’s Law, which relates changes in pressure to the mol fractions.

Two 1-L beakers, A and B, each containing a different aqueous solution of fructose (a nonvolatile sugar with MW = 180.16 g/mol) are placed together in a box, which is then sealed. The temperature remains constant at 20 °C. Initially, there is 220 mL of solution in A and 650 mL of solution in B. As the solutions stand in the sealed box, their volumes change slowly for a while. When they stop changing, beaker A contains 430 mL and beaker B contains 440 mL. It is then determined that the solution in A is 1.74 M in fructose and has a density of 1.12 g mL-¹. (a) What is the molar concentration of fructose in the solution in beaker B at the end? M (b) Calculate the concentration of fructose in the solution in A at the start. M (c) Calculate the concentration of the fructose in the solution in B at the start. M (d) The vapor pressure of pure water at 20 °C is 17.5 torr. What is the pressure of water vapor in the box at the end, after the volumes have stopped changing? torr