A sample of 2.05 g of polystyrene of uniform polymer chain length was dissolved in enough toluene to form 0.100 L of solution. The osmotic pressure of this solution was found to be 1.21 kPa at 25°C. Calculate the molar mass of the 8- polystyrene. a) 2.35 x 10 g/mol b) 4.20x 105 g/mol C) 3.05 x 105 g/mol 205196. 4.20x 103 g/mol e) 4.20 x 10 g/mol Boş bırak

Cadmium bromide is used in photography and lithography. Calculate the molality of a solution prepared by dissolving 45.38 g of CdBr2 in 375.0 g of water. Multiple Choice 0.4446 m 0.03035 m 0.1210 m 0.01600 m

2. What mass of toluene (C6H5CH3) was added to 233.6 g of benzene (C6H6) if the vapor pressure of benzene became 61.8 mmHg.  The vapor pressure of pure benzene is 70.1 mmHg at 18 oC.  Answer to 1 decimal place.

Why can't water alone clean soiled clothes effectively? How does the detergent help in the cleaning or washing of clothes? How do surfactants affect the surface tension of tap water? What will be the effect of increasing its amount on a fixed volume of water?

12. The boiling point of an alcohol is 77.870 ᵒC. at 1atm. When 13.64 g of an unknown compound was dissolved in 235.1 g of this alcohol, the solution boiled at 79.228 ᵒC. Kb of this alcohol is 1.160 ᵒC/m. What is the molar mass of the unknown compound?

1.55 g potassium nitrate is added to a calorimeter containing 100.0 mL. water at 22.50 oC.  The temperature is changed to 18.00 oC.   Calculate the heat of dissolution in kJ / mole of potassium nitrate. K = 39.10 g/mole,  N = 14.00 g/mol,  O = 16.00 g/mole. Hint: This is a diluted solution:   D= 1.00 g/mL.,   CP = 4.184 J/ g oC.  heat capacity of calorimeter  is 51.7 J / oC.   N = 14.00 g/mole,  K = 39.10 g/mole,    O = 16.00 g/mole   a. 140. kJ/moleb. -140. kJ/molec. 24.3 kJ/ moled.-176 kJ/mole

In what context do the terms hydrophobic and hydrophilic relate to the solubilities of substances in water?

The atomic radii of a divalent cation and a monovalent anion are 0.15 nm and 0.143 nm, respectively. (a) Calculate the force of attraction between these two ions at their equilibrium interionic separation (i.e., when the ions just touch one another). i ! N (b) What is the force of repulsion at this same separation distance? N i

At room temperature, toluene has a vapor pressure of 300mmHg and ethanol has a vapor pressure of 45mmHg. Let us assume that when equimolar amounts of these liquids are mixed together, heat is released. What can be said about the vapor pressure of the resulting solution? O The vapor pressure will be 172.5 mmHg because there are equal amounts of both liquids. O The vapor pressure is less than 172.5 mmHg because the reaction is exothermic. O The vapor pressure will be 300 mmHg because toluene has the greater vapor pressure, which cancels out the vapor pressure of ethanol. O The vapor pressure will be 345 mmHg because the vapor pressure values are additive.

Which of the following compounds can form hydrogen bond with water: ethanol, 1-decanol, glycerin, sucrose and urea? State a reason why each compound will or will not form hydrogen bond with water. What effect will hydrogen bonding have on the solubility of each compound in water? In hexane?