1. Calculate the change in entropy when 50 kJ of energy is transferred reversibly and isothermally as heat to a large block of copper at (a) 0°C, (b) 70°C. 2. Calculate ΔS (for the system) when the state of 2.00 mol diatomic perfect gas molecules, for which Cp,m = 7/2 R, is changed from 25°C and 1.50 atm to 135°C ... Read more

1. A chemical reaction takes place in a container of cross-sectional area 50.0 cm2. As a result of the reaction, a piston is pushed out through 15 cm against an external pressure of 121 kPa. Calculate the work done by the system. 2. A sample consisting of 2.00 mol He is expanded isothermally at 22°C from 22.8 dm3 to 31. ... Read more

1. Could 25 g of argon gas in a vessel of volume 1.5 dm3 exert a pressure of 2.0 bar at 30°C if it behaved as a perfect gas? If not, what pressure would it exert? (b) What pressure would it exert if it behaved as a van der Waals gas? (a= 1.354 dm6 bar mol-2 and b= 3.20 x ... Read more

QUESTION I: CALCULATE SOLUBILITY (CONCENTRATION) OF AGCL IF THE SPECIFIC CONDUCTANCE AND MOLAR CONDUCTIVITY OF SILVER CHLORIDE SALT ARE 1.41×10-4 S CM-1 AND 138.26 S.CM2.MOL-1, RESPECTIVELY.CALCULATE SOLUBILITY (CONCENTRATION) OF AGCL IF THE SPECIFIC CONDUCTANCE AND MOLAR CONDUCTIVITY OF SILVER CHLORIDE SALT ARE 1.41×10-4 S CM-1 AND 138.26 S.CM2.MOL-1, RESPECTIVELY.CALCULATE SOLUBILITY (CONCENTRATION) OF AGCL IF THE SPECIFIC CONDUCTANCE AND MOLAR CONDUCTIVITY ... Read more

1. WHICH OF THE FOLLOWING PAIRS OF MOLECULES AND THEIR MOLECULAR GEOMETRIES IS WRONG? a. NF3 - trigonal planar b. H2O – bent c. BF3 - trigonal planar d. AsF5 - trigonal bipyramidal 2- WHICH OF THE FOLLOWING STATEMENTS IS TRUE? a. The total number of molecular orbitals formed doesn’t always equal the number of atomic b. A bond order ... Read more

1-Why diamond is stronger than graphite? 2- What is the hybridization in graphite? 3- Mention the boron compounds. Read more

—What are the symmetry elements and the point group of the following: —CHCl3 —AlF3 —CCl4 —H2S —PH3 Read more

1- The wavelength of a laser pointer is reported to be 500nm. What is the frequency of this light? 2- If ml has values of (0) and (-1, 0, +1). write the corresponding value of n and l. 3- Which atomic orbitals has values of n = 4 and l = 2? 4- Calculate the wavelength (in nm) of a ... Read more

1-In an ELECTROLYTIC cell the electrode at which the electrons enter the solution is called the ______ ; the chemical change that occurs at this electrode is called _______. (a) anode, oxidation (b) anode, reduction (c) cathode, oxidation (d) cathode, reduction (e) cannot tell unless we know the species being oxidized and reduced. 2. Which of the following statements is ... Read more

Write a report about determination of molecular whieght of nonvolatile material. Read more