Physical Chemistry Answers

What is the voltage for a cell constructed of Ni(s) in 1 x 10^-7 M Ni^2+ and Ag(s) in 1 x 10^-5 M Ag^+ ?
(Involves Nernst equation). I managed to get the answer= -0.95V. However the actual answer is 0.95V.
Do you know where I made a mistake?

Calculate the standard heat of formation of PCl5 (g), given that delta H = -136.0 kJ for the reaction: PCl5 (g) + H2O (g) yields POCl3 (g) + 2HCl (g)

reaction: 2KMnO4+H2O-->MnO2+2KOH+3(O).in the above reaction, if the molecular mass of KMno4 is 158 g mol-1,what will be the equivalent weight of KMnO4?

The energy (in joules) of an electron energy level in the Bohr atom is given by the expression: En = -2.179 x 10-18/n2 J where n is the principal quantum number for the energy level. What is the frequency in Hz of the electromagnetic radiation absorbed when an electron is raised up from level with n = 1 to that with n = 6?

Without sodium silicate solution (SSS), no geopolymer concrete can be produced.

Sodium silicate solution is defined commercially by its Na2O and SiO2 contents (thereby molar ratio or weight ratio). Density of liquid is helpful to compute its contents.
For example,
How to estimate pH of SSS, say SSS with Na2O=12%/, SiO2=25% and density of 1.49 kg/l ?

Na2O=1.49*12/100=0.1788 kg=1788/62 moles=2.884 moles,

SiO2=1.49*25/100=0.3725 kg=3725/60 moles=6.208 moles

I wanted to know how to use equilibrium conditions/constants to compute pH

Dr N P Rajamane
SRMU, India (Ex-CSIR-SERC)
rajamanenp@yahoo.co.uk

Whats a chemical that will change a color when coming in contact with Lactic Acid ?

4.5 moles of an ideal gas (closed system) initially at at 163 °C and 9.00 bar undergoes an irreversible, adiabatic process until the final pressure is 7.00 bar. The work done during the process is -335 J. Calculate ΔSsys and ΔSsurr for the process. CPm = 22.7 J/(K mol)