Physical Chemistry Answers

128 grams of oxygen reacted. After the combustion of an unknown hydrocarbon, the total pressure of a 18.91-L container is 7.3347 atm at 22.7 degrees celsius. What is the hydrocarbon?

is it true that hydrogeyn bonding is responsible for the polar nature of the water molecule?

O2 molecules can dissociate to form O atoms by absorbing electromagnetic radiation. If it takes 489 kJ to dissociate one mole of O2 molecules to form two moles of O atoms, what is the frequency of the light that would have just enough energy to decompose a single O2 molecules into O atoms?
a) 1.25 x 10^15 s^-1
b) 8.27 x 10^-19s^-1
c) 7.52 x 10^38s^-1
d) 8.0x10^-16s^-1
e) 5.72 x 10^16s^-1

the osmotic pressure of a solution is 3.2,which contains 45gm of sucrose in per liter of solution in 20 degree celcius calculate R

'A(aq) 2 B(aq)-----> AB 2 (aq) suppose that 40ml of .0116 M A(aq) is mixed with 50ml of .0202 M B(aq) and after the reaction .000375 moles of AB2 were obtained calculate the moles of A and B before the reaction

Sandra has 500g of water boiling at 99 celsius (C), her recipe calls for water to be at 78C, ice is at 0C, how much ice must she add to cool down the water?

Hi! i don't know English very well!(excuse me because of that!)
my question : when we pour alcohol into water to dissolve them, first seconds alcohol is unclear and a bit translucent. why?

conjunction with 2.1 g of iron with sulfur separated 3.77 kJ. calculate the heat of formation of iron sulfide