Physical Chemistry Answers

An alloy with density 2.85 g/cm³ consists of 93.7% Al and 6.3%Cu by mass. 0.691cm³ of alloy reacts with HCl(aq). If all Al and none Cu reacts with acid, find mass of H2 obtained.

Combustion of 0.2g carbon-hydrogen-oxygen compound yields 0.2998g CO2 and 0.0819g H2O. Find percentage composition and empirical formula of the sample

Find empirical formula for a sugar with 44.77%C, 7.52%H, 47.71%O.

Find moles F atoms in 75ml sample of haloethane (C2HBrClF3) (d=1.8711g/ml)

prepare 250 ml of 0.5 m phosphate buffer of ph 7.6 give that pka = 7.21 using the equimolar method. to prepare the same, first prepare stock a 250 ml of 0.5 m k2hpo4 and stock b 250 ml of 0.5 m kh2po4. then calculate how much of these you would mix to prepare the final buffer. given: mw of k2hpo4 = 174.18; mw = of kh2po4 = 136.08

Potassium 40 has percentage abundance of 0.0012%. How many atoms of potassium 40 are present in 225ml of milk containing 1.65 mg K/ml?

For the reaction that takes place as A (g) +1/2 B (g) → 20 (g), it is reported that the reactants are fed at a stoichiometric rate at a volumetric flow rate of 20 dm3 / s at the beginning of the reaction. The reaction takes place isothermally desired at a total temperature of 100 atm and 200 ° C. Reaction rate expression:

-ra = ((k1 * Ca) + k2 * Cc) / (k3 * Cb) as k1 = 20 1 / s and k2 = 20 1 / s and k3 = 20 dm / mol . Two reactors from one CSTR and one PFR are targeted for the process, where the highest conversion value is aimed to be 80%. The PFR volume is approximately 12 times the CSTR volume. In light of this information:

a) Show the product and reactant concentrations in the graph as the name of the conversion.
b) Show and prove the most suitable reactor credit?
c) Once determined 1. Find the conversion value at the reactor outlet?
d) Find the total volume of the reactors?

That's it: Reaction A <-> B in liquid phase is processed in a sequence of adiabatic PFR-type series reactors, with equimolar feeding of the reagents, at 15 ° C in the first reactor. Determine the minimum number of coolers required for the final conversion to be 80%. Consider that these chillers lower the outlet current temperature to 310K and that 92% of the equilibrium conversion is achieved in each reactor.
∆h° a= 32000 cal/mol, ∆h° b= -70000 cal/mol, cpa= cpb = 37,2 cal/g mol .k and Ke= 37

Assuming all outer toms are the same a binary molecule of the AX6 type is polar or nonpolar

One mole of an ideal gas (group 18) at 27 ℃ and 1 atm expands adiabatically from a volume of 10 dm3 to 20 dm3. Calculate:
(i) q
(ii) w
(iii) ΔU
(iv) ΔH
(v) Final temperature of the gas.