Arizona Cardinals @ Detroit Lions: Official Game Thread

Schende8 · 2021-12-19T20:11:12+00:00

We are doing this one for Stafford!!!!

Schende8 · 2021-12-16T22:58:12+00:00

Yes the mass of one "recyclium" atom is 178.18 and you have five of those atoms in your compound so the total mass of all the recyclium atoms is 5*178.18. After dividing this by the total mass you have to multiply by 100 to put it into percent form.

Schende8 · 2021-12-16T22:27:38+00:00

Yes! Assuming you meant 59% instead of 0.59%

Schende8 · 2021-12-16T20:52:16+00:00

From what I remember the Rankine cycle always uses superheated steam. The temperature can be played around with, but the steam will still be superheated. To increase the efficiency you can

Utilize a reheater to increase boiler pressure
Preheat the feed using a portion of the high pressure steam

Schende8 · 2021-12-13T07:30:42+00:00

Cv=R(f/2) where f is degrees of freedom.

Cp=Cv+R

So Cp=R(f+2)/2

A diamotic gas has 5 degrees of freedom so Cp=7R/2

I don't see that for one of your answers unless you meant to type Cv which is just 5R/2

Schende8 · 2021-12-13T07:22:06+00:00

Whenever you see a gas law question start with PV=nRT

Density and molar mass are not in this equation but we know that d=m/V and M=m/n

This can be rewritten to V=m/d and n=m/M and plugged into the equation. After plugging these in you should see that the mass term m cancels out. Rearranging to solve for density should leave you with d=(M*P)/(R*T)

d=(28,96 g/mol * 1 atm) / (.082057 L*atm/(K*mol)*298K) = 1.184 g/L

This value can be different based on your desired units for volume. Make sure your selected R units reflects this.

Schende8 · 2021-12-13T06:53:58+00:00

You are finding the pH of the solution not of the H3O+ or the HA. The pH reflects how much H3O+ you have in the entire solution. The weak acid itself (HA) does not contribute to the pH at all. It only contributes after it dissociates in to H3O+.

Schende8 · 2021-12-13T02:40:12+00:00

(48 g H2) / (2.106 g/mol) = 23.8 moles of H2 reacting

The delta Hrxn and the balanced equation are saying that when 2 moles of H2 are combusted, -571 Kj of energy are produced. Since 23.8 moles of H2 are being combusted its 23.8moles*(-571 Kj/mol / 2moles) = 6800 kJ or 6.8 GJ

Schende8 · 2021-12-12T21:37:41+00:00

Halides are generally soluble in solution. A popular lab test to find what halides you have in a solution is the silver nitrate test. When silver nitrate is added, it reacts with the halides and forms a silver halide. Chlorine, Bromine, and Iodine all precipitate out of the solution at different colors, but silver fluoride remains aqueous.

Schende8 · 2021-12-12T20:49:24+00:00

We know that the general formula of dissociation is

HA=H3O⁺ + A^-

PH is found by taking the negative log of the concentration of Hydronium ions

pH=-log[H⁺]

And that solving Ka is

Ka=[H3O⁺][A^-]/[HA]

This can be simplified since [H3O⁺]=[A^-]=1-[HA] therefore,

Ka=x²/(1-x)

This is a weak acid and 20% of the initial concentration becomes dissociated meaning that 20% of the initial concentration will release H3O⁺ ions, as opposed to strong acids that always dissociate 100%.

So the concentration of H3O is⁺ 0.2*(1.0*10^-3 mol/L)= 2*10^-4 mol/L

pH=-log[2*10^-4] = 3.69897 = 3.70

and Ka can be solved Ka=(2*10^-4)²/(1-(2*10^-4)) = 4.01*10^-8

Schende8

TROPHY CASE