help on ap chem..please....

<p>ok..recently as im taking ap chem..i am feeling a little bit dumb...
this question im asking you is not very hard...but...i guess im dumb...</p>

<p>tow flasks are connected by a stopcock. the 5.0L flask contains CH4 at a pressure of 3.0atm, and the 1.0L flask contains C2H6 at a pressure of 0.55atm. Calculate the total pressure of the system after the stopcock is opened. Assume that the temperature remains constat..</p>

<p>any response would be appreciated..</p>

<p>also i want to see i got another problem right.. can anyone check?</p>

<p>write the formulas to show the reactants and the products for the laboratory situations describe below.in all cases a reaction occurs. assume solutions are aqueous unless otherwise indicated. represent substances in a solutions as ions if the substances are extensively ionized. omit formulas for any ions or molecules that are unchanged by the reaction, and balance the equation.</p>

<p>a)cadmium metal is placed in a solution of tin(II) chloride
--> Cd+SnCl2->Cl2Cd+Sn
B)Magnesium pellets are placed in 1.0M hydrocholoric acid.
--> Mg+2HCl->MgCl2+H2
C)Sulfur in its standard state is burned in air
--> S+O2->SO2
D)Solutions of silver nitrate and sodium cholride are combined
--> Ag+NaCl->AgCl+Na
e)solid iron(II) sulfite is heated strongly
--> Fe+O2->FeO2</p>

<p>am i right on this problems..?i dont have the answers...so..</p>

<p>anyone???????please...</p>

<p>It's CdCl2</p>

<p>Fe 2+ ion</p>

<p>so it would be</p>

<p>Cd+SnCl2->CdCl2+Sn</p>

<p>and what do you mean by Fe2+ion..</p>

<p>no one........</p>

<p>Too tired at the moment for the first one... but among the lettered problems:</p>

<p>For C it forms SO3, not SO2, and it's S8, not just S. Well that's what it is, but I'm not sure if they want you to be that specific, in which case S would work too. But otherwise, it should be S8 + 12O2 --> 8SO3</p>

<p>D is
Ag + Cl --> AgCl (s) Silver chloride is insoluble. Silver nitrate and sodium chloride are soluble, and so is sodium nitrate.</p>

<p>Last one it's not Fe, it's FeSO3. I'm not entirely sure about the reaction though.</p>

<p>"tow flasks are connected by a stopcock. the 5.0L flask contains CH4 at a pressure of 3.0atm, and the 1.0L flask contains C2H6 at a pressure of 0.55atm. Calculate the total pressure of the system after the stopcock is opened. Assume that the temperature remains constat.."</p>

<p>I won't calculate this for you but...</p>

<p>When the stopcock is released, the volume of the entire apparatus is equal to the sum of the two flasks. The law of partial pressures states that the identity of the each gas is retained and makes up the total pressure. Just use the equation P1V1=P2V2 (inverse relationship between pressure and volume aka Boyle's Law) to find the partial pressure of each gas and add them. For instance, for CH4, it would be 5.0L x 3.0atm = (5.0L + 1.0L) x P2(in atm). Solving for P2 gives you the partial pressure of CH4 after the gases are allowed to mix. Do this for C2H6 and you're done.</p>

<p>It's
FeO2 (s) --> Fe (l) + O2 (g)</p>