Doc

This page lists questions and answers that were posted by visitors named Doc.

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The following questions were asked by visitors named Doc.

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The following answers were posted by visitors named Doc.

2. plasma 6. all of the above rest correct
12 years ago
The answer is 6. The rooms could just have well been labeled A, B, C. 6-4=2 Room A 6-4=2 Room B 6-4=2 Room C 2+2+2=6 or since all but 4 are going into each room, the 4 going into other rooms are split equally into 2 and 2.
12 years ago
1. Question : Which of the following is an impact of increased ocean acidification as caused by global climate change? Student Answer: CORRECT Low pH seawater alters calcium carbonate concentrations which reduce the ability of many animals to build shells...
10 years ago
Convert gram values given to moles. (moles = mass / f.wt), then divide the mole values by respective coefficients... the smaller number is the limiting reagent. Moles N2 = 5.42/28.02 = 0.193; Moles H2 = 5.42/2.02 = 2.68 => compare N2(0.193/1) and H2(2.68/...
8 years ago
The reaction is a 3 to 1 ratio Pb(NO3)2 : Al2(SO4)3 => moles aluminum sulfate = 1/3(moles lead nitrate) => 1/3[(0.02549L)(0.1338M)] = 0.00114 mole aluminum sulfate => Therefore, concentration = [Al2(SO4)3] = 0.00114 mole/0.02549L = 0.045M Aluminum Sulfate...
8 years ago
1. Write and balance equation 2. Convert given solution data to moles solute ... moles = Molarity x Volume in Liters 3. Apply moles reactants to balanced equation (divide each mole amount by respective coefficient => Limiting Reagent) 4. Using moles of Li...
8 years ago
You'll need the average density of whole blood. (~1060 Kg/m^3) take 0.100% of this and convert to grams/L.
8 years ago
Faraday's Law... 1 mole electrons = 96,500 amp-sec. => ?gAg = 5amps(1mol e/96,500amp-sec)(1 mole Ag/1 mole e)(107g Ag/1 mole Ag)(60sec/min)(50min) = You punch it into your calculator.
8 years ago
Use Ideal Gas Law (PV=nRT & n=PV/RT)=> moles of O2... Divide by 2 => moles of KClO3 ... Multiply moles KClO3 by formula wt of KClO3 => grams of KClO3 decomposed. Be sure all data is converted to same units as R-value. I get 0.021 gms KClO3. Good luck.
8 years ago
See 10:14pm post.
8 years ago
Calculate dry wt of Calcium Carbonate without watch glass... Then, ratio [CaCO3(s) / tablet mass] x 100% => Wt% CaCO3 I get 55.4% w/w.
8 years ago
See 6:36pm post by Sam.
8 years ago
Correction... I'm used to decomposing KClO3, should of used f.Wt. of KClO4 = 138g/mole... Same logic applies to all else. Moles KClO4 decomposed = 0.0017mole O2, then => I get 0.235g KClO4 decomposed ... Sorry bout that.
8 years ago
correction-2 => 0.0017 mole KClO4! not O2.
8 years ago
1 mole of any gas occupies 22.4 liters at STP.
8 years ago
Same as in your 2:27pm post
8 years ago
just use v(rms) = (158)[SqrRt(T/M)] meters/sec ... T = Kelvin & M = gms/mole ... 158 is from SqrRt[(3)(8.314)(1000)] ... These are constants factored out of the original equation v(rms) = SqrRt(3RT/M).
8 years ago
1. Use ideal gas law to determine moles of ProAm. Be sure to convert given data to units of R-Value. 2. Determine concentration in 0.500L soln. =[moles ProAm/Volume(L)]. 3. Determine [OH]=SqrRt([ProAm]Kb) 4. Determine pOH=-log[OH] 5. Determine pH=14-pOH (...
8 years ago
P(1) = 745mm P(2) = 0.115atm(760mm/atm)= 87.4mm V(1) = 414ml V(2) = ? T(1) = 24C = 297K T(2) = -95C = 178K (PV/T)1 = (PV/T)2 Substitute above data into equation and solve for V(2).
8 years ago
(1)Ca. Moles H = Molarity x Volume(L) = 0.005L(0.0983M)HCl = 0.00049 mole HCl in 50ml of solution. Now, covert to [HCl] = (moles HCl)/(Vol. Soln in Liters) = 0.00049mole/0.050L =0.0098M in HCl => [H]=0.0098M. (2) pH = -log[H] = -log(0.0098) = 2.01
8 years ago
[mc∆T]Cu + [mc∆T]HOH = 0 [mc(Tf - Ti)]Cu + [mc(Tf - Ti)]HOH = 0 All data is given in problem except T-final. Solve for Tf. m(Cu) = 33.2 gm m(HOH)= 50.0 gm Ti(Cu) = 70.5 C Ti(HOH)= 25.0 C Tf = ??? c(Cu) = 0.385 J/gC c(HOH)= 4.184 J/gC Your answer should be...
8 years ago
If pH(1) = 1.7 => [H+]=10^-1.7 = 0.020M If pH(2) = 1.7 + 1.4 = 3.1 => [H+]=10^-3.1 = 0.0008 pH(1)/pH(2) = 0.020/0.00080 = 25X dilution If pH(3) = 2.2 => [H+]=10^-2.2 = 0.0063M If pH(4)= 2.2 + 1.4 = 3.6 => [H+]= 0.00025 pH(3)/pH(4)= 0.0063/0.00025 = 25X di...
8 years ago
Using the Henderson-Hasselblach equation => Salt to Acid Ratio =[NaHCO3]/H2CO3] = 0.238/1. Thus, for a .1M H2CO3 the buffer would be 0.0238M in NaHCO3. => grams of NaHCO3 needed = 0.0238 mole(84 g/mole) = 20 grams. Adding 0.02mole HCl to the buffer soluti...
8 years ago
Heat flow in problems like this use q = mcT if a temp change is observed, and q = mH if a phase change is occurring. Here m = mass of substance gaining or losing heat, c = specific heat of substance, T = Temp change and H = Transition Constant for phase c...
8 years ago
Convert given data to moles, relate to the reaction ratios, then convert back to grams. a) for 0.12g Ag = 0.0011mole Ag => produces 1/2(0.0011mole) Ag2S => (0.00056mole)(248g/mole) = 0.138g Ag2S b) assume an excess of H2S is present, then the rxn will req...
8 years ago
You need to review the Aufbau Diagram. It shows the order of electron entry for the building up process. For Mo, it is in the 5th row of the periodic table => Mo:[Kr]5s^24d^4 ... for Mo(+3), ionization of transition metals always starts from the valence l...
8 years ago
Try V(rms)= [158 x SqrRt(T/M)]m/s T = Temp in Kelvin M = Molecular weight
8 years ago
4p holds 5 electrons in the ground state with two orbitals having paired electrons and one orbital have an unpaired electron. Br:[Ar]4(s^2)3(d^10)4(px^2)4(py^2)4(pz^1)
8 years ago
Solubility in pure water of all 1:2 or 2:1 ionizations with Ksp values is => Cube-Rt(Ksp/4). For Ca(OH)2 ; Ksp=6.5E-5 Solubility = Cube-Rt(6.5E-5/4) = 0.0118M in Ca^+2 and 2(0.0118M)in OH^-. In pure water (no common ion effect) the following can be used t...
8 years ago
0.60M HF/1.00M KF Buffer Soln Before adding OH- or H+, Ka=[H+][F-]/[HF] => [H+]=Ka[HF]/[F-] => [H+]=4.2E-4(1.00)/(0.60) => [H+]=0.0007M in H+ => pH=-log(0.0007)=3.15 HF => H+ + F- 0.60 x 1.00 Adding 0.08M NaOH Shifts Equilibrium Right, decreasing HF by 0....
8 years ago
Sulfur combines with H+ => H2S(g) and shifts the solubility equilibrium toward more ionization and increased solubility. The formation of H2S essentially is removing S-2 from the solution forcing the metal-sulfide to decompose in order to replace the sulf...
8 years ago
Zn + 2HCl => ZnCl2 + H2 Moles Zn = (4.25g/65.37)= 0.065mole Zn available. Moles HCl = 25ml(3M HCl) = 0.025(3) mole HCl = 0.075 mole HCl HCl is limiting reagent => Only 1/2(0.075 mole)Zn = 0.0375 mole Zn will be consumed in reaction => (0.065 - 0.0375)= 0....
8 years ago
C2H6 + 7/2O2 => 2CO2 + 3HOH moles O2 consumed permole C2H6 = 7/2 mole = 3.5 moles O2 per mole C2H6.
8 years ago
What was wrong with the solution I posted on this same problem? => Tuesday, April 18, 2017 at 9:35pm
8 years ago
Rate Factors => C.A.N.T.C. C => Concentration Effects of Reactants A => Area (Surface Area) N => Nature (Chemical Structure) T => Temperature and Energy Contents C => Catalytic Effects Rxn Rate = f(Rate Factors) => Rate Laws
8 years ago
Drawing lewis structures 1. Calculate Valence Number (total #valence electrons - from group number) 2. Calculate Octet Number (total #electrons after bonding - always 8 (nonmetals) except for hydrogen and complex substrates => 2) 3. Calculate Bond Number...
8 years ago
The !-X is supposed to be over and under the A.
8 years ago
Did this help?
8 years ago
Be sure to check your ion concentrations in the Nernst Equation are raised to the proper power. Cell [Cr/Ni^+2[0.010M]//Cr^+3[0.875M]/Ni] Q = [Cr]^2/[Ni]^3 = (0.875)^2/(0.010)^ = (0.766)/(1.0E-6) = 7.66E+5 E^o = E(Redn) - E(Oxdn) = (-0.23v)-(-0.74v) = 0.5...
8 years ago
There's only one way a Cr/Ni Rxn can go... Cr([email protected]) => Ni([email protected]) => Std Cell = 0.51v For non-Std Cell => [Cr/Ni^+2[0.010M]//Cr^+3[0.875M]/Ni]; n=6 2Cr + 3Ni^+2 => 2Cr^+3 + 3Ni Q = ([Cr^+3]^2/[Ni^+2]^3) Apply to Nernst Equation => E(Non-Std) =...
8 years ago
Since cell is Cr/Ni, it shouldn't have to say it's spontaneous. The thing that's missing is the standard cell voltages. With that it's spontaneous.
8 years ago
Since cell is Cr/Ni, it shouldn't have to say it's spontaneous. The thing that's missing is the standard cell voltages. With that it's spontaneous. Flow is spontaneous from more negative to more positive electrode potential.
8 years ago
Using Standard Heats of Formation and Standard Entropy values at 25C apply to free energy equation => ∆G(f) = ∆H(f) - T∆S ∆H(f) = -220.1 Kj/mole (direct from thermo properties table) ∆S = -47.34 KJ/mole-K (from Hess's Law)* T = 298K *=> C + 1/2(O2) + Cl2...
8 years ago
Great Scott!
2 years ago