Shenaya
Most popular questions and responses by Shenaya
Inorganic Chemistry
Can Cu2+ oxidize 1) SO2 2) C2O4(2) Does this happens also when the solution is basic? Cu2+ + H2S > CuS + H2
asked on June 14, 2017 
Chemistry
1)In the reaction O2+2F2> 2 OF2, F2 is the oxidizer. 2)F can't have positive oxidation states. Does 2 explains the reason for the 1st one or is it because because of F's higher electronegativity?
asked on July 31, 2017 
Chemistry
We have been thought that BaC2O4 is a precipitate when dissolved in H2O. When comparing its solubilty in water and in an aqueous acidic solution,what is the reason for its higher solubility in an aqueous acidic solution than water?
asked on July 9, 2017 
Inorganic Chemistry
What will happen if we add Mg powder to a (NH4)2SO4(aq) solution? What would be the products?
asked on June 19, 2017 
Can't submit follow up questions or thank the tutor
I can't submit a follow up question or thank the tutor after an answer or a response is posted by a tutor,as the "post answer" button not available in the bottom of the form,as it used to be. I tried reopening,refreshing the browser and switching the
asked on July 30, 2017 
Organic Chemistry
Does Ethanoyl Chloride gives out a white precipitate with aqueous AgNO3? We've been thought that an acid chloride gives out the relative Carboxylic acid with water.So in the same way can we take that Ethanoyl Chloride reacts with the water in this aqueous
asked on July 11, 2017 
Math
The equation 2x^2+2y^2+x+4y+2c=0 represents a circle.(let's name it S1) 1)Find the values of a,b and and show that c
asked on July 31, 2017 
MathematicsIntegration
Question: Prove that [integrate {x*sin2x*sin[π/2*cos x]} dx] /(2xπ) } from (0π) = [ integrate {sin x*cos x*sin[π/2*cos x} dx ] from (0π). My thoughts on the question: We know that integrate f(x) dx from (0a) = integrate f(ax) dx from (0a) From
asked on June 8, 2017 
Chemistry
Question: A solution of H2X of unknown concentration is given. pH of the solution is 4. ka1=2*(10)^6 M ka2=1*(10)^11 M Find the concentrations of [H2X] ,[HX] and X^2 in the solution. My thoughts on the question: The temperature which the solution is
asked on May 31, 2017 
Mathematics binomial theorem
How do we find the value of(1.01)^5 approximately up to three decimals,only with the use of the Binomial theorem?
asked on May 24, 2017 
Chemistry
Question : State whether the following are true or false. SO2 gas changes the colour of a KMnO4(aq) solution They have taken this as false and given the following equation: SO2+H2O+2KMnO4>K2SO4+MnSO4+H2SO4 (not balanced) But why they have taken this as
asked on July 29, 2017 
Organic Chemistry
What will happen from the following if H3CC6H6N2Cl is treated with Na2CO3? a)CO2 will emit 2)NH3(g) will emit c)N2ClC6H6CH3 will be produced d) NH2C6H6CH3 will be produced We get C6H6NH2 when Sn/conc.HCl are reacted with Nitro Benzene.This become
asked on June 12, 2017 
Mathematics
State whether this infinite series converges or diverges? 1+(t) + (t^3)+...... t=[(5x+6)/(3x2)] My thoughts on the question: The sum of 'n' terms in a geometric progression is a[r^n  1]/(r1)(let's calk this 1), where r>1 and when r
asked on June 8, 2017 
Chemistryksp and kb
We were given a 0.1 M KOH solution.25cm3 of that solution is taken and 5g of MX precipitate is added to that.X is an anion of a strong acid. Kb for MOH=2*(10)^5 Ksp for MX= 3*(10)^6 M 1)find the [M+] in the solution 2)Find the [X] concentration and pH
asked on May 24, 2017 
Physicscan someone check thjs question?
cgi?id=1501763622#1501763622.1501764356
asked on August 4, 2017 
Physics
The speed of light in vacuum depends on, 1)wavelength 2)frequency 3)intensity 4)temperature 5)none of the above I know that 1 and 2 are correct. What about the others?
asked on August 3, 2017 
Chemistry
Order the following considering their boiling point in an aqueous solution. 1) pentan2one 2) pentan2ol 3) 2aminopropanoic acid The answer key says the order (increasing) is, 1 < 2 < 3 and states 1 only have weak permanent dipole dipole forces and Van
asked on July 28, 2017 
Chemistry
If we wish to find the molar mass of a pure solid organic compound, which measurement would be most useful and why? A)melting point of the solid B)melting point depression of the mixture of the solid with 1,4dichlorobenzene C)Heat of combustion
asked on July 26, 2017 
Chemistrytitrations
Question: An unknown mass of (NH4)2CO3 is mixed with 4g of NaOH and dissolved in 100cm3 of water,which results a clear solution.Gasses are removed by heating the final solution. 2 parts of 25cm3 of final solution is taken and one is titrated with 0.5 M HCl
asked on May 29, 2017 
Math
Find the greatest value of a,so that integrate [x*root{(a^2x^2)/(a^2+x^2)} ] from 0a
asked on August 1, 2017 
Chemistry
When comparing the boiling points of two compounds,one is a gas and the other is a liquid,is there anything like the liquid will have a lower boiling point than the solid? The molecular mass of the liquid is lower than the solid and they have the same type
asked on July 31, 2017 
A suggestion @Writeacher
I don't know whether suggestions are welcomed,but I would like to express what I feel about this change and hope anyone won't misunderstand this as being rude. From my point of view this change will be causing some difficulties to students and also
asked on July 30, 2017 
Chemistry
What should be the pH value of the solution to double the solubility of the ionic compound NX? Ka of HX=2*(10)^5 M My thoughts on the question: Let the solubility of NX=x M 1) NX(s) N+(aq) + X(aq) eq:con: x x (moldm3) X^ HX + OH^ >(2) HXH^+ + X^
asked on July 12, 2017 
Chemistry
When a concentrated NaCl aqueous solution is electrolyzed, what is the reason for the stabality of the products to be lesser stable as of thermodynamically, with respect to the reactants? Is it because the products are gasses? H20(l) +4e>H2(g) +
asked on June 19, 2017 
Chemistry to DrBob222
Regarding my question on display.cgi?id=1496901710(I can't post URLs) Can we apply the formula PM=dRT seperately to the systems before and after being heated,and solve this one?
asked on June 14, 2017 
MathematicsIntegration
Question: For any positive integer n,show that integrate.[(sin x)^2n dx ] from o  π/2 = [(2n)!*π]/[(2)^(2n+1)*(n!)^2 ] What I thought: Let I =int.[(sinx)^2n dx] And again I= int.[ (sin(π/2x))^2n dx] = int.[ (cos)^2n dx] 2I= int.[(sin x)^2n + (cos
asked on June 12, 2017 
Math
Show that for real x that {[cos x + 2 sin x + 1]/[cos x + sin x] } cannot have a value between 1 and 2. Let y = [(cos x+2 sin x + 1)/(cos x + sin x) ] y(cos x + sin x) = (cos x + 2 sin x + 1) sin x(y2) + cos x(y1)=1 , I just feel that this isn't the way
asked on August 1, 2017 
Chemistry
Does a neutral solution always act as a buffer solution?
asked on July 31, 2017 
Chemistry
Do the reaction rate depends on the concentration of catalyst? I googled this and found that the decomposition of H2O2 stops of we add excess MnO2. Are there any other examples like this? Or does this happens with every catalyst when they are in excess or
asked on July 31, 2017 
A suggestion  @Writeacher
I forgot one main thing:it would be a great help for us students,who use phones,if we are allowed to post the link to our original questions. Thanks again!
asked on July 30, 2017 
To @Writeacher
Yes,I used my phone to access this site from the very first day because I'm far from home due to my studies and usually I use my phone to get help with my studies.And it wasn't until yesterday this happened. So will I have to post it as a new
asked on July 30, 2017 
Chemistry@DrBob222
I apologize for having to bother you again,but I still can't post follow up questions and I can't find the reason.I even tried reinstalling the browsers,and still the same. Anyway you responded to my last post regarding H2 O2 fuel cell, "I agree". So did
asked on July 30, 2017 
Chemistry
If we were asked to order SO2,H2O,CuO and CaO considering their acidity, how do we find what is more acidic from CaO and CuO?
asked on July 27, 2017 
To DrBob222
This is regarding the Biochemistry question postef by Grace.. I'm wasn't able to mention this in the subject section due to the large no.of characters! I apologize for any inconveniences made! In this case,to calculate pH of the solution, we should find
asked on July 23, 2017 
Physics
A hemisphere of radius r is placed on a horizontal plane and a small mass of "m" is placed on the top of the hemisphere. Find the height from the ground to the mass m,at the moment it loses it's contact with the hemisphere.And the contact is frictionless.
asked on July 11, 2017 
Chemistry
How do we order the following considering their acidic nature? 1)CH3COOH 2)Phenol 3)C6H5COOH 4)CH3C(triple bond)CH 5)a cyclic alcohol [ (CH2)5CHOH ] I know that Phenol is acidic than alcohols and Carboxylic acids are acidic than alcohols and the alpha H
asked on July 10, 2017 
Chemistry
With which of the following AgNO3 makes a precipitate quickly? And what would be the reason? 1) C6H5Br 2)C6H5CH2Br 3)(CH3)3CBr 4)C6H5CH2CHBrC(triple bond)H 5)C6H5CH2BrCH=CHCH3 I feel like that 1st one is most probably,not the answer as it is not
asked on June 29, 2017 
Organic Chemistry
We are asked to order the following compounds considering their hydrolysis. 1)CH3COCl 2)CH3COC2H5 3)CH3CON:H2 4) CH3COOCH3 What are the main factors which determine how easily they tend to hydrolysis?
asked on June 18, 2017 
Chemistry Henry's Law
Why Ammonia is a deviation from the Henry's Law,when it is dissolved in water? Does that has anything to do with Ammonia having Hydrogen bonds? Or what could be the reason?
asked on June 12, 2017 
Chemistry
Under special conditions D2 is reacted with Ca to make CaD2.What would result if D2 is reacted with H2O?
asked on June 12, 2017 
Chemistry
What is more basic KO2 or KOH? I know that KO2 is also craeted this way; KO2 + 2H2O > 2 KOH + H2O2 + O2 I think,as KOH is created by this reaction and KO2 being a raectant, the compounds created should have less strong,more stable characteristics when
asked on June 12, 2017 
Chemistry  percipitates
10g of AgI is dissolved in 100cm3 of water and Na2SO4(s) is added to the solution with the ppt.After about 10mins.25cm3 of the solution is taken and added Cl2 and heated.The remains Cl2 is removed and a small amount of KI(s) is added and then the solution
asked on June 12, 2017 
Mathematics Integration : to Steve
But how do we integrate ln1+tanx da X=theta =int.[lncos xdx] +int.[sin x dx ]  int.[lncos x dx] ?
asked on June 9, 2017 
MathematicsIntegration
Using a suitable substitution show that integrate {[ln1+x]/[1+(x)^2]} from 01 = (π/8)ln2 On this one, I don't really have any ideas of going forward solving this.I don't see a substitution which will simply the integral.
asked on June 9, 2017 
Mathematics  Complex numbers
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asked on June 8, 2017 
MathematicsComplex Numbers
Question: If z1 , z2 ,z3 are complex numbers and z1=z2=z3=1 and (z1)^3+(z2)^3 + (z3)^3 +z1*z2*z3=0 find the maximum and minimum values of z1+z2+z3. My thoughts on the question: Let z1=a , z2=b and z3= We know that a+b+c
asked on May 31, 2017 
ChemistrypH
Question: v cm3 of a 0.2 M HX solution and v cm3 of 0.1 M KOH solution is mixed.pH of the final solution is 5.3 1)Find ka of HX 2)Find the moles of NaOH and HCl should be added respectively,for the pH of 1dm3 of the solution to increase and decrease by 1
asked on May 31, 2017 
ChemistrykD
A chemical "X" is included in a water in a pond. 1)5dm3 of water from the pond is taken and is mixed with 200cm3 CHCl3.Then CHCl3 layer is taken out separately and left to vaporize. Then the remaining mass of X is measured.There was 10mg. 2)The remaining
asked on May 29, 2017 
Physics
A man climbs down a rope which is connected to a tree.The breaking stress of the rope is 75℅ of his mass.Find the maximum acceleration he can climb down the rope? Does the breaking stress here acts as the tension(T) If so by applying F=ma downwards, mgT
asked on August 3, 2017 
Physics
Inside a box(mass "M"), a light string "X" is atthached to it's bottom and the other end of the string is attached to a mass "m"(this makes a pendulum). This system is attached to the point O(the center of gravity of the system), by a string " Y" and moved
asked on August 3, 2017 
Mathto Steve
I posted a followup question to your response at my post available at, display.cgi?id=1501575066 Hope you saw it! Thank you!
asked on August 3, 2017 
Chemistry
How do we order the folllwing considering how easily they grab H^+ ions, when dissolved in liquid ethanoic acid? 1)OH^ 2)F^ 3)Cl^ 4)Br^ 5)I^ I think the correct order is 5
asked on July 31, 2017 
Chemistry
Why do Chloroethanoic acid(s) do not hydrolyze? Is it because it they has(have) Cl atom(s)? But the NH4^+ ions in NH4Cl do hydrolyze. What is the reason for this difference?
asked on July 31, 2017 
Chemistry
State whether the following statements are true or false. The importance of using H2 O2 cell in jet engines; a)because it doesn't release gasses which cause Greenhouse Effect b)because it doesn't release gasses which cause Ozone layer depletion The answer
asked on July 29, 2017 
Mathintergration
Show that integrate.[e^(4x)*(cos 3x)] from 0infinity =4/25 I got the answer(without applying limits) as, {(e^(4x) )[3sin(3x)  4cos(3x)]}/25 But when applying the upper limit what is the value of, {(e^(infinity) )[3sin(3*infinity) 4cos(3*infinity) ]
asked on July 29, 2017 
Math
7 men are 5 women are seated in a row.Find the ways they can be sated so that two women are not together. Starting with a man, the ways=(7!*5!)*2!,multiplied by 2! because we can reverse the way seated. Starting with a woman,
asked on July 28, 2017 
Math
Is there any method to calculate the value of (1+i)^n + (1i)^n , without using the binomial theorem or Euler formulation? As (1i) is the conjugate of (1+i) we can take the value of (1+i)+(1i)= real part of (1+i) But how to avoid Euler formula?
asked on July 28, 2017 
Physics
A rope kept on a horizontal plane moves with a constant acceleration. If a constant force "f" acts on the rope,the tension of the middle of the rope is T. Which of the following are true? a)If the rope has a weight,T/f=1/2 b)If the rope is light,T/f=1 c)If
asked on July 27, 2017 
Chemistry
If we are given the ksp of AgCl at 14°C and 42°C,how do we find the ∆H° for the dissociation of AgCl(s)?
asked on July 26, 2017 
Chemistry
Why can't we apply Kd directly to a equilibrium solution of CCl4 and H2O,with CH3COOH dissolved? Do CH3COOH form polymers in CCl4? or are their single molecules of CH3COOH in CCl4?
asked on July 26, 2017 
Chemistry
How do we order the following,considering their stability when they are in (+3) oxidation state? Al Ga Tl Sc We've been taught that (+3) is the common oxidation state of Sc. And when it comes to Al ,Ha,Tl how do we order them?
asked on July 24, 2017 
ChemistryIdeal gases
Can we convert an ideal gas into a liquid?
asked on June 19, 2017 
Chemistry
What is more acidic from [CuCl4]^(2) and ethanoic acid? And what is the reason?
asked on June 19, 2017 
MathematicsIntegration
Question: f(x)=ax^2 + bx + c {a,b,c €R} When 0
asked on June 12, 2017 
MathematicsIntegration
How do we integrate {[1/(√(1x^2) )]*[ln(2x+3)(√(1x^2))] } ? Is there any suitable substitution or do we have to do this by parts? I don't have any idea to proceed on.
asked on June 12, 2017 
Chemistrytitrations
When an acid is titrated with a Carbonate, do we have to heat the system when Hph is the indicator? If so what is the reason?
asked on June 12, 2017 
Chemistry
Question: At 300 K,Carbon powder and O2 are included in container of 10dm3.When the system is heated well,all the O2 converts into CO2.Then the system is cooled to the initial temperature. The volume of the Carbon powder is negligible. Find the percentage
asked on June 8, 2017 
Chemistry
Question: 50cm3 of 0.4 M Ba(OH)2 and 50cm3 of HA of unknown concentration is added together.At 25°C,pH of the solution is 9.With appropriate assumptions calculate the [HA] and ka of HA. My thoughts on the question: There are more than one approach which
asked on May 28, 2017 
Calculus
How do we integrate [(cosx)^2(nx)(sin(nx))]/[a(cos(nx))] dx?
asked on May 27, 2017 
MathsComplex numbers
If z is any complex number where z=1,show that using the Argand plane 1
asked on May 23, 2017

physics
Hope you've heard about equations of motion. For this one we can use v=u+at , where v=final velocity(in m/s) , u=initial velocity(in m/s) , a=uniform acceleration(in m/S^2) and t=time(in seconds). Now substitute values for the above equation to find the
posted on December 1, 2017 
Chemistry
Moles of Na3PO4 = 5.45 g/molar mass of Na3PO4 g/mol Let the volume of the Na3PO4 solution be=v dm^3 1.86 mol/dm^3 * v dm^3 = moles of Na3PO4 Hope this helps..
posted on December 1, 2017 
Chemistry
I hope you may have learned about the Ideal gas equation(PV=nRT), where P=Pressure of the gas , V=Volume of the gas , n=amount of gas/substance(in moles) , R= Universal gas constant , T= Absolute Temperature of the gas We use this equation for the
posted on December 1, 2017 
Chemistry
Assuming complete dissociation of NaI as it is an ionic compound, NaI > Na^+ + I^ x x (moldm^3) and, AgI Ag^+ + I^ y y (moldm^3) y=solubility of AgI So the total [I^]=(x+y) moldm^3 But, Ksp AgI = [Ag^+][I^]=y(x+y) mol^2dm^6 = 1.5*10^16
posted on December 1, 2017 
Physics
Thank you!
posted on August 3, 2017 
Physics
typo: * 1 and 2 are incorrect Actually I was expecting a simpler explanation than what I've found on them already. :)
posted on August 3, 2017 
Physics
*Ty  (M+m)v^2/R + (M+m)g = (M+m)*0 Ty= (M+m)[(v^2/R)  g ]
posted on August 3, 2017 
Math
Did you find any mistakes in my calculations? I thought they were expecting a whole number!
posted on August 3, 2017 
Math
Many thanks to both of you!
posted on August 1, 2017 
Chemistry
At the same temperature one is a liquid and other is a liquid. Being a liquid and having one more step to become vapour,is that a reason for the liquid to have a lower boiling point than the solid?
posted on August 1, 2017 
Math
2x*3y*4z= 24xyz Now substitute the given values to find the value of (24xyz)
posted on August 1, 2017 
Math
(x+1)^2 = x^2 + 2x + 1 So x^2 + 2x + 1 = (7)^2 = 49
posted on August 1, 2017 
Chemistry
How about I2 and Br2 for an example,at room temperature? Br2 is a liquid at room temperature and it's molecular mass is lower than I2(s) and they have same kind of intermolecular forces too.
posted on August 1, 2017 
Chemistry
Never mind and thank you!
posted on August 1, 2017 
Chemistry
I understand and thank you very much!
posted on August 1, 2017 
Chemistry
Thank you!
posted on August 1, 2017 
Chemistry
Question: At the same temperature and under same pressure, one is a liquid and the other is a solid.The molecular mass of the liquid is lower than the solid and they have the same kind of intermolecular forces. Can we simply say the liquid has a lower
posted on July 31, 2017 
Chemistry
I've made a very bad mistake.It should be corrected as one is a solid and the other is liquid. I apologize for the inconveniences made!
posted on July 31, 2017 
Chemistry
I think we have to assume that they are under the same pressure to compare their boiling points. I should've mentioned that!
posted on July 31, 2017 
Chemistry
Yes...Both of them are right. But the answer key has taken that 2nd statement doesn't explain the 1st.That's what I've being thinking about...
posted on July 31, 2017 
Chemistry
At the same temperature one is a liquid and other is a liquid. Being a liquid and having one more step to become vapour,is that a reason for the liquid to have a lower boiling point than the solid?
posted on July 31, 2017 
Chemistry
Or are they both reasons(as they are related)
posted on July 31, 2017 
Chemistry
Thank you!
posted on July 31, 2017 
Chemistry
And one more question: Is the type of bond(covalent!ionic) also important in deciding how easily a compound will hydrolyze?
posted on July 31, 2017 
Chemistry
Thank you!
posted on July 31, 2017 
Math
I've studied calculus. And we're asked to find this for positive integers of c,(c
posted on July 31, 2017 
Math
And what if it's (x+p)^2 + y^2 =p^2 ,instead of (x+p)^2 = p^2 ? How do we eliminate y^2 ?
posted on July 31, 2017 
Math
Thank you!
posted on July 31, 2017 
Math
*so a  (1/a) =(7/12) Multiply both sides from 12a to get, 12(a^2)  12 =7a
posted on July 31, 2017