Posts by MAD

Total # Posts: 123

  1. History

    Thank you! It was a really hard time so I understand why I can't find anyone
  2. History

    Hello! I'm going a project on Jim crow laws and I'm having trouble finding people who helped or where an important to it, Anything helps thank you!
  3. Math homework Help Please

    Thank you all so much I was able to get a b and bring up my math grade
  4. Math homework Help Please

    Thank you all so much I was able to get a b and bring up my mafb grade
  5. Math homework Help Please

    I'm not asking for answers I Completely don't understand anything it's taking about. But thank you for those I'll see if they help
  6. Math homework Help Please

    Hii so, I'm on my 5th mental breakdown Today and Its only 9:00 today, and as I know most of you don't care what so ever about what I'm going through and you all have your own problems but I'm honestly horrible at math and this is a big grade for me in it ...
  7. Chemistry

    Which one of these properties is directly proportional to molality and why? A) Electrical conductance B) Heat of solution C) Equilibrium of solution D) Vapour pressure Thanks
  8. Math

    Got a 100 thx!
  9. physic mechanic

    All of the following forces are central force, EXCEPT Semua yang berikut adalah daya berpusat KECUALI A)Coulomb force Daya Coulomb B) Frictional force Daya geseran
  10. physic mechanic

    A particle is pushed horizontally by a constant horizontal force of magnitude F, which starts from the rest at x=0 in the positive ݔ direction. During the movement, it is also acted by the air resistance force that equivalent to bv, where b is the positive coefficient ...
  11. physic

    A particle is pushed horizontally by a constant horizontal force of magnitude F, which starts from the rest at x=0 in the positive ݔ direction. During the movement, it is also acted by the air resistance force that equivalent to bv, where b is the positive coefficient ...
  12. physic

    All of the following forces are central force, EXCEPT A)Coulomb force B) Frictional force C)Gravitational force D)Electrostatic force
  13. physic

    An ant with mass 0.15 g lands on one end of a floating 4.75 g stick. After sitting at rest for a moment, it runs toward the other end with a speed of 3.8 cm/s relative to the river. What is the speed of the stick if it moves in the opposite direction? A) 0.20 cm/s B) 0.16 cm/s...
  14. physic mechanic

    An ant with mass 0.15 g lands on one end of a floating 4.75 g stick. After sitting at rest for a moment, it runs toward the other end with a speed of 3.8 cm/s relative to the river. What is the speed of the stick if it moves in the opposite direction?
  15. Maths

    Mad
  16. Exercise\workout

    I have three questions if you please, can I take protein even if with no any workout? can I take amino acid pills in lower dose to meet some deficiencies ? and, can I take protein along with amino acids for bodybuilding ? Thank you so much
  17. Physics

    A hostess wants to cool her 100g of soup which is currently at 50Celsius, and it's specific heat is 0.8 cal/g celsius, by adding water (specific heat = 1 cal/ g celsius) at a temperature of 5Celsius, how much water should she add, assuming that all the heat from the soup ...
  18. Chemistry

    N = Sp.gr*1000* percent% / eq.wt Prepare 200 ml of 5 N H2SO4 solution from concentrated H2SO4 , if we know that Sp.gr = 1.84 g/ml , percent = 98% , At.wt for (H= 1 , S=32 , O =16 ) Thank you a lot
  19. physics

    What is basically difference between the following : 1)Internal energy and latent heat 2)Internal energy and potential energy I'm really confused , because they're so close in meaning. Thanks
  20. physics

    We have this main law : dPE + dkE + dU = 0 but what about the potential energy (dPE) ?
  21. physics

    But I can't understand that solution , I mean where is it from :(( m*3.3E5= )) ?
  22. physics

    A piece of ice its mass is 2.5 kg and at 0.0 C temperature , it is crawling on the ground with 5.7 m/s , what is the mass of the melted ice , if we know all of the kinetic energy of the ice turn into the internal energy (of the ice ) , that we need 3.3 X 10^5 J to melt 1.0 kg ...
  23. physics

    A person hammered a 0.5 kg something (substance ) with a hammer that its weight is 2.5 kg , with the velocity 65 m /s ,, if one third of the hammer's energy turn into the internal energy to both of the substance and the hammer , then what is the change (increasing ) ...
  24. science

    I want to write a CV , could you help and notice me how to do it ? with respects
  25. english language

    Are there any tips to help to learn and memorizing the phrasal verbs in english ? With Respects
  26. Chemistry

    Yes , that's quite right , I actually meant a hexane that has an ethyl group on an its carbon and a double methyl group on another carbon ? with my best respects
  27. Chemistry

    What is name of this according to the IUPAC: a benzene that has an ethyl group on an its carbon , and a double methyl group on another carbon ? thanks
  28. Math

    Micah is f******* wrong
  29. math

    c
  30. chemistry

    I'm confused , can you do the solution please ?
  31. chemistry

    If we have : H2(g) + 1/2 O2(g) -> H2O(l) dHf= -285.5 Kj N2O5(g) + H2O(l) -> 2HNO3 dHf = -76.6 Kj 1/2 N2 + 3/2 O2 + 1/2 H2 -> HNO3 dHf = - 174.1 Kj then , what is the dHf of 2N2 + 5O2 -> 2N2O5
  32. math

    I can't understand rounding rules of numbers Can you simply explain it ?
  33. CHEMISTRY

    Does a molecular compound in water have hydration or have ionization ?
  34. CHEMISTRY

    How can we prepare or change : 1) change unsaturated to saturated soln? 2) change unsaturated to supersaturated? 3) change saturated to unsaturated ? 4) change saturated to supersaturated ? 5) change supersaturated to unsaturated? 6) change supersaturated to saturated ?
  35. CHEMISTRY

    Which solute will yield a saturated solution ( in the previous two question ) when we dissolve 36 g of each in 25 g of water at 25 oC ? and why ?
  36. CHEMISTRY

    Please
  37. CHEMISTRY

    The solubility of NaNO3 at 40 oC is 102 g/100 g H2O , what is the minimum amount of water to dissolve NaNO3 ( mass of solvent ) ?
  38. CHEMISTRY

    Please
  39. CHEMISTRY

    The solubility of LiCl is 83.5 g/100 g H2O at 20 oC , and is 89.8 g / 100 g H2O at 40 oC , then what is the required mass (in gram ) of LiCl to obtain a saturated solution in 300 g H2O at 25 oC ? please explain thank a lot
  40. CHEMISTRY

    I mean the phase of the gas is going towards being liquid
  41. CHEMISTRY

    Why dissolving gases in the liquids is exothermic while the phase is down ? explain please
  42. CHEMISTRY

    but 22.5/58 = 0.3879 , and 0.3879/0.2 = 1.9 but the answer is another (22) .. I can't get it
  43. CHEMISTRY

    What is the molality of 22.5 g acetone (CH3)2CO , in 200 g water ? ( the answer is 22.0 m , that I think is wrong .. )
  44. CHEMISTRY

    How do the indicators work , by changing color ?
  45. CHEMISTRY

    How can we determine the equivalence point ( or end point ) in the curves in titration ( strong acid/weak base and weak acid/strong base )
  46. CHEMISTRY

    What is difference between equivalence point and end point in the titration ?
  47. CHEMISTRY

    What indicator is better in the following titrations : 1) strong acid/strong base a) methyl red (4.4 - 6.2 ) b) bromophenol blue (6.2 - 7.6 ) 2) strong acid/weak base a) methyl orange (3.1 - 4.4 ) b) bromophenol blue (3.0 - 4.6 ) 3) weak acid/strong a) phenolphthalein (8.0 - ...
  48. CHEMISTRY

    Determine the solvent and solute in the following : a) carat 14 gold b) gaseous drinking ( pepsi for ex.)
  49. CHEMISTRY

    Classify these mixtures to homogeneous and heterogeneous a) orange juice b) tap water ( home water )
  50. CHEMISTRY

    HF + H2O <==> H3O+ + F- By dissolving 0.03 mol HF in 1 L water , seen that [HF] at the equilibrium is 0.027 M , then : 1) If we divide 0.03 mol/ 1 L it would be 0.03 M , why that difference ? 2) How many moles HF in 1 L water is required to reach the equilibrium ?
  51. CHEMISTRY

    Sorry these are two different questions
  52. CHEMISTRY

    CO3^-2 + H3O+ <==> HCO3- + H2O and HPO4^-2 + H2O <==> OH- + H2PO4- During the increasing of the forward reaction , the pH of the solutions would be : 1) increased 2) decreased 3) the same 4) may be increased or decreased My question is that which of them is correct...
  53. CHEMISTRY

    I have trouble how to resist pH in buffer solutions ( in acidic buffer , and in basic buffer ) when we add an acid , and a base ! how the reactions in buffer follow Le chatlier's principle ?
  54. CHEMISTRY

    NH4+ (aq) + OH- (aq) + energy
  55. CHEMISTRY

    Sorry NH3(g) + H2O(l) <==> NH4+ (aq) + OH- (aq) + energy
  56. CHEMISTRY

    NH3(g) + H2O(l) <==> NH4+ (aq) + OH- (aq) a) According to delta H ( Enthalpy ) , which direction the equation will shift ? b) According to Entropy , which direction the equation will shift ? c) Assuming that delta G is positive , then delta S is greater than delta H or ...
  57. CHEMISTRY

    Determine that which directions ( left or right ) shift , of these following equations according to the Entropy 1) HCl (l) <==> HCl (g) 2) C6H12O6 (aq) <==> C6H12O6 (s) 3) 2NH3 (g) <==> N2(g) + 3H2(g) 4) 3C2h$(g) <==> C6H12 (l)
  58. CHEMISTRY

    I think it's so : a) 2C2H2 + 5O2 => 4CO2 + 2H2O + 1301.1kJ b) 0.25mol * 1301.1 kJ = 325.27 kJ energy released c) 1301.1 kJ/1mol = 3900 kJ/ x mol = 2.99mol then X g = mol * molar mass of C2H2 X g = 2.99mol * 26 g/mol = 77.74 g
  59. CHEMISTRY

    If heat of combustion of acetylene C2H2 is -1301.1 kJ/mol then : a) Write balanced thermochemical equation of acetylene combustion b) If 0.25 mol C2H2 reacted according to the previous equation , and what is the emitted energy ? c) how many grams needed to give off 3900 kJ ...
  60. CHEMISTRY

    We have this reaction : HCO3- + OH- => CO3^-2 + H2O Specify the conjugate pairs and , which direction the reaction equilibrium shift ? and How ( as a rule ) ?
  61. CHEMISTRY

    We have : Cl | 1) :B-Cl with two unshared electrons | Cl F | 2) :N-F | F then , if we assume that N and B bind covalently , which of them is acid ? And is that also bronshted- lowry acid ? explain thanks
  62. CHEMISTRY

    Which of the following solutions do they have the maximum osmotic pressure : 1) 0.1 m ( molal conc.) glucose 2) 0.1 m sucrose 3) 0.5 m glucose 4) 0.2 m sucrose and why ?
  63. CHEMISTRY

    Yes , added
  64. CHEMISTRY

    The solubility of KClO3 in 25 oC is 10 g solute per 100 g water if 15 g of KClO3 is embedded in 100 g water in 25 oC , then , what is the amount of KClO3 that can be dissolved ? is the solution unsaturated , saturated , or super saturated ? thank you
  65. CHEMISTRY

    Dye of iodine is prepared by dissolving in ethanol , and 1% ( one percent ) of this solution contains 10 g of solute in 1000 g of solution 1) how many grams of solvent is there in the solution ? 2) how many moles of solute ( I2) is there? 3) what is the molality of 1% of this ...
  66. CHEMISTRY

    Is these two electrodes appropriate to create a good battery ? : Cd => Cd^+2 + 2e- and Fe => Fe^+2 + 2e- Explain
  67. CHEMISTRY

    If a nickel rod embedded in a silver nitrate solution , what do we predict ? explain
  68. CHEMISTRY

    Assuming that this half cell I2 + 2e- + =>2I- as standard electrode and assumed its potential that is 0.00 V : a) what is standard potential of this half cell : Br2 + 2e- + => 2Br- b) what is standard potential of this half cell : Al^+3 + 3e- => Al
  69. CHEMISTRY

    Can a substance made of zinc be coated by nickel , using nickel nitrate solution ? How ?
  70. CHEMISTRY

    In electrolysis , which reaction does occur on the cathode , half oxidation reaction or reduction ?
  71. CHEMISTRY

    Why can't we use water in electrolytic cell during producing aluminium ?
  72. CHEMISTRY

    Why does hydrogen electrode have 0.00 V ? or assumed that has 0.00 V ?
  73. CHEMISTRY

    why dry cells are called dry while they contain water ? in electrochemistry
  74. CHEMISTRY

    Of course it's not a made up problem , it's only a question in our homework Sometimes , I'm just confused on some fine and tiny problems , just it is.. I'm sorry for any mistake and , I'm very grateful
  75. CHEMISTRY

    But the standard Eo of Cr electrode is -0.74
  76. CHEMISTRY

    The standard potential of this cell Sn|Sn^+2 || Cr^+3|Cr is -0.60 V , what is the reductional standard potential of Cr^+3|Cr ? if we know that reduction potential of Sn is Sn^+2 + 2e- <==> Sn : -0.14 V
  77. CHEMISTRY

    What is the function ( or role ) of platinum in electrochemistry in general ? I read a question about platinum in electric potential , and in standard electrode potential ?! thank you a lot
  78. CHEMISTRY

    How many oxidation states Should a substance have at least to undergo Disproportionation reaction ? thanks
  79. CHEMISTRY

    A substance contains an element at its probable maximum oxidation number , does this substance have a maximum chance to be an oxidizing agent or have a minimum chance to be a reducing agent ? thank you
  80. CHEMISTRY

    Not only I don't think so , but I believe it's impossible to balance that , but there is no such reaction and such authentic and valid rxn and equation ! because how possible in chemistry science world that there be an substance has two different oxidation numbers ...
  81. CHEMISTRY

    Ok , I really thank you , but if it's so , can we balance this equation in half reaction method ? : [Cr(N2H4CO)6]4[Cr(CN)6]3 + KMnO4 + H2SO4 ---> K2Cr2O7 + MnSO4 + CO2 + KNO3 +K2SO4 + H2O
  82. CHEMISTRY

    So , on the reactant site you assigned two Chrome in two different oxidation number , but really and basically , is such something possible ? how is it possible one element in a compound on a site of reactant or products has two different oxidation number ??? !!
  83. CHEMISTRY

    I have trouble finding out the oxidation number of each element in the : [Cr(N2h4CO)6]4[Cr(CN)6]3
  84. CHEMISTRY

    Oh ! that was only wrong of typing So it's not wrong with having a "mixed" equation in which you have both molecules and ions ?
  85. CHEMISTRY

    Yes , 3IO3- + 6OH- => 3IO4- + 6e- + 3H2O 2MnO4- + 6e- + 4H2O => 2MnO2 + 8OH- ___________________________________ + 3IO3 + 2MnO4- + H2O => 3IO4- + 2MnO2 + 2OH- and , the final balanced equation is : 3KIO3 + 2KMnO4 H2O => #KIO4 + 2MnO2 + 2OH- so , is it possible that...
  86. CHEMISTRY

    I have these equations in our book , but I've tried a few times to solve it in half reaction method , but I couldn't yet : 1) KMnO4 + KIO3 => MnO2 + KIO4 ( in a basic solution ) 2) MnO4- + Cl- => Mn^+2 + HClO ( in a acidic solution ) I think these are incorrect...
  87. CHEMISTRY

    But ? but in the main reaction , the ClO^- is on the product site not reactant , as you put it on the reactant site , I mean Cl- is oxidized to ClO^- ! On the other hand , I can balance it by myself , but I'm having trouble with KPb(OH)3 , I don't know how to separate ...
  88. CHEMISTRY

    Balance the oxidation reduction equation in half reaction PbO2 + KCl => KClO + KPb(OH)3 thank you a lot
  89. CHEMISTRY

    But there are other sources that gave -1 to H in N2H4 abd +2 to N !
  90. CHEMISTRY

    But it is -1 when bonded with a non metal (N) , and it's also -1 when bonded with a metal ( Ca )
  91. CHEMISTRY

    Why the oxidation number of ( H ) is -1 in 1) N2H4 2) CaH2 while ( N ) is different from ( Ca ) ?
  92. CHEMISTRY

    In half reaction method of the chemical equation balancing , how about those redox reactions that they don't contain any (H) and ( O ) atoms ?
  93. CHEMISTRY

    In relative oxidizing and reducing agents table ; 1) Is Al oxidized by Ni+2 2) Is Cu oxidized by Ag+ 3) Is Pb oxidized by Na+ 4) Is F2 reduced by Cl- 5) Is Br2 reduced by Cl- and if you or no , how it is as a rule to predict any ? thank you
  94. CHEMISTRY

    Assume that the ( S ) ( S ; alphabet ) is the solubility in mol/L of AB2 compound , , then what is the concentration of A and B ? and what is the Ksp of AB2 compound ? thank you a lot
  95. CHEMISTRY

    The Ksp of (hydroxyapatite ) Ca5(PO4)3OH is 6.8 * 10^-37 , and its molar concentration is 2.7 * 10^-5 mol/L ,, if this (hydroxyapatite) reacts with fluoride , then the F- ions replace OH- ions and the product is Ca5(PO4)3F ,, if we know the Ksp of ( fluoroapatite ) is 1.0 * 10...
  96. chemistry

    Why did you use 160 instead of 2.48 g ? and , how do I know #1 and #3 is endothermic and #2 is exothermic ? thank you
  97. CHEMISTRY

    Does it produce precipitate if 1.7 g of AgNO3 and 14.5 g of NaCl solvated in 200 mL water to get a solution in 25 oC ? thank you
  98. CHEMISTRY

    If 2.5 * 10^-2 g of Fe(NO3)3 added to 100mL of 1.0 * 10^-4 M NaOH solution , will it produce precipitate ? thank you
  99. CHEMISTRY

    I'm sorry the underlines are " 1) CO2 2) [ Cu(NH3)4 ]^+2 3) I2 4) 2Cl2 5) Cl2
  100. CHEMISTRY

    Which conditions ( reactant concentration , pressure , and temperature ) elevate high concentration of the underlines in these following equilibrium systems : 1) 2CO + O2 <==> 2CO2 + 167 kJ 2) Cu^+2 + 4NH3 <==> [ Cu(NH3)4 ]^+2 + 24 kJ 3) 2HI + 12.6 kJ <==> H2...
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