Questions asked by KiraTiss

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• Why would you get electrocuted if you went swimming in a pool during an electrical storm? Hint: think about what people put in pools in order to kill bacteria.
  
• Composite function : If #f(x)= 3x+1# and #g(x) = x/(x^2+25)#, how to solve #g(f(x))=0# ?
  
• Function f and g are defined by f(x) = #sqrt((x^2-2x))# and g(x) = 3x +4. The composite function is undefined for x ∈ ]a;b[ . Find the value of a and b?
  
• 5,7% of error in a Hydrated Crystal lab, is it too high?
  
• What amount of atoms, in mol, is present in 128g of sulfur dioxide? Why?
  
• Which sample of fluorine gas, F2, contains the greatest number of fluorine molecules? (multiple choice)
  
• What is the total number of ions present in the formula Na2SO4?
  
• A compound has a molar mass of approximately 56 #g.mol^(-1)#. Which compound might this be? (multiple choice)
  
• Which sample has the greatest mass? (multiple choice)
  
• What would be the empirical formula of a hypothetical compound that contains 60% by mass of element A (#A_(r1) = 10#) and 40% by mass of element B (#A_(r2) =20#)?
  
• When 60g of calcium carbonate is heated, 16.8g of Calcium oxide are formed. What is the percentage yield? (multiple choice)
  
• What volume of ammonia, in #cm^3#, can be prepared by reacting 20 #cm^3# of nitrogen gas with 30 #cm^3# of hydrogen gas?
  
• What amount, in mol, of carbon dioxide will be formed when three moles of methyl propane are combusted completely?
  
• 10 #cm^3# of carbon monoxide and 10 #cm^3# of oxygen are mixed. What will be the total volume of gas present, in #cm^3#, after the reaction?
  
• Which solution contains 0.2 mol of potassium hydroxide, KOH? (multiple choice)
  
• What volume of, in #cm^3#, of 0.200 mol of #dm^(-3)# NaOH is required to neutralize 25.0 #cm^3# of 0.100 mol #dm^3# of H2SO4?
  
• How much energy is released when 14.0 g of carbon monoxide are completely combusted?
  
• (R + RCos (2,57 (20)) = 12), How to solve for R?
  
• Is Fritz Haber consider as a criminal against humanity?
  
• Why concentrated sulphuric acid is used as a catalyst instead of dilute sulphuric acid or a weak acid in esterification?
  
• What is the equilibrium of concentrated nitric acid + sulfuric acid to form nitrobenzene obtained by nitrating benzene?
  
• The second and fifth term of a geometric series are 750 and -6 respectively. Find the common ratio of and the first term of the series?
  
• The velocity of a particule is v = 2t + cos (2t). When t = k the acceleration is 0. Show that k = pi/4?
  
• Why does i2 (iodine) has a oxidation number of 0?
  
• A student wants to investigate the amount of Ascorbic acid in orange juice, with a simple NaOH titration what other substances/compounds of the juice might interfere the results, to which extent?
  
• How do you calculate the amount of ethene (in moles) in 100 cm3?
  
• Let f(x) =x^2+Kx and g(x) = x+K. The graphs of f and g intersect at two distinct points. Find the value of K?
  
• What is the difference between the Endometrium and the uterine lining?
  
• If we bury organic matter deep enough, would it produce fossil fuels?
  
• Why can't we stop methane from leaking?
  
• Is there a membrane that stop liquid water but let Methane gas in?
  
• How do you name the polypeptide Ala-Ser-Gly-Val-Thr-Leu?
  
• Which Chloride should have the greatest covalent character?
  
• Nernst Equation, what is the 2.303 value used in some case of the equation? Mathematically, where does it come from?
  
• A proton moving with a speed of vo = #3.0 * 10^4 m/s# is projected at an angle of 30o above a horizontal plane. If an electric field of 400 N/C is acting down, how long does it take the proton to return to the horizontal plane?
  
• Four charges are brought from infinity and placed at one meter intervals as shown. Determine the electric potential energy of this group?
  
• Two protons, each of charge #+1.60 * 10-19 C#, are #2.00 * 10-5 m# apart. What is the change in the electric potential energy of this pair of charges if they are brought #1.00 * 10-5 m# closer together?
  
• The positive difference between the zeroes of the quadratic expression #x^2 + kx +3# is #sqrt(69)#. What are the possible values of k?
  
• Help with signs, The sum of two numbers is 8, and their product is 9, 75, what are they?
  
• #Area = 210x - 2x^2#, what value of x gives the maximum area?
  
• How to solve #16 + 2^x = 2^(x+1)# without calculator?