Questions asked by Marta O.

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• Can you write the equation for the oxidation and reduction half-reactions for the redox reactions below, and then balance the reaction equations? As2O3+HNO3--> As2O5+NO2+H2O
  
• What is the solution? If sin x=8/17, sin y= 15/17, and 0<x< π/2, 0<y<π/2; then x+y= π/2. Prove it!
  
• How do you verify? #(cos2x)/ (1+sin2x) =(1-tanx)/(1+tanx)#
  
• How to solve this inequality #|sin2x|>sqrt3/2 # ?
  
• What kind of experiments can I try that are connected with plant physiology?
  
• How to calculate the volume of hydrogen which generates from 2g of sodium?
  
• When we hang on the spring a weight mass 3 kg( 6.6 lbs), its length is 83.9 cm (33.03 in). And with weight of mass 9 kg(19.8 lbs), springs length is 142.7 cm(56.18 in). What is the springs constant? At the same spring flickers weight of 5 kg(11.2 lbs.) ?
  
• 10 g of Cu, 10 g of O2 react. Which is the limiting reactant? What amount of reactant remains in excess? Calculate the number of particles of reactant in excess. What is the mass of the produced product?
  
• Current strength of 0.2A carry out electrolysis of aqueous potassium chloride for 10 minutes.The volume of solution is 125 ml and it is assumed that during the electrolysis does not change.What is the plural concentration of OH- ions at the end of the...?
  
• Calculate the volume of chlorine that is required to convert 1 kg of iron in ferric 3 chloride at standard conditions?
  
• Calculate the volume of chlorine at 120 kPa and 20 °C that is required to convert 7 kg iron to ferric chloride?
  
• Given the circle #(x-4)^2 + (y+6)^2 =4#, determine all values of the real number c if the direction #3x+2y=c# is the tangent of the circle?
  
• How long is the human DNA?
  
• What is the rate of replication of the DNA, comparing to the domino effect?
  
• Burning then sample of an organic compound with the weight of 0.00480 g it is afforded: 0.00703 g of the CO2 and 0.00283 g of the H2O, Determine the empirical formula of the compound which consists of hydrogen, carbon and oxygen?
  
• Determine the molecular formula of a hydrocarbon if the combustion of 5.3 mg obtained 16.6 mg #"CO"_2#. The density of the gas at standard conditions is #"2.504 g/dm"^3#. What is the molar mass of the gas and its molecular and empirical formula?
  
• How many different gametes has a human being?
  
• How goes the redox reaction of burning methane?
  
• What are the concentrations (ω) of carbon, hydrogen and chlorine in chlorineciklohexane?
  
• How to solve this?
  
• How can I solve this?
  
• How to solve second grade inequality with modulo? The result is -3 and 3, and I get the result 3 and -1
  
• 1.50 kg of ice (-15ºC) is brought to a water (+37ºC). Specific thermal capacity of ice is 2.09 J/K g and water 4.18 J/K g. Molecular ice melting heat is 6.02 kJ/mol. How to calculate the total amount of heat consumed for the specified change?
  
• Diamond structure: Each carbon atom is tetrahedral surrounded with 4 carbon atoms. How do I get to the number of carbon atoms in the elemental steel?
  
• What does the reaction between benzene and ethanol produce?
  
• How can I balance this redox reaction?
  
• How to calculate the pH of the solution if 150 mL of hydrochloric acid is consumed to complete the raction with the magnesium, with a total concentration of 0.45 #"mol / dm"^-3#?
  
• Why is there a minus in the answer? The answer should be -102 kJ/mol, but I get 102 kJ/mol
  
• Distances from Zagreb to Vienna is 400 km. At the same time, the first train goes from Zagreb with the speed of 100 km/h and the second train from Vienna goes 120 km/h. How to calculate the meeting spot graphicaly?
  
• How to sove this "percentage" problem?
  
• How to calculate the density of this crystal?
  
• How to Calculate the Number of Tin Atoms in a Can?
  
• How to calculate the pH of this solution? 0.002 mol of solid calcium hydroxide is added in 250 mL solution of hydrochloric acid with the concentration of 0.004 mol / L.
  
• How to calculate the number of protons in 1.00 g of #C_60#?
  
• One of the chlorophylls, chlorophyll a, has four nitrogen atoms in a molecule, and the mass fraction of nitrogen is 6.27%. What is the relative molar mass of chlorophyll a?
  
• Fresh cranberry contains 88% of water and dried 5% of water. How much is the mass of fresh cranberries from which can we get 5 kg of dried cranberries?