question_answer

  (a)(i)What mass of silver nitrate will react with 5.85 g of sodium chloride to produce 14.35 g of silver chloride and 8.5 g of sodium nitrate? (ii)On what law is the above reaction based and state the law? (b)Calculate the number of molecules in 50 g of . (c)Calculate the mass of 0.5 moles of nitrogen gas, (d) Calculate the number of molecules in 50 g of NaCl. [Atomic mass of Ca = 40 u, C =12 u, 0=16, u, N= 14 u, Na=23u, Cl =35, 5u,

Answer:

   (a) (i)   Mass of reactants = Mass of products x +5.85 = 14.35+8.5 x + 5.85 = 22.85 x = 22.85 -5.85 x =17g Therefore, silver nitrate is 17 g.        (ii)It is based on law of conservation of mass which states that matter can neither be created nor be destroyed in a chemic reaction.                            (b) Molar mass of = 100g 100 g ofmol molecules 50g of molecules (c) Mass of 1 mole of gas = 2 x 14 = 28 g  mass of 0.5 mole of  gas = 28 x 0.5 =14 g    (d) Molar mass of NaCl = 23 + 35.5 = 58.5 g 58.5g of NaCl contains  molecules 50 e or NaCl will contain = 5.147 x1023 molecules