B) The student then does the titration correctly. He finds that 16.70 cm3 of the dilute sulfuric acid neutralises 25.0 cm3 of sodium hydroxide solution of concentration 0.200 mol/dm3

The equation for the reaction is

2NaOH + H2SO4 → Na2SO4 + 2H2O

iii) Calculate the concentration, in mol/dm3, of the sulfuric acid.

this could be newton#'s law of cooling. the cooling curve is exponential

speed of light in vacuum is 300,000 km/s

speed of light in other mediums is given by the expression v = c/n, where c is the speed of light in vacuum and n is the refractive index of medium.

for the first medium v = 200,000 km/s

  so, refractive index of medium = 300000/200000 = 1.5

    1.5 refractive index is usually for glass. so first medium is glass.

for the second medium v = 250,00 km/s

so, refractive index of medium = 300000/250000 = 1.2

    1.2 refractive index is usually for water. so second medium is water.

for the third medium v = 0 km/s

so, refractive index of medium = 300000/0 = ∞

    ∞ refractive index is usually for opaque mediums. so third medium is opaque medium.

answer///scientific method;