Consider the following four titrations: i. 100.0 ml of 0.10 m hcl titrated with 0.10 m naoh ii. 100.0 ml of 0.10 m naoh titrated with 0.10 m hcl iii. 100.0 ml of 0.10 m ch3nh2 titrated with 0.10 m hcl iv. 100.0 ml of 0.10 m hf titrated with 0.10 m naoh rank the titrations in order of a. increasing volume of titrant added to reach the equiv- alence point. b. increasing ph initially before any titrant has been added. c. increasing ph at the halfway point in equivalence. d. increasing ph at the equivalence point. how would the rankings change if c5h5n replaced ch3nh2 and if hoc6h5 replaced hf?

a chemical change results in a new substance being formed; whereas a physical change will result in a different state of matter

explanation:

the missing options are :

(1) lower boiling point and a lower freezing point(2) lower boiling point and a higher freezing point(3) higher boiling point and a lower freezing point(4) higher boiling point and a higher freezing point

answer : the correct answer is option (3) higher boiling point and a lower freezing point

explanation :

when a non volatile solute is added to a solvent like water, it results in elevation of boiling point.

let us find the increase in boiling point of water when cacl₂ is added to water to make a solution of 1 m

step 1 : find molality of the solution

let us assume we have 1 l of solution.

let us convert this to grams of cacl₂.

molar mass of cacl2 is 111 g/mol

grams of cacl₂ =

mass of solute = 111 g

assuming density of solution same as water which is 1g/ml we have ,

mass of solution = density * volume

mass of solution =

mass of solution = mass of solvent + mass of solute

mass of solute = 1000g - 111g

mass of solute 889 g = 0.889 kg

the molality of the solution can be calculated as

molality = 1.12 m

step 2 : find boiling point elevation.

the elevation in boiling point is calculated as

here δtb = boiling point elevation

i = vant hoff factor which is the number of ions formed by the solute .

cacl₂ dissociates as

it forms 3 ions . therefore,

i = 3

m = molality which is 1.12 m

kb is constant for a given solvent. for water it is 0.512

the boiling point of water increases by 1.7 °c

step 3: find freezing point depression.

when a non volatile solute is added to water, it results in decrease in freezing point.

the formula to find freezing point depression is

kf is constant for water and its value is 1.86

the freezing point of water decreases by 6.2 °c

therefore we can say that, the solution will have a higher boiling point and a lower freezing point