Sodium Thiosulfate and Hydrochloric Acid at Different Concentration of Hydrochloric Acid

Purpose

The purpose of this lab is to compare the reaction between sodium thiosulfate and hydrochloric acid at different concentration of Hydrochloric acid.

Variables

Independent variable : different concentrated M HCl

Dependent Variable : The time in seconds takes for the cross to disappear

Controlled variables

How it will be control

Amount of sodium thiosulfate solution

The amount if sodium thiosulfate must always be the exact 10ml

amount of HCl solution

The amount of different concentrated HCl must always be the same

Same person to observe every trial

We all have different eyesight and in order to get the exact result, we have to keep the same person to observe the trial

Size and darkness of the cross

Size and darkness of the cross should be the same. Otherwise that might change the result

Raw Data

Different concentration of HCl

Time ∓.01 (in second) it takes to disappear the X sign

0.05

Trials

time(in second)

Trial 1

81.1

Trial 2

84.1

Trial 3

75.1

Trial 4

84.1

Trial 5

93.1

Average time

83.5

0.1

Trials

time(in second)

Trial 1

62.1

Trial 2

50.1

Trial 3

63.1

Trial 4

61.1

Trial 5

112.1

Average time

69.5

0.25

Trials

time(in second)

Trial 1

35.1

Trial 2

38.1

Trial