Chemical coagulants can be added to muddy river water to clump suspended solids together so they can be filtered out. In an investigation, different masses of Coagulant X were added to 1000 cm³ samples of river water. The experiment was repeated with Coagulant Y.

The percentages of suspended solids removed are shown in the table below.

Table 1: Effectiveness of Coagulants X and Y

Mass of coagulant added (mg)	Percentage of suspended solids removed (Coagulant X)	Percentage of suspended solids removed (Coagulant Y)
20	32	40
40	45	56
60	58	65
80	72	70
100	81	62
120	82	50
140	76	35

A student concluded:

"The most effective way to purify 1000 cm³ of this river water is to add 60 mg of Coagulant Y."

Use the data in Table 1 to evaluate the student's conclusion.

The percentages of suspended solids removed are shown in the table below.

Table 1: Effectiveness of Coagulants X and Y

Mass of coagulant added (mg)	Percentage of suspended solids removed (Coagulant X)	Percentage of suspended solids removed (Coagulant Y)
20	32	40
40	45	56
60	58	65
80	72	70
100	81	62
120	82	50
140	76	35

A student concluded:

"The most effective way to purify 1000 cm³ of this river water is to add 60 mg of Coagulant Y."

Use the data in Table 1 to evaluate the student's conclusion.

3.2 Methods of separating and purifying substances

Question 26

Table 1: Effectiveness of Coagulants X and Y

Markscheme

3.2 Methods of separating and purifying substances

Question 26

Table 1: Effectiveness of Coagulants X and Y

Markscheme

3.2 Methods of separating and purifying substances

Question 26

Table 1: Effectiveness of Coagulants X and Y

3.2 Methods of separating and purifying substances Questions

3.2 Methods of separating and purifying substances

Question 26

Table 1: Effectiveness of Coagulants X and Y

3.2 Methods of separating and purifying substances Questions