This question is about chemical analysis - AQA - GCSE Chemistry - Question 7 - 2015 - Paper 3
Question 7
This question is about chemical analysis.
A student has solutions of three compounds, X, Y and Z.
The student uses tests to identify the ions in the three compound... show full transcript
Worked Solution & Example Answer:This question is about chemical analysis - AQA - GCSE Chemistry - Question 7 - 2015 - Paper 3
Step 1
Identify the two ions present in compound X
96%
114 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The two ions present in compound X are iron(II) ions, represented as Fe²⁺, and sulfate ions, represented as SO₄²⁻.
Step 2
Identify the two ions present in compound Y
99%
104 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The two ions present in compound Y are sodium ions, represented as Na⁺, and iodide ions, represented as I⁻.
Step 3
Identify the two ions present in compound Z
96%
101 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The two ions present in compound Z are iron(III) ions, represented as Fe³⁺, and bromide ions, represented as Br⁻.
Step 4
Compare the advantages and disadvantages of the methods in 7 (b)
98%
120 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
Method 1
Advantages:
Weighing is accurate.
Can confirm the production of a solid precipitate.
Disadvantages:
Not all barium sulfate may be precipitated.
Precipitate may be lost during filtration.
The precipitate may not be dry, affecting mass.
Process is time-consuming and requires energy.
Method 2
Advantages:
More accurate results can be achieved.
Effective for lower concentrations.
Disadvantages:
Accuracy depends on the precise measurement of titrant and endpoints.
