2a, 2b, 2c & 2d – Testing for the Presence or Absence of Substances (LC 2027) (Leaving Cert Biology): Quizzes
📚Quizzes
Practise the questions
13 questions from this quiz
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Practise the questions
13 questions from this quiz
What does qualitative testing determine?
What does qualitative testing determine?
If a substance is present or absent
Which reagent is used to test for starch?
Which reagent is used to test for starch?
Iodine solution
What colour indicates a positive result in the iodine test for starch?
What colour indicates a positive result in the iodine test for starch?
Blue-black
Why does the iodine test work for detecting starch?
Why does the iodine test work for detecting starch?
Iodine fits into starch's spiral structure
Which sugars does Benedict's test detect?
Which sugars does Benedict's test detect?
Reducing sugars
What colour change indicates reducing sugars are present using Benedict's test?
What colour change indicates reducing sugars are present using Benedict's test?
Blue to red
How long must Benedict's test be heated for?
How long must Benedict's test be heated for?
5 minutes
What does a green colour indicate in Benedict's test?
What does a green colour indicate in Benedict's test?
Very little reducing sugar ()
Which reagent tests for protein?
Which reagent tests for protein?
Biuret reagent
What colour indicates protein is present in the Biuret test?
What colour indicates protein is present in the Biuret test?
Purple-violet
Does the Biuret test for protein require heating?
Does the Biuret test for protein require heating?
No, observe without heating
What does the brown paper test detect?
What does the brown paper test detect?
Lipids (fats and oils)
What indicates lipids are present in the brown paper test?
What indicates lipids are present in the brown paper test?
A permanent translucent stain