June 2019 Flashcards
1
Q
1.4. Give 2 reasons why the sample must be ionised. (2)
A
(1) (so ions can be) attracted or move to the negative plate
(2) (so ions can be) detected
2
Q
4.4. During each titration, the student rinsed the inside of the conical flask with distilled water. Explain why this rinsing improves the accuracy of each titre. (1)
A
ensures all solutions are mixed
or no solution is lost
or to rinse any droplets from the walls into the reaction mixture
3
Q
7.1. Suggest why magnesium is used in extracting titanium rather than a cheaper metal such as iron. (1)
A
Mg is more reactive than titanium or Fe less reactive than titanium
4
Q
7.3. Give the meaning of the term enthalpy change. (1)
A
heat (energy) change at constant pressure
