All the following "answers" are
for your reference only!
The "best" answers are based on
your actual experimental results!
2. The cotton wool is darkened / has
soot / has carbon particles.
3. Lime water: turn milky
Universal
indicator: turns orange / red
4. It contains carbon dioxide.
5. Nitrogen dioxide.
6. a) Yes.
b) Nitrogen
in the air may react with oxygen in the car cylinder where the temperature is
high to give nitrogen dioxide.
7. (i) dull
red
(ii) bright red
(iii) cherry red
(iv) cherry red
(v) cherry red
a) Cherry red
b) iii, iv, v.
c) yes.
8. Carbon
dioxide, carbon monoxide, sulphur dioxide and nitrogen dioxide.