Chemistry
Answer
(a) The four uses of oxygen are:
- Respiration
- Burning
- Industrial uses like welding and cutting metals, removing impurities.
- In medicines like oxygen cylinders for artificial respiration in patients suffering from breathing problems, a mixture of oxygen and nitrous oxide as local anaesthesia.
(b) Oxygen is naturally renewed in air by the process of photosynthesis. Plants use carbon dioxide and water and in presence of sunlight produce glucose and oxygen gas. This oxygen gas is released into air.
Related Questions
What do you observe when the following substances are heated and then tested with moist blue and red litmus paper?
(a) Sulphur
(b) Phosphorus
(c) Calcium
(d) Magnesium
State two differences between: Rusting and Burning.
Fill in the blanks:
(a) …………… is the most abundant inert gas present in air.
(b) Oxides of sulphur and nitrogen combine with rain water to form …………… and …………… which cause …………… .
(c) …………… and …………… are the most common air pollutants.
(d) …………… discovered the oxygen gas.
(e) Oxygen occupies about …………… of air by volume.