Which of the following processes would you classify as chemical reactions?
A: The burning of paper
B: The formation of rust on iron
C: The boiling of water
D: The preparation of sugar syrup by adding sugar to hot water
E: The manufacture of salt by evaporation of sea water
A: The burning of paper
B: The formation of rust on iron
C: The boiling of water
D: The preparation of sugar syrup by adding sugar to hot water
E: The manufacture of salt by evaporation of sea water
A,B
举一反三
- This main idea of the country A: the formation of sugar B: the role of water in a growing plant C: the functions of carbon dioxide and water D: the synthesis of water with carbon dioxide
- Which statement of the following is false according to the passage A: The boiling point of water on a mountain three kilometers high is only 90 Celsius. B: It would take you longer to cook potatoes in boiling water on the mountain than it would at sea level. C: When the temperature of a liquid is raised enough, the liquid boils. D: The boiling point of water on a mountain six kilometers high is 95 Celsius.
- How many ships are there in the sea A: With sugar in it. B: With milk in it C: With water in it.
- In order to make good lemonade with one cup of lemon juice, we should add to it __________. A: two spoons of sugar and two quarts of water B: one cup of sugar and two quarts of water C: one cup of sugar and one quart of water D: one spoon of sugar and one quart of water
- (The specific heat of water is 4190 J/Kg·K) You have a 200 g<br/>cup of water at 100 °C, too hot to drink. If you cool it by<br/>adding 100 gm of water at 10 °C, the water is cooled to (). A: 70°C B: 30°C C: 50°C D: 60°C
内容
- 0
Evaporation from sea water is about 5% less than from fresh water, ______(当其他所有条件都相同时).
- 1
The major osmoregulatory problems of saltwater fishes are ( ). A: water gain and salt loss B: water loss and salt gain C: water gain and salt gain D: water loss and salt loss E: nonexistent because freshwater fishes are isosmotic to their environment
- 2
选择最佳答案：开水--- A: boiling water B: boil water
- 3
boiling water
- 4
Water of body are from（ ）。 A: the liquids we drink B: evaporation of water from the skin C: the foods we eat D: respiration of water vapor from the lungs E: recycled water in our bodies