Answer:
By heating the solution
Explanation:
Physical changes and chemical changes are the two types of changes that a substance undergoes. Physical change does not alter the substance's chemical composition, hence, can be easily reversed. There is also no new product formed. This is contrary to the occurrences of a chemical change, which cannot be reversed after a new product has been formed.
A physical change is what occurs when Adrian's teacher dissolves some sugar in a beaker of water to form a sugar solution. This change does not involve any new product formation, hence, can be reversed. The sugar can be derived back from the solution by HEATING THE SOLUTION. The water (solvent) will evaporate and the sugar (solute) will precipitate.
Answer:
B and D could be true
Explanation:
A volume of sodium hydroxide less than expected could occurs for two reasons:
The real concentration of sodium hydroxide was higher than expected or the amount of vinegar added was less than expected:
A. The sodium hydroxide solution had been allowed to stand exposed to the air for a long time prior to the titration. FALSE. A long expose to the air decreases concentration of the NaOH.
B. The volumetric flask used to prepare the diluted vinegar solution was rinsed with water prior to use. TRUE. You add a less amount of vinegar doing you require less amount of NaOH than expected.
C. The burette used to deliver the sodium hydroxide solution was rinsed with water prior to use. FALSE. Thus, you add a less amount of NaOH than expected. To explain the matter, you add more NaOH than expected.
D. The pipette used to deliver the vinegar solution was rinsed with water prior to use. TRUE. Again, you are adding a less amount of Vinegar than expected doing the necessary NaOH during titration less than expected
Water is found in lakes and rivers. Its purpose in nature is to hydrate animals
Hydrogen gas is not abundant in nature, but hydrogen is abundant in water. Hydrogen (bonds) help ice float. Otherwise, freezing lakes would kill animals (it actually doesn't since the ice creates a "coat" above the water").
Ammonia is nitrogen-rich molecules that plant uses to get their nitrogen. It comes from the part of the nitrogen cycle where dead plants and animals are decayed.
Carbon dioxide is what we exhale. Plants "inhale" carbon dioxide and use that for photosynthesis.
Hydrogen sulfide is emitted by volcanoes and by anaerobic (oxygen-less) decay from bacteria.
Have an awesome day! I hope this helps.
The exothermic process is a process or reaction that involves a release of energy from the system to its surroundings in various forms usually through heat, light, electricity or sound. In the four given choices, when melting a copper, you try to immerse the metal in heaping coals of fire. The metal will absorb the thermal energy coming from the coal, thus, once you retrieve the metal back, light will be emitted from it as well as heat.
Therefore, the answer is B. MELTING OF COPPER
