The correct answer is 2.
In oxidation-reduction reactions (or redox reactions), a number of electrons are transferred between two species. During this process, the oxidation number of an atom (or molecule or ion) changes by receiving or losing an electron.
Answer:
The correct answer is A :))
Answer:
A mixture is a physical combination of substances thus it only requires physical processes to separate. However, a compound is chemically combined and can only be separated by chemical processes. Therefore, it is much harder to separate a compound than a mixture.
Answer:
A. 32.6 g/mol
Explanation:
First convert the volume of gas to moles using the ratio 1 mol / 22.4 L at STP.
0.070 L • (1 mol / 22.4 L) = 0.00313 mol
Now divide the grams of gas by the moles of gas:
0.102 g / 0.00313 mol = 32.6 g/mol
Answer:
There are five evidences that tell whether a chemical change has occurred. These are change of color, change of odor, change in temperature or energy, formation of gas and formation of a precipitate.
Explanation:
Chemical Change- This is a type of chemical reaction which occurs when the properties of one or more atoms change and results into a<u> newly formed substance. </u>
Let's have a further discussion of the evidences.
1. Change of Color- Color change is caused by the combination of two or more substance with different molecular structures. A popular example of this is the Statue of the Liberty, which is made of copper plates. Due to the exposure of copper to elements like water, it changed color.
2. Change of Odor- This can be best presented with rotting food. During the rotting process, the food undergoes a chemical reaction. The result is a rotten smell.
3. Change in Temperature or Energy- An example of this is the burning of wood. Its change is considered non-reversible.
4. Formation of Gas- This can be best presented with the cake batter (the one being used to make cakes or pancakes). The batter rises which means it is forming gas. This is caused by the reaction of the baking soda and the acid.
5. Formation of a Precipitate- This occurs when two soluble salts combine and their outcome is an insoluble salt (this is the precipitate).
Take note that if any of these evidences occur, then there's definitely a chemical reaction.
