You have to calculate the oxidation estates of the atoms in each compound.
I will start with K2Cr2O7 because I believe that Cr is the best candidate to reduce its oxidation number in 3 units.
In K2Cr2O7:
- K has oxidation state of 1+, then K2 has a charge of 2* (1+) = 2+.
- O has oxidation state of 2*, then O7 has a charge of 7* (2-) = 14-.
That makes that Cr2 has charge of 14 - 2 = +12, so each Cr has +12/2 = +6 oxidation state.
In Cr2O3:
- O has oxidation state of 2-, then O3 has charge 3 * (2-) = - 6
- Then, Cr2 has charge 6+, and each Cr has charge 6+ / 2 = 3+.
So, we have seen that Cr reduced its oxidation state in 3 units, from 6+ to 3+.
Answer: Cr has a change in oxidation number of - 3.
Answer:
Opaque → a.no light travels through the material; all light is reflected or absorbed
Translucent → b.some light travels through the material and the image cannot be seen clearly
Transparent → c.all light travels through the material and the image can be seen clearly
Explanation:
Hope this helps :)
Answer:
The halogens, nitrogen and sulphur are covalently bonded to the organic compounds. In order to detect them, the elements need to be converted into their ionic forms. This is done by fusing the organic compound with sodium metal. ... The extract is called sodium fusion extract or Lassaigne's extract.
A decomposition reaction<span> is a type of chemical </span>reaction<span> in which a single compound breaks down into two or more elements or new compounds. These </span>reactions<span> often involve an energy source such as heat, light, or electricity that breaks apart the bonds of compounds. so it is a decomposition reaction because the silver chloride breaks down into silver and chlorine</span>
The number of moles of ethanol the chemist will use in the experiment involving 30g of ethanol is 0.65moles.
<h3>How to calculate number of moles?</h3>
The number of moles of a substance can be calculated by dividing the mass of the substance by its molar mass. That is;
no. of moles = mass ÷ molar mass
According to this question, a chemist will use a sample of 30 g of ethanol (CH3CH2OH) in an experiment. The number of moles can be calculated as follows:
Molar mass of ethanol = 12(2) + 1(5) + 17 = 46g/mol
no of moles = 30g ÷ 46g/mol
no. of moles = 0.65moles
Therefore, the number of moles of ethanol the chemist will use in the experiment involving 30g of ethanol is 0.65moles.
Learn more about moles at: brainly.com/question/1458253