Answer:
b. 3.66x10²³ atoms of chromium.
Explanation:
First we calculate how many moles are there in 31 grams of chromium, using its molar mass:
- Molar Mass of Chromium = 51 g/mol (This can be found on any periodic table)
- 31 g ÷ 51 g/mol = 0.608 mol
Then we <u>calculate how many atoms are there in 0.608 moles</u>, using <em>Avogadro's number</em>:
- 0.608 mol * 6.023x10²³ atoms/mol = 3.66x10²³ atoms
The correct answer is thus option b. 3.66x10²³ atoms of chromium.
Answer:
Explanation:
Reaction given
6 H⁺ + 2 MnO₄⁻ + 5 (COOH)₂ = 10CO₂ +8H₂O + 2 Mn⁺²
Oxidation number of Mn in MnO₄⁻
= x - 4 x 2 = -1
x = 8 -1
+ 7
Oxidation no of Mn in Mn⁺² = +2
So its oxidation no is decreased from + 7 to + 2 . Hence it is reduced.
<h3>Al + O2 -> Al2O3</h3>
Balance it:
<h3>2Al + 3O2 -> 2Al2O3</h3><h3 />
So you need 2 Al and 3 O2 to make 2 Al2O3 (aluminum oxide).
I'm going to assume you have all the O2 you need.
Since 2 mols of Al is needed to make 2 mols of the product, it's a 1:1 ratio. You get as much aluminum oxide for as much aluminum you burn.
So 12.5 mols if there is not a lack of the O2.
When you heat an atom, some of its electrons are "excited* to higher energy levels. When an electron drops from one level to a lower energy level, it emits a quantum of energy. ... The different mix of energy differences for each atom produces different colours. Each metal gives a characteristic flame emission spectrum.
Answer:
Surfactant. Surfactant, also called surface-active agent, substance such as a detergent that, when added to a liquid, reduces its surface tension, thereby increasing its spreading and wetting properties
Explanation:
