Answer:
Explanation:
Oxygen is one of the most abundant elements on this planet. Our atmosphere is 21% free elemental oxygen. Oxygen is also extensively combined in compounds in the earths crust, such as water (89%) and in mineral oxides. Even the human body is 65% oxygen by mass.
Free elemental oxygen occurs naturally as a gas in the form of diatomic molecules, O2 (g). Oxygen exhibits many unique physical and chemical properties. For example, oxygen is a colorless and odorless gas, with a density greater than that of air, and a very low solubility in water. In fact, the latter two properties greatly facilitate the collection of oxygen in this lab. Among the unique chemical properties of oxygen are its ability to support respiration in plants and animals, and its ability to support combustion.
In this lab, oxygen will be generated as a product of the decomposition of hydrogen peroxide. A catalyst is used to speed up the rate of the decomposition reaction, which would otherwise be too slow to use as a source of oxygen. The catalyst does not get consumed by the reaction, and can be collected for re-use once the reaction is complete. The particular catalyst used in this lab is manganese(IV) oxide.
Answer:
d. Enzymes are broken down by the reactions they catalyze.
Explanation:
Answer: 
is the limiting reagent
Explanation:
To calculate the moles :
The balanced chemical reaction is :
According to stoichiometry :
1 moles of require = 2 moles of 
Thus 0.625 moles of will require=
of
Thus is the limiting reagent as it limits the formation of product and is the excess reagent as it is present more than the required amount.
Answer:
Explanation:
The amine functional group is obtained by subsititution of one or more hydrogen atoms in the ammonia compound.
Ammonia is NH₃.
Then,
- by substituting one hydrogen you obtain R - NH₂.
- by substituting two hydrogens you obtain R' - NH - R''
- by subsituting the three hydrogens you obtain:
R'''
|
R' - N - R''
In this case, the three subsitutuents are silyl groups. The silyl group is derived form silane and is SiH₃. So, the tcompound <em>trisilylamine</em> is:
SiH₃
|
SiH₃ - N - SiH₃
Thus, you can count 3 hydrogen atoms for every silylgroup for a total of <u><em>9 hydrogen atoms in each molecule of trisilylamine.</em></u>
