Habitat degradation and fragmentation, introduction of exotic species and over harvesting.
These activities disrupt the natural function of a variety of species.
Humans must understand evolution to assess the effect these activities can have on various species and the environment
I just took the test, the answer is A. 305,760 J, good luck.
The weighted average mass of the atoms in a naturally occurring sample of an element is the average atomic mass, also known as atomic weight.
What is atomic mass?
The average mass of an element's atoms expressed in atomic mass units is known as its atomic mass (amu, also known as daltons, D).
The mass of each isotope is multiplied by its abundance to produce the atomic mass, which is a weighted average of all the isotopes of that element.
Any element has a variety of isotopes, thus to take into consideration the fact that each isotope has a different mass, a weighted average mass is used.
A weighted average takes into account the potential that an element's average mass, as calculated from a random sample, will most likely coincide with the average mass of its more common isotopes.
The weighted average masswill therefore be closest to that of the more prevalent isotopes.
To learn more about Atomic mass, refer to the below link:
# SPJ2
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2.28 liters
1.25 liters
0.44 liters
1.50 liters
Answer : The correct option is, (a) 1.05 liters
Solution :
Combined gas law is the combination of Boyle's law, Charles's law and Gay-Lussac's law.
The combined gas equation is,
where,
= initial pressure of gas = 255 kpa
= final pressure of gas = 805 kpa
= initial volume of gas = 2 L
= final volume of gas = ?
= initial temperature of gas =
= final temperature of gas =
Now put all the given values in the above equation, we get the final volume of gas.
Therefore, the final or new volume of gas will be, 1.05 liters
Answer:
approximately 4.8 grams of oxygen gas is formed.
Explanation:
To determine the amount of oxygen (O2) formed when 12.26 grams of potassium chlorate (KClO3) is heated, we need to consider the chemical reaction that occurs during this process. When KClO3 is heated, it decomposes into potassium chloride (KCl) and oxygen gas (O2).
The balanced chemical equation for this reaction is:
2 KClO3(s) → 2 KCl(s) + 3 O2(g)
From the equation, we can see that 2 moles of KClO3 produce 3 moles of O2.
Calculate the molar mass of KClO3:
K: 39.10 g/mol
Cl: 35.45 g/mol
O: 16.00 g/mol
Molar mass of KClO3 = (39.10 + 35.45 + 3 * 16.00) g/mol = 122.55 g/mol
Calculate the number of moles of KClO3 in 12.26 grams:
Moles of KClO3 = (12.26 g) / (122.55 g/mol) = 0.1 moles
Now, we can determine the number of moles of O2 produced using the mole ratio from the balanced equation:
Moles of O2 = (0.1 moles of KClO3) * (3 moles of O2 / 2 moles of KClO3) = 0.15 moles
Finally, convert moles of O2 to grams:
Mass of O2 = (0.15 moles) * (32.00 g/mol for O2) = 4.8 grams
So, when 12.26 grams of KClO3 is heated, approximately 4.8 grams of oxygen gas is formed.
Percentage % yield = 91.8%
Given:
20 g NaCl
45 g AgCl
To find:
% yield=?
The balanced chemical equation will be:
NaCl + AgNO₃ ⇒ AgCl + NaNO₃
First, we need to calculate moles of NaCl.
Then, calculate moles of AgCl from equation:
Mass AgCl(theoretical) :
Now, calculate for percentage yield.
The percentage yield will be 91.8%.
Learn more:
%yield = 91.8
Given
20 g NaCl
45 g AgCl
Required
%yield
Solution
Reaction
NaCl + AgNO₃ ⇒ AgCl + NaNO₃
mol NaCl :
= mass : MW
= 20 g : 58,44 g/mol
= 0.342
mol AgCl from equation :
= 1/1 x mol NaCl
= 1/1 x 0.342
= 0.342
Mass AgCl(theoretical) :
= mol x MW
= 0.342 x 143,32 g/mol
= 49.02 g
%yield = (actual/theoretical) x 100%
%yield = (45/49.02) x 100%
%yield = 91.8