Answer:
d. all of the above are levels of organization
Explanation:
The followings are the levels of the organization in an ecosystem
1. Individual
2. Population
3. Community
4. Ecosystem
5. Biome
6. Biosphere
So as per the given situation, it involved all three levels that are mentioned in the question
hence, the correct option is d.
Therefore the same is to be considered
Answer:
5.2
Explanation:
CH3CO2H (aq) + H2O(l) CH3CO2
-
(aq) + H3O+
(aq)
Initial: 0.64M 1.8M 10-7M
Ka = 1.8 x10-5 = [CH3CO2
-
][ H3O+
] / [CH3CO2H] =
Henderson-Hasselbach equation: pH=pKa + log [A-
]o/[HA]o
Concentrations of [A-
]o,[HA]o are within an order of magnitude
[A-
]o= [CH3CO2
-
] = 1.8M ; /[HA]o = [CH3CO2H] = 0.64M
pH= 4.74 + log [1.8M/0.64M] = 5.2
Answer:
The correct answer is 205.4 g Al
Explanation:
Given the enthalpy of fusion (ΔHf) of aluminum (Al), the amount of heat required to melt the substance is calculated as follows:
heat = ΔHf x moles Al
We have the following data:
ΔHf = 10.7 kJ/mol
heat= 81.4 kJ
So, we calculate the moles of Al we can melt:
moles =heat/ΔHf= 81.4 kJ/(10.7 kJ/mol)= 7.61 moles
The relation between moles and grams of Al is given by the molar mass of Al (27 g/mol). Thus, we multiply the moles of Al by the molar mass to calculate the grams of Al we can melt:
grams = 7.61 moles x 27 g/mol = 205.4 g
The molecular weight of a given compound would simply the
sum of the molar weights of each component.
The molar masses of the elements are:
C = 12 amu
H = 1 amu
N = 14 amu
O = 16 amu
where 1 amu = 1 g / mol
Since there are 6 C, 5 H, 1 N and 2 O, therefore the
total molecular weight is:
molecular weight = 6 (12 amu) + 5 (1 amu) + 1 (14 amu) +
2 (16 amu)
molecular weight = 123 amu
Therefore the molecular weight of nitrobenzene is 123 amu
or which is exactly equivalent to 123 g / mol.
The answer is D. A positively charged sodium Ion and a negatively charged chlorine ion form an ionic bond.
