On easter island what was the primary ecological disaster and why did the people not prevent it?

1 answer:

4 0

Answer:Easter Islanders Didn't Cause Ecological Disaster on Their Island, New Research Finds. New research provides evidence contrary to the widely-held belief that the prehistoric population of Easter Island (Rapa Nui) caused an ecological disaster through rapid deforestation and over-exploitation of natural resources.

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Consider the formation of ammonia in two experiments. (a) to a 1.00-l container at 727°c, 1.30 mol of n2 and 1.65 mol of h2 are

emmasim [6.3K]

When it comes to equilibrium reactions, it useful to do ICE analysis. ICE stands for Initial-Change-Equilibrium. You subtract the initial and change to determine the equilibrium amounts which is the basis for Kc. Kc is the equilibrium constant of concentration which is just the ratio of products to reactant.

Let's do the ICE analysis

2 NH₃ ⇄ N₂ + 3 H₂
I 0 1.3 1.65
C +2x -x -3x
-------------------------------------
E 0.1 ? ?

The variable x is the amount of moles of the substances that reacted. You apply the stoichiometric coefficients by multiplying it by x. Now, we can solve x by:

Equilibrium NH₃ = 0.1 = 0 + 2x
x = 0.05 mol
Therefore,
Equilibrium H₂ = 1.65 - 3(0.05) = 1.5 mol
Equilibrium N₂ = 1..3 - 0.05 = 1.25 mol

For the second part, I am confused with the given reaction because the stoichiometric coefficients do not balance which violates the law of conservation of mass. But you should remember that the Kc values might differ because of the stoichiometric coefficient. For a reaction: aA + bB ⇄ cC, the Kc for this is

$K_{C} = \frac{[ C^{c} ]}{[ A^{a} ][ B^{b} ]}$

Hence, Kc could vary depending on the stoichiometric coefficients of the reaction.

8 0

3 years ago

Mohs hardness strontium

Taya2010 [7]

Answer: 5.5

Explanation: Strontium titanate is both much denser (specific gravity 4.88 for natural, 5.13 for synthetic) and much softer (Mohs hardness 5.5 for synthetic, 6–6.5 for natural) than diamond.

5 0

3 years ago

Three 5-l flasks, fixed with pressure gauges and small valves, each contains 4 g of gas at 273 k. flask a contains h2, flask b c

Varvara68 [4.7K]

First, please check the missing part in your question in the attachment.
a) So first, the Rank of pressure:
according to this formula PV = nRT and when n = m/Mw
PV = m/Mw * R*T
when we have the same mass m and the same V volume so P will proportional with the mole weight M as when the M is smaller the pressure will be greater
when Mw of H2(A) = 2 g / Mw of He (B) = 4 g and Mw of CH4(C) = 16 g
∴ Pressure :
(A) > (B) > (c)

B) The rank of average molecular kinetic energy:
when K = 3/2 KB T
when K is the average kinetic energy per molecule of gas
and KB is Boltzmann's constant
and T is the temperature (K)
So from this equation, we can know that K only depends on T value, and when we have the T constant here for A, B, and C So the rank of K will be like the following:
∴ A = B = C
C) the rank of diffusion rate after the valve is opened:
according to this formula:
R2/R1 = √M1/M2
from this equation, we can see that diffusion is proportional to the reciprocal of the molecular mass M so,
when Mw H2 (A) = 2 g & Mw He(B) = 4 g & CH4 (C) = 16 g
∴ the rank of diffusion:
A > B > C

D) The rank of the Total kinetic energy of the molecules:
when we have the Mw different so it will make the no.of molecules differs as when the Mw is low the no.of molecules will be hight, and when the average molecular kinetic energy equals. so the total kinetic energy will depend on no. of molecules
∵ Mw A < Mw B < Mw C
∴no .of molecules of A > B >C
∴ the rank of total kinetic energy is:
A > B > C

e) the rank of density:

when ρ = m/ v
and m is the mass & v is the volume and we have both is the same for A, B, and C
so the density also will be the same, ∴ the rank of the density is:
A = B = C

F) the rank of the collision frequency:
as the no.of molecules increase the collision frequency increase and depend also on the velocity and it's here the same.
∴ Collision frequency will only depend on the no.of molecules
we have no.of molecules of A > B > C as Mw A B > C

7 0

3 years ago

What is isotope the percentage of the solid components of soil

zubka84 [21]

Answer:

an isotope consists of two or more forms of the same elements that contains equal number of protons but different number of neutrons in their nuclei but differ in relative atomic mass but not in chemical properties

The percentage of soil components of the soil is: inorganic components

-soil particles

-mineral elements = 45%

-water or moisture= 25%

- air= 25%

organic components

-humus or decayed organic matter= 5%

-living organisms

4 0

3 years ago

A 9-ounce of glass contains 72 milligrams of vitamin

sleet_krkn [62]

Answer: 7.2 ounces

Explanation:

1) Data:

- glass size: 9-ounce

- content of vitamin C: 72 milligrams


- glasssize: x

- content of vitamin C: 60 milligrams


2) Proportion


9 ounces / 75 mg = x / 60 mg


3) Solution:


9 ounces × 60 mg = 75 mg × x


⇒ x = 9 ounces × 60 mg / 75 mg = 7.2 ounces

7 0

4 years ago