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3 years ago

Science What part of all organisms Is involved in the exchanging of gases

2 answers:

7 0

Gas exchange occurs in microscopic dead-end air-filled sacs called alveoli, where a very thin membrane (called the blood-air barrier) separates the blood in the alveolar capillaries (in the walls of the alveoli) from the alveolar air in the sacs.

Anuta_ua [19.1K]3 years ago

3 0

Answer:

Explanation:

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An acid-base reaction will always produce water and which one of the

Nonamiya [84]

Answer: Option D) Salt

Explanation:

An example of acid-base reaction is

HCl(aq) + NaOH(aq) → NaCl(aq) + H2O(l)

Acid + base → Salt + Water.

Here, water H2O and salt, NaCl are produced.

Usually, the acid, aqeous HCl reacts completely with an appropriate amount of the base, aqueous NaOH to produce salt, aqueous NaCl and water, liquid H2O only, in a process also known as neutralization reaction

8 0

4 years ago

Calculate the concentration in mol L^-1 of ammonium ions in a solution prepared by mixing 360 mL of 0.250 mol L^-1 ammonium sulf

Mnenie [13.5K]

In order to determine the concentration of ammonium ions in the solution prepared by mixing solutions of ammonium sulfate, (NH4)2SO4, and ammonium nitrate, first calculate the amount of ammonium ions for each solution.

For ammonium sulfate sol'n: 0.360 L x 0.250 mol(NH4)2SO4/ L x 2 mol NH4+ /1 mol(NH4)2SO4 = 0.18 mol NH4+
For ammonium nitrate sol'n: 0.675 x 1.2 mol NH4NO3/L x 1 mol NH4+ /1 molNH4NO3 = 0.81 mol NH4+

Thus, the amount of NH4+ ions is (0.18 + 0.81) mol or 0.99 mol NH4+. To get the concentration, multiply this to the volume of solution which is assumed to be additive, such that:

M NH4+ in sol’n = 0.99 mol NH4+/1.035 L = 0.9565 mol NH4+/ L sol’n

8 0

3 years ago

A mixture of water and graphite is heated to 600 K in a 1 L container. When the system comes to equilibrium it contains 0.17 mol

Kryger [21]

Answer:

0.44 moles

Explanation:

Given that :

A mixture of water and graphite is heated to 600 K in a 1 L container. When the system comes to equilibrium it contains 0.17 mol of H2, 0.17 mol of CO, 0.74 mol of H2O, and some graphite.

The equilibrium constant $K_c= \dfrac{[CO][H_2]}{[H_2O]}$

The equilibrium constant $K_c= \dfrac{(0.17 )(0.17)}{0.74}$

The equilibrium constant $K_c= 0.03905$

Some O2 is added to the system and a spark is applied so that the H2 reacts completely with the O2.

The equation for the reaction is :

$H_2 + \dfrac{1}{2}O_2 \to H_2O \\ \\ 0.17 \ \ \ \ \ \ \ \ \ \to0.17$

Total mole of water now = 0.74+0.17

Total mole of water now = 0.91 moles

Again:

$K_c= \dfrac{[CO][H_2]}{[H_2O]}$

$0.03905 = \dfrac{[0.17+x][x]}{[0.91 -x]}$

0.03905(0.91 -x) = (0.17 +x)(x)

0.0355355 - 0.03905x = 0.17x + x²

0.0355355 +0.13095 x -x²

x² - 0.13095 x - 0.0355355 = 0

By using quadratic formula

x = 0.265 or x = -0.134

Going by the value with the positive integer; x = 0.265 moles

Total moles of CO in the flask when the system returns to equilibrium is :

= 0.17 + x

= 0.17 + 0.265

= 0.435 moles

=0.44 moles (to two significant figures)

3 0

4 years ago

For 13 points plz. Plz

Ludmilka [50]

Answer:

Individual versus nature

Explanation:

The type of conflict is individual versus nature because the cat faced many problems in nature such as facing the mouse, grass, people, etc. These are all considered as nature

PLEASE DO MARK ME AS BRAINLIEST IF MY ANSWER IS HELPFUL ;) 

4 0

3 years ago

What type of grass is poisioness

ikadub [295]

Answer: Tall fescue can be harmful to grazing cattle and horses because the grass can become tough and infected with endophytes, causing poor grazing. Switchgrass and tall fescue are less likely to be poisonous to dogs, cats or humans than to horses or cattle, but eating either of them might cause stomach upset.

Explanation:

5 0

3 years ago

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