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ad-work [718]
3 years ago
7

21 Organs consist of cells and tissues that have been adapted to perform a specific function in living organisms. The stomach is

a muscular organ that is located on the left side of the upper abdomen. The stomach secretes acid and enzymes that help in the digestion of food. In simple terms, the stomach is a digestive sac. Even though the stomach has an important role in food digestion, it cannot perform the process all on its own. It depends on other organs such as the salivary glands, esophagus, liver, and intestines to help complete the process. Each organ has its own specific job, but together they make up an organ system. An organ system is a group of organs that work together to perform one or more functions. Which of the following describes the role of the immune system in the body? A. It gets rid of wastes that the body produces. B. It uses electrical signals to control body functions. C. It uses chemical messages to control body functions. D. It gets rid of pathogens that invade the body.​
Chemistry
1 answer:
Tanya [424]3 years ago
5 0

Answer:

The correct answer is - D.  It gets rid of pathogens that invade the body.​

Explanation:

Like all other organ systems, the immune system is an organ system that involves several special organs that helps in fighting any foreign object or infection that invades our body. This organ system produces specific cells or chemicals to fight or kill the microbes, and unnatural change takes place in the body.

The organs involved in the immune system are lymphocytes or white blood cells, the complement system, antibodies, the lymphatic system the thymus, bone marrow, and the spleen.

All these combinedly helps in fighting, killing the microbes or infections that occur in the body, and correct the physiological changes that occur in the body to get rid of pathogens that invade the body.

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In the formula
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Answer: remove a H2 molecule from the left side of the equation

Explanation:

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If a vessel at this temperature initially contains pure sulfur trioxide and if the partial pressure of sulfur trioxide at equili
inessss [21]

Answer: 2 SO2 (g) + O2 (g) Kp = 7.69 If a vessel at this temperature initially ... and if the partial pressure of sulfur trioxide at equilibrium is 0.100 atm,

Explanation:

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3 years ago
For the following reaction, 4.31 grams of iron are mixed with excess oxygen gas . The reaction yields 5.17 grams of iron(II) oxi
natka813 [3]

<u>Answer:</u> The theoretical yield of iron (II) oxide is 5.53g and percent yield of the reaction is 93.49 %

<u>Explanation:</u>

To calculate the number of moles, we use the equation:

\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}       ....(1)

  • <u>For Iron:</u>

Given mass of iron = 4.31 g

Molar mass of iron = 53.85 g/mol

Putting values in above equation, we get:  

\text{Moles of iron}=\frac{4.31g}{53.85g/mol}=0.0771mol

For the given chemical reaction:

2Fe(s)+O_2(g)\rightarrow 2FeO(s)

By Stoichiometry of the reaction:

2 moles of iron produces 2 moles of iron (ii) oxide.

So, 0.0771 moles of iron will produce = \frac{2}{2}\times 0.0771=0.0771mol of iron (ii) oxide

Now, calculating the theoretical yield of iron (ii) oxide using equation 1, we get:

Moles of of iron (II) oxide = 0.0771 moles

Molar mass of iron (II) oxide = 71.844 g/mol

Putting values in equation 1, we get:  

0.0771mol=\frac{\text{Theoretical yield of iron(ii) oxide}}{71.844g/mol}=5.53g

To calculate the percentage yield of iron (ii) oxide, we use the equation:

\%\text{ yield}=\frac{\text{Experimental yield}}{\text{Theoretical yield}}\times 100

Experimental yield of iron (ii) oxide = 5.17 g

Theoretical yield of iron (ii) oxide = 5.53 g

Putting values in above equation, we get:

\%\text{ yield of iron (ii) oxide}=\frac{5.17g}{5.53g}\times 100\\\\\% \text{yield of iron (ii) oxide}=93.49\%

Hence, the theoretical yield of iron (II) oxide is 5.53g and percent yield of the reaction is 93.49 %

7 0
3 years ago
If the mass of 3 black beans it's 0.7 what's the mass of one bean?
mamaluj [8]

Answer:0.233333333

Explanation: Let me be!

3 0
3 years ago
Read 2 more answers
A 0.0000792 M sample of Compound X in a solvent has an absorbance of 0.341 at 528 nm in a 1.000-cm cuvet. The solvent alone has
natima [27]

Answer:

a) a = 3485 M⁻¹cm⁻¹

b) C = 0,000127 M

Explanation:

Lambert-Beer law says that there is a linear relationship between absorbance and concentration of a chemical substance. The formula is:

A = a×b×C

Where A is absorbance, a is molar absorptivity, b is path length and C is concentration.

a) In the problem Concentration is 0.0000792 M, b is 1,000cm and Absorbance is absorbance of sample-absorbance of blank: 0,341-0,065 = 0,276

Replacing:

0,276 = a×1,000cm×0,0000792M

<em>a = 3485 M⁻¹cm⁻¹</em>

b) As the experiment consist in the same compound in the same solvent, the molar absorptivity will be the same, a = 3485 M⁻¹cm⁻¹, path length will be 1,000cm and absorbance: 0,508-0,065 = 0,443

Replacing:

0,443 = 3485 M⁻¹cm⁻¹×1,000cm×C

<em>C = 0,000127 M </em>

<em></em>

I hope it helps!

8 0
3 years ago
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