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3 years ago

How many number of atoms does these have?

Chemistry

1 answer:

Olin [163]3 years ago

3 0

Answer:

Explanation:

16. 12

17. 8

18. 9

19. 10

20. 5

21. 15

22.8

23. 24

24. 12

25. 3 i guess( some one comment for 25th pls)

26. 2

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1. A gas having the following composition is burnt under a boiler with 50% excess air.

jeka94

The composition of the stack gas are :

$CH_4$ = 0.8713

$C_3H_8$ = 0.0202

CO = 0.107

<h3 /><h3>What is a mole fraction?</h3>

The ratio of the number of moles of one component of a solution or other mixture to the total number of moles representing all of the components.

Assuming 100 g of the stack gas. Calculate the mass of each species in this sample according to their percentages.

Mass of $CH_4$ : 70% of 100 g = 70 g

Mass of $C_3H_8$ : 15% of 100 g = 15 g

Mass of CO : 15% of 100 g = 15 g

Now calculate the number of moles of each species:

Number of moles of $CH_4$ : $\frac{70 g}{16.04 g/mol}$ = 4.3 mole

Number of moles of $C_3H_8$ : $\frac{15 g}{144.1 g/mol}$ = 0.10 mole

Mass of CO : $\frac{15 g}{28.01 g/mol}$ = 0.53 mole

Now to calculate the mole fraction of each we use the formula:

Mole fraction of $CH_4$ : $\frac{4.3}{4.935}$ = 0.8713

Mole fraction of $C_3H_8$ : $\frac{0.10}{4.935}$ = 0.0202

Mole fraction of CO : $\frac{0.53}{4.935}$ = 0.107

Hence, composition of the stack gas are:

$CH_4$ = 0.8713

$C_3H_8$ = 0.0202

CO = 0.107

Learn more about mole fraction here:

brainly.com/question/13135950

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8 0

2 years ago

Francine makes several measurements of the mass of a metal block. The data set is shown in the table below.

BARSIC [14]

Answer:

Mean

Explanation:

The mean of a series of measurements is calculated when a<em>ll the measurements are added up and then divided by the number of measurements taken</em>, as follows:

Sum of Measurements = 20.73 + 20.76 + 20.68 + 20.75 = 82.92

As<u> there are 4 measurements</u>, the mean is:

Mean = 82.92 / 4 = 20.73

3 0

3 years ago

If an element has an atomic number of 8 and an atomic mass number of 18, would it be an isotope? Why or why not?

hoa [83]

Answer:

It would be an isotope.

Background Information:

Isotopes are typically elements that have a different number of protons than neutrons. The atomic mass is the total number of protons and neutrons. The atomic number is the number of protons.

Explanation:

If the atomic number is the number of protons that means that this particular element has 8 protons. If the atomic mass is the total number of protons and neutrons then we can simply take away the amount of protons from that number, 18 - 8 = 10. If we take protons away from the number of protons and neutrons we are left with the number of neutrons. So there are 10 neutrons. Because there are 8 protons and 10 neutrons, or a different amount of neutrons and protons we know that this particular atom is an isotope.

3 0

3 years ago

Atoms with different numbers of neutrons in their nucleus are:.

bonufazy [111]

Answer: They are referred to as isotopes, which are a form of an element that has different numbers of neutrons in their nucleus.

5 0

3 years ago

What interacted directly with the photographic plates to cause images in Becquerel’s experiment?

Anna [14]

Answer: A. uranium salt

Becquerel made a conclusion that it was the uranium that causes the images found in the photographic plates. Though his theory was disproved during the first time,he continued to develop it. Then, it is through this experiment that Becquerel discovered radioactivity.

7 0

3 years ago