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2 years ago

Help 4 me???? ples????

Chemistry

2 answers:

Ainat [17]2 years ago

4 0

I think it’s the second one

frutty [35]2 years ago

3 0

Answer:

its the first one.

Explanation:

If sodium loses an electron, it now has 11 protons, 11 neutrons, and only 10 electrons, leaving it with an overall charge of +1

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A gaseous mixture composed of 20% CH4, 30% C2H4, 35% C2H2, and 15% C2H20. What is the average molecular weight of the mixture? a

Semenov [28]

Answer: The correct answer is Option d.

Explanation:

We are given:

Mass percentage of $CH_4$ = 20 %

So, mole fraction of $CH_4$ = 0.2

Mass percentage of $C_2H_4$ = 30 %

So, mole fraction of $C_2H_4$ = 0.3

Mass percentage of $C_2H_2$ = 35 %

So, mole fraction of $C_2H_2$ = 0.35

Mass percentage of $C_2H_2O$ = 15 %

So, mole fraction of $C_2H_2O$ = 0.15

We know that:

Molar mass of $CH_4$ = 16 g/mol

Molar mass of $C_2H_4$ = 28 g/mol

Molar mass of $C_2H_2$ = 26 g/mol

Molar mass of $C_2H_2O$ = 48 g/mol

To calculate the average molecular mass of the mixture, we use the equation:

$\text{Average molecular weight of mixture}=\frac{_{i=1}^n\sum{\chi_im_i}}{n_i}$

where,

$\chi_i$ = mole fractions of i-th species

$m_i$ = molar masses of i-th species

$n_i$ = number of observations

Putting values in above equation:

$\text{Average molecular weight}=\frac{(\chi_{CH_4}\times M_{CH_4})+(\chi_{C_2H_4}\times M_{C_2H_4})+(\chi_{C_2H_2}\times M_{C_2H_2})+(\chi_{C_2H_2O}\times M_{C_2H_2O})}{4}$

$\text{Average molecular weight of mixture}=\frac{(0.20\times 16)+(0.30\times 28)+(0.35\times 26)+(0.15\times 42)}{4}\\\\\text{Average molecular weight of mixture}=6.75$

Hence, the correct answer is Option d.

3 0

3 years ago

Use the periodic table to determine the electron configuration for Ca and Pm in noble-gas notation Ca: [Ar]4s2 [Ar]4s1 [Ar]3s2 [

sveta [45]

Answer:

1) Ca: [Ar]4s²
2) Pm: [Xe]6s²4f⁵

Explanation:

1) Ca:

Its atomic number is 20. So it has 20 protons and 20 electrons.

Since it is in the row (period) 4 the noble gas before it is Ar, and the electron configuration is that of Argon whose atomic number is 18.

So, you have two more electrons (20 - 18 = 2) to distribute.

Those two electrons go the the orbital 4s.

Finally, the electron configuration is [Ar] 4s².

2) Pm

The atomic number of Pm is 61, so it has 61 protons and 61 electrons.

Pm is in the row (period) 6. So, the noble gas before Pm is Xe.

The atomic number of Xe is 54.

Therefore, you have to distribute 61 - 54 = 7 electrons on the orbitals 6s and 4f.

The resultant distribution for Pm is: [Xe]6s² 4f⁵.

5 0

2 years ago

Read 2 more answers

What is the negatively charged sub-atomic particle of an atom?

vitfil [10]

C electron. Electrons have a negative charge!

7 0

3 years ago

Read 2 more answers

Draw the structure of the organic product(s) of the grignard reaction between phosgene (clcocl) and excess phenylmagnesium bromi

Jobisdone [24]

Phosgene on reacting with phenylmagnesium bromide generates benzoyl chloride.

Since, phenylmagnesium bromide is added in excess. It would further react with benzoyl chloride to form benzophenone.

Benzophenone on further reacting with phenylmagnesium bromide, and aqueous treatment, gives triphenylmethanol.

Entire reaction pathways is shown below:

8 0

3 years ago

Read 2 more answers

Describe the experimental basis for believing that the nucleus occupies a very small fraction of the volume of the atom.

svetlana [45]

Explanation:

Rutherford conducted an experiment in which he took a thin gold particle film on which he passes alpha- particles. He noticed that:

Most of the alpha particles get through the film and can be detected by the detector.
Around small portion of the alpha particle deflected at small angles.
A very very few alpha particle (approximately 1 out of 1 million alpha particles) just retraced their path which means come back from the center.

He concluded that:

Most of the space of the atom is empty and in the center of the atom , there is solid mass which is the cause of the alpha particles to come back. He gave the term nucleus to this solid mass.

4 0

3 years ago