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3 years ago

Write a sentence that describes the nucleus of an atom

Chemistry

1 answer:

viva [34]3 years ago

3 0

Ok so the nucleus of an atom has all of the positive charge and neutrons concentrated in it.

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Valproic acid, used to treat seizures and bipolar disorder, is composed of C, H, and O. A 0.165-g sample is combusted to produce

sergeinik [125]

Answer:

The empirical formula is = $C_4H_8O$

The formula of Valproic acid = $C_8H_{16}O_2$

Explanation:

Mass of water obtained = 0.166 g

Molar mass of water = 18 g/mol

Moles of $H_2O$ = 0.166 g /18 g/mol = 0.00922 moles

2 moles of hydrogen atoms are present in 1 mole of water. So,

Moles of H = 2 x 0.00922 = 0.01844 moles

Molar mass of H atom = 1.008 g/mol

Mass of H in molecule = 0.01844 x 1.008 = 0.018588 g

Mass of carbon dioxide obtained = 0.403 g

Molar mass of carbon dioxide = 44.01 g/mol

Moles of $CO_2$ = 0.403 g /44.01 g/mol = 0.009157 moles

1 mole of carbon atoms are present in 1 mole of carbon dioxide. So,

Moles of C = 0.009157 moles

Molar mass of C atom = 12.0107 g/mol

Mass of C in molecule = 0.009157 x 12.0107 = 0.11 g

Given that the Valproic acid only contains hydrogen, oxygen and carbon. So,

Mass of O in the sample = Total mass - Mass of C - Mass of H

Mass of the sample = 0.165 g

Mass of O in sample = 0.165 - 0.11 - 0.018588 = 0.036412 g

Molar mass of O = 15.999 g/mol

Moles of O = 0.036412 / 15.999 = 0.002276 moles

Taking the simplest ratio for H, O and C as:

0.01844 : 0.002276 : 0.009157

= 8 : 1 : 4

The empirical formula is = $C_4H_8O$

Molecular formulas is the actual number of atoms of each element in the compound while empirical formulas is the simplest or reduced ratio of the elements in the compound.

Thus,

Molecular mass = n × Empirical mass

Where, n is any positive number from 1, 2, 3...

Mass from the Empirical formula = 4×12 + 8×1 + 16= 72 g/mol

Molar mass = 144 g/mol

So,

Molecular mass = n × Empirical mass

144 = n × 72

⇒ n = 2

The formula of Valproic acid = $C_8H_{16}O_2$

7 0

3 years ago

What is the pH of a 1.00×10-8M KOH solution ?

SVEN [57.7K]

Answer:

the pH of the solution expresses the concentration of hydrogen ion in the solution. By measuring the pH value of a solution helps us to define the acidity or basicity of the solution. If the pH value in the pH scale is greater than 7 then the solution is basic

Explanation:

i hope this helps

7 0

3 years ago

Write the following number in Standard (Numeric) Form. 5.8x10-5

DerKrebs [107]

Answer:

the answer of this question is 0.000058

4 0

3 years ago

Zn(s)+2HCl(aq)->ZnCl2(aq)+H2(g)

kobusy [5.1K]

To answer this we need to assume that at STP 1 mol of a substance is equal to 22.4 L. We use this data for the calculations.
Statement 1
2 mol HCl (1 mol H2 / 2 mol HCl) = 1 mol H2 thus at STP 22.4 L H2
This statement is false.
Statement 2
1 L Zn (1 mol Zn / 22.4 L Zn) (1 mol H2 / 1 mol Zn) (22.4 L H2 / 1 mol H2) = 1L H2
This statement is true.
Statement 3
65.39 g Zn (1 mol Zn / 65.39 g Zn) (1 mol H2 / 1 mol Zn) = 1 mol H2
This statement is true.
Statement 4
1L HCl (1 mol HCl / 22.4 L HCl)(1 mol H2 / 2 mol HCl) = 0.022 mol H2
This statement is false.

7 0

4 years ago

Read 2 more answers

Which characteristic of all living things is the most obvious in the food web?

Wewaii [24]

Answer:

All living organisms share several key characteristics or functions: order, sensitivity or response to the environment, reproduction, growth and development, regulation, homeostasis, and energy processing. When viewed together, these characteristics serve to define life.

Explanation:

hope it helps

5 0

3 years ago