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3 years ago

Amestec 140 g solutie 9% cu 260 g solutie 12%, cu 60 g apa si x g solutie 4%. Ce c procentuala are noua solutie %?

Chemistry

1 answer:

Levart [38]3 years ago

3 0

Answer:

PLEASE SOMEONE SOLVE THE QUESTION OR I'M GONNA FAIL

Explanation:

Purpose and Theory: A tablet of vitamin C contains the active ingredient called ascorbic acid (HC,H,0.).

Ascorbic acid is an organic acid which is a white power and is soluble in water.

In the following microtitration lab you will be grinding up a vitamin C tablet

, and using a 0.10 g sample of the

vitamin C powder, which will be dissolved in 20-40 mL of water. This solution will be used to determine the

quantity of ascorbic acid in a commercial vitamin C tablet.

Groups

Lab 2

# of Drops 1 or Drops 2 of Drops 3

Hadia

Data & Analysis:

Complete the missing information in the following data table [24]

Trial

Volume of NaOH (drops)

0 05mL drop

(NaOH (O 0050mol/L)

Volume of NaOH (ML)

Average Volume of NaOH (ml)

T I

O 0050

00050

The balanced chemical reaction between ascorbic acid and sodium hydroxide is:

HC,H,O + NaOH NaC,H,Oye H,O,

1. Stoichiometrically calculate the mass (in grams) of ascorbic acid in the powdered sample.

You might be interested in

How is an isotope different from the standard form of a chemical element?

velikii [3]

Answer:

The standard form of a chemical element is the natural mixture of several isotopes of the same element, which is atoms with the same number of protons but different number of neutrons, while an isotope is a particular kind of atom with a definite number of neutrons.

Explanation:

A <em>chemical element</em> is a pure substance formed by atoms with the same atomic number (number of protons). This is because it is the number of protons what identifies an element.

For example: oxygen is a chemical element, so oxygen is formed by only atoms of oxygen, and the atomic number of those atoms is 8, because every oxygen atom has 8 protons.

Nevertheless, some atoms of oxygen, may have different number of neutrons. Isotopes are different kind of atoms of the same element, which only differ in the number of neutrons. So, some atoms of oxygen will have 8 neutrons, other 9 neutrons, and other 10 neutrons (those are the stable isotopes of oxygen).

That difference in neutrons, is generally accepted that, does not modifiy substantially the chemical properties of the element, but the mass number. So, the isotopes with more neutrons wil be heavier, and the isotopes with less neutrons will be lighter.

Mass number = number of protons + number of neutrons.

In general a chemical element is formed by a mixutre of isotopes of the same element.

4 0

3 years ago

Read 2 more answers

A 0.4647-g sample of a compound known to contain only carbon, hydrogen, and oxygen was burned in oxygen to yield 0.01962 mol of

Stella [2.4K]

Answer:

See explanation.

Explanation:

Hello,

In this case, we can show how the empirical formula is found by following the shown below procedure:

1. Compute the moles of carbon in carbon dioxide as the only source of carbon at the products:

$n_C=0.01962molCO_2*\frac{1molC}{1molCO_2} =0.01962molC$

2. Compute the moles of hydrogen in water as the only source of hydrogen at the products:

$n_H=0.01961molH_2O*\frac{2molH}{1molH_2O}=0.03922molH$

3. Compute the mass of oxygen by subtracting the mass of both carbon and hydrogen from the 0.4647-g sample:

$m_O=0.4647g-0.01962molC*\frac{12gC}{1molC}-0.03922molH*\frac{1gH}{1molH} =0.1900gO$

4. Compute the moles of oxygen by using its molar mass:

$n_O=0.1900gO*\frac{1molO}{16gO}=0.01188molO$

5. Divide the moles of carbon, hydrogen and oxygen by the moles of oxygen (smallest one) to find the subscripts in the empirical formula:

$C=\frac{0.01962}{0.01188}=1.65\\ \\H=\frac{0.03922}{0.01188} =3.3\\\\O=\frac{0.01188}{0.01188} =1$

6. Search for the closest whole number (in this case multiply by 2):

$C_3H_6O_2$

Moreover, the empirical formula suggests this compound could be carboxylic acid since it has two oxygen atoms, nevertheless, this is not true since the molar mass is 222.27 g/mol, therefore, we should compute the molar mass of the empirical formula, that is:

$M=12*3+1*6+16*2=74g/mol$

Which is about three times in the molecular formula, for that reason, the actual formula is:

$C_9H_{18}O_6$

It suggest that the compound has a highly oxidizing character due to the presence of oxygen, therefore, we cannot predict the distribution of the functional groups as it could contain, carboxyl, carbonyl, hydroxyl or even peroxi.

Best regards.

6 0

3 years ago

Identify the group of ONLY metalloids.

Alinara [238K]

Answer:

C boron, germanium, arsenic, silicon

5 0

3 years ago

Using the periodic table entry of iron below, match the numbers with what they represent.

evablogger [386]

Answer:

Answers:

1. The number 26 ↔ atomic number

2. The number 56 ↔ mass number

3. The number 4 ↔ the number of orbits

4. The number 30 ↔ number of neutrons.

5. The number 14 ↔ number of electrons in n = 3

6. The number 2 ↔ number of valence electrons.

Explanation:

The same relevant information to deal with the data reported can be found in many periodic tables.

Herewith, I copy the mentioned entry. Please see the image attached.

This is the explanation of the information shown in the entry:

1) Symbol: in the centre of the picture: Fe. It is the symbol of iron.

2) Superscript to the lef of the symbol: 26. It is the atomic number, i.e. the number of protons. Hence, this is the first match:

1. The number 26 ↔ atomic number

3) The number 55.845 below the symbol and name of the element is the atomic mass of the element.

The atomic mass is the avereage mass of the several isotopes of the same element that exist in nature.

The particles that count for the atomic mass are the neutrons and protons, and that is reason of the called mass number, which is the sum of the neutrons and protons of a particular isotope.

An atomic mass of 55.845 means that likely there exist isotopes with mass number 56. This is, with a total number of 56 nucleons (protons and neutrons).

Since, as explained above, Fe has 26 protons, you can calcualte the number of neutrons of the 56 mass number isotope as: n = 56 - 26 = 30 neutrons.

Hence, you can match these:

2. The number 56 ↔ mass number

4. The number 30 ↔ number of neutrons

5. The numbers 2, 8, 14, and 2, that appear in the upper right corner of the image are the number of electrons in the different main energy levels, which is the principal quantum number (n)

They mean:

energy level (n) number of electrons

1 2

2 8

3 14

4 2

Hence you can match this:

5. The number 14 ↔ number of electrons in n = 3

6. The number 2 ↔ number of valence electrons

The valence electrons are the electrons in the last main energy level (here n = 4).

3. The number 4 ↔ the number of orbits

Note: orbits is not a good name for the energy levels, since orbits implies fixed paths around the nucleus and that is an overcome model.

3 0

3 years ago

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How do the elements in each group differ? How are they similar?

bulgar [2K]

Answer:

All the elements in one group have the same number of valence electrons. ... Since elements in a group have the same number of valence electrons, they behave similarly in chemistry. An example would be the alkali metals (excepting hydrogen. Hydrogen is in this group only because it has one valence electron.

Explanation:

5 0

3 years ago

Read 2 more answers