how is the caloric value of a food sample determined?

Answer:

We have the final answer as

Explanation:

The volume of a substance when given the density and mass can be found by using the formula

[tex]volume = \frac{mass}{density} \\[/tex]

From the question

mass = 6 g

density = 6 g/cm³

It's volume is

[tex]volume = \frac{6}{6} = 1 \\ [/tex]

We have the final answer as

Hope this helps you

Answer:

molar mass: 151.165

Explanation:

mass of Carbon is 12.011 amu

mass of Hydrogen is 1.008

mass of Nitrogen is 14.007

mass of Oxygen is 15.999

you make the calculations like this...

[tex](12.011 \times 8) + (1.008 \times 9) + (14.007) + (15.999 \times 2) = 151.165amu[/tex]

Answer:

true

Explanation:

what is the answer? please

Answer:

Empirical formula: C₂SH₄

Molecular formula: C₄S₂H₈

Explanation:

The empirical formula is the simplest whole ratio of atoms presents in an element.

The compound contains C, S and H, its empirical formula is CₐSₓHₙ. We need to determine a, x and n solving for the moles of each element, thus:

Moles H₂O - moles H-:

PV/RT = n

At STP, P is 1atm, and T is 273.15K:

1atm*44.8L / 0.082atmL/molK*273.15K

moles H₂O = 2 moles water = 4 moles of H

Because 1 moles of water contains 2 moles of H

Moles CO₂ = moles C:

88.0g CO₂ * (1mol / 44g) = 2 moles CO₂ = 2 moles C

The mass of carbon is:

2 moles * (12g/mol) = 24g

Mass of hydrogen:

4 moles * (1g/mol) = 4g

The mass of S is:

60.04g - 24g - 4g = 32.04g = 1 mole of S

Empirical formula is:

Now, the moles of the compound in the final experiment are:

PV / RT = n

2.33atm*3.57L / 0.082atmL/molK*298.15K = 0.34 moles

-25°C = 298.15K. In gas laws you must use absolute temperature given in Kelvin-

These moles are in 35.0g. The molar mass of the compound is:

35.0g / 0.34 moles = 102.9g/mol

As the empirical formula is C₂SH₄ and weighs 60g/mol. Twice the empirical formula are the molecular formula:

The Molecular formula of the compound: C₄S₂H₈

[tex]n=\frac{PV}{RT}[/tex]

At STP, P is 1atm, and T is 273.15K:

[tex]n= \frac{1atm*44.8L}{0.082atmL/molK*273.15K}[/tex]

Moles H₂O = 2 moles water = 4 moles of H

As, 1 moles of water contains 2 moles of H

88.0g CO₂ * (1mol / 44g) = 2 moles CO₂ = 2 moles C

We know,

[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex]

Mass of carbon is: [tex]2 moles * (12g/mol) = 24g[/tex]

Mass of hydrogen is: [tex]4 moles * (1g/mol) = 4g[/tex]

Mass of sulphur is: [tex]60.04g - 24g - 4g = 32.04g[/tex] = 1 mole of S

The derived Empirical formula will be: C₂SH₄

Now, the moles of the compound in the final experiment are:

[tex]n= \frac{PV}{RT}\\\\n=\frac{2.33atm*3.57L}{0.082atmL/molK*298.15K}\\\\ n= 0.34 moles[/tex]

These moles are in 35.0g. The molar mass of the compound is: [tex]\frac{35.0g}{0.34 moles} =102.9g/mol[/tex]

As the empirical formula is C₂SH₄ and weighs 60g/mol.

The empirical formula is two times the molecular formula: C₄S₂H₈

Find more information about "Molecular formula" here:

brainly.com/question/1603500

Answer:

kinetic

Explanation:

Answer:

the number of electrons is 13 and neutrons is 14

Answer:

Ensure that the glassware is designed for heating

Check that there are no cracks in the glassware

Inspect the hot plate for frayed cords

Explanation:

All except measuring the height and width of the glassware could cause hazards within the lab.

Answer:

Ask a question?

Explanation:

look at the scientific method uwu

Answer:

B. what happens when iron rusts in the presence of water

Explanation:

Chemistry is a branch of science involving the composition and changes of matter. In other words, a chemist, who is a trained specialist in the science of chemistry, seeks to answer questions related to properties of matter.

In this question, a chemist is most likely to study "what happens when iron rusts in the presence of water" because it involves a change in the chemical properties of a substance (iron) i.e. a chemical change. However, what happens when ice melts to liquid water is a physical change.

Answer: Depending on the arrangement of outer atoms, this molecule could be polar or nonpolar.

Explanation:

Polarity is when the electric charge that is leading to a molecule is being separated.

The polarity of SCL4F2 can either be polar or non polar and this depends on the arrangement of outer atoms. It is the arrangements of these outer atoms that'll help in the determination of its polarity.

The molecule SCl4F2 could be polar or nonpolar depending on the arrangement of outer atoms.

The molecule SCl4F2 could have different arrangements of outer atoms. That means that there are two possible arrangements of the molecule. Depending on which arrangement the outer Cl and F atoms have, the molecule cold be polar or nonpolar.

In the arrangement of SCl4F2  which could be polar is the one in which the dipoles in the molecule do not cancel out. In the other arrangement, the dipoles cancel out and the molecule is nonpolar.

Learn more: https://brainly.com/question/1340582

Answer: Cathode rays are made up of negatively charged particles.

Atoms contain negatively charged particles.

Answer:

Addiction

Explanation:

The shape and function of a protein are primarily determined by its three-dimensional structure, which is a result of its primary, secondary, tertiary, and quaternary structures.

Primary Structure: The primary structure of a protein is the linear sequence of amino acids that make up the polypeptide chain. The sequence is dictated by the genetic information encoded in the DNA of the gene that corresponds to the protein. Each amino acid in the sequence is represented by a specific codon in the DNA, and this sequence of amino acids forms the backbone of the protein.

Secondary Structure: The secondary structure refers to the local spatial arrangement of the polypeptide backbone, which is stabilized by hydrogen bonds between amino acids. The two most common secondary structures are alpha-helices and beta-sheets. These structures are important for the stability and folding of the protein.

Tertiary Structure: The tertiary structure is the three-dimensional folding of the entire polypeptide chain, including the secondary structure elements. Various interactions, such as hydrogen bonds, disulfide bridges, ionic interactions, hydrophobic interactions, and van der Waals forces, play a crucial role in stabilizing the tertiary structure. This folding brings distant parts of the polypeptide chain close together, contributing to the unique shape of the protein.

Quaternary Structure: Some proteins are composed of multiple polypeptide subunits, and the way these subunits come together forms the quaternary structure of the protein. The interactions between the individual subunits contribute to the overall structure and function of the complex protein assembly.

Learn more about protein from the link given below.

https://brainly.com/question/33861617

#SPJ6

Answer:

a. 86,942  = 8.69x10⁴

f. 56,018  = 5.60x10⁴

b. 0.00621875  = 6.22x10⁻³

g. 0.003870  = 3.87x10⁻³

c. 107062.03  = 1.07x10⁵

h. 15.9994  = 16.0

d. 4.00049  = 4.00

i. 12.011  = 12.0

e. 96  = 9.60x10¹

j. 2,000 = 2.00x10³

Explanation:

Hello,

In this case, rounding off each measurement to three significant figures, considering that if the fourth figure is five or more, the third one is rounded, we obtain:

a. 86,942  = 8.69x10⁴ (four places until the last digit and third digit is not rounded).

f. 56,018  = 5.60x10⁴ (four places until the last digit and third digit is not rounded).

b. 0.00621875  = 6.22x10⁻³ (three places until the first digit and third digit is rounded).

g. 0.003870  = 3.87x10⁻³ (three places until the first digit and third digit is not rounded).

c. 107062.03  = 1.07x10⁵ (five places until the last non-decimal digit and third digit is not rounded).

h. 15.9994  = 16.0 (those consecutive nines round the number to 16.0).

d. 4.00049  = 4.00

i. 12.011  = 12.0

e. 96  = 9.60x10¹ (exponential notation is needed since the number initially has two significant figures so an additional zero is added)

j. 2,000 = 2.00x10³ (three places until the last digit and third digit is not rounded).

Best regards.

Answer: Attractive forces between particels

Explanation:

Answer:

It is basic.

Explanation:

Bases can neutralize acids.

Answer:

mass of benzene in the lungs = 28.8 g of benzene

Explanation:

Volume of air breathed per hour = 500 mL * 12 * 60 = 360000 ml = 360 Litres of air

In 8 hours, volume of breathed air = 360 L * 8 = 2880 Litres of air

Concentration of benzene in air = 10 ppm

Note:  1 ppm = 1 mg per liter (mg/L)

10 ppm = 10 mg/L

Therefore, mass of benzene in the lungs in an 8-hour shift = 10 mg/L * 2880 L

mass of benzene in the lungs = 28800 mg

Converting to grams = 28800/1000

mass of benzene in the lungs = 28.8 g of benzene

Answer:

it moves faster when heated

Answer:

the answer is faster

Explanation:

why because water moves faster when heated

Answer:

0.773 mole

Explanation:

From the question given above, the following were obtained:

Mass of dinitrogen oxide (N₂O) = 34 g

Mole of N₂O =.?

Next, we shall determine the molar mass of N₂O. This can be obtained as follow:

Molar mass of N₂O = (14 × 2) + 16

= 28 + 16 = 44 g/mol

Finally, we shall determine the number of mole in 34.0 g of dinitrogen oxide (N₂O) as follow:

Mass of dinitrogen oxide (N₂O) = 34 g

Molar mass of N₂O = 44 g/mol

Mole of N₂O =.?

Mole = mass /Molar mass

Mole of N₂O = 34/44

Mole of N₂O = 0.773 mole

Therefore, 0.773 mole is present in 34 g of dinitrogen oxide

Answer:

6.4

Explanation:

Answer:

wide temperature range

Explanation:

Grasslands are ecosystem that covers grass and herbs. It can occur in any type of climates. The rainfall is low in grasslands but it is periodic. The temperature in the summer can exceed 100 degrees Fahrenheit in grasslands.

Savannas is a type of grasslands. It is also known as tropical grasslands. They have average annual temperatures that only vary between 70 and 78 degrees Fahrenheit.

It can be concluded that, out of the given options, that shows the characteristic of grasslands, but not savannas is option (a) " wide temperature range".

Answer: A. wide temperature range

Explanation: Got it correct on the Edgenuity 2020 quiz :)

B and C are ur answers

Answer:

Hope this may help you

Answer:

The value is [tex]m = 6.48*10^{-5} \ g [/tex]

Explanation:

From the question we are told that

The total nuclear charge is [tex]Q_t = 3.0 \ C[/tex]

The atomic number is [tex]n = 13[/tex]

The number of neutrons is [tex]n = 14[/tex]

Generally the number of protons is mathematically represented as

[tex]N_p = \frac{Q_t}{p}[/tex]

Here p is the charge on a proton with the value [tex]p = 1.60 *10^{-19} \ C[/tex]

=> [tex]N_p = \frac{3}{p}[/tex]

=> [tex]N_p = \frac{3}{1.60 *10^{-19} }[/tex]

=> [tex]N_p = 1.875*10^19 \ protons [/tex]

Generally the number of atoms present is mathematically represented as

[tex]N_a = \frac{N_p}{n }[/tex]

=> [tex]N_a = \frac{ 1.875*10^19}{13}[/tex]

=> [tex]N_a = 1.44*10^{18} \ atoms [/tex]

Generally the number of moles of atom present is mathematically represented as

[tex]N = \frac{N_a}{A_n }[/tex]

Here [tex]A_n[/tex] is the Avogadro's number with a constant value

[tex]A_n = 6.023*10^{23}[/tex]

So

[tex]N = \frac{1.44*10^{18}}{6.023*10^{23} }[/tex]

=> [tex]N = 2.4*10^{-6} \ mol[/tex]

Generally the total mass is mathematically represented as

[tex]m = N * M[/tex]

Here  M is the molar mass of   aluminum with

         [tex]M  =  27 \  g/mol[/tex]

So

        [tex]m  = 2.4*10^{-6}  * 27[/tex]

         [tex]m  = 2.4*10^{-6}  * 27[/tex]

         [tex]m  = 6.48*10^{-5} \  g [/tex]

The mass of aluminum has a total nuclear charge of 3.0 C is 6.45 * 10⁻⁵ g

nuclear charge = 3.0 C

mass of proton = 1.60 * 10⁻¹⁹ C

Number of protons = 3.0/1.60 * 10⁻¹⁹ C

Number of protons = 1.875  * 10¹⁹ protons

atomic number = 13

Number of atoms = 1.875  * 10¹⁹/13

Number of atoms = 1.44 * 10¹⁸ atoms

moles of atoms =  1.44 * 10¹⁸/ 6.02 * 10²³

moles of atoms = 2.39 * 10⁻⁶ moles

molar mass of Aluminum is 27 g

mass of aluminum = 2.39 * 10⁻⁶ * 27

mass of aluminum = 6.45 * 10⁻⁵ g

Therefore, the mass of aluminum has a total nuclear charge of 3.0 C is 6.45 * 10⁻⁵ g

Learn more about nuclear charge and atomic mass at: https://brainly.com/question/14783477

https://brainly.com/question/14227831

Answer:

The coordination number of ZrO₂ = 6

Explanation:

A crystal structure is determined by the ratio of ionic radii of the positive and negative ions present in the crystal.

The  ratio of the radii of the positive(cations) and negative(anions) is called the limiting radius ratio and it gives the coordination number of the crystal.

Limiting radius ratio = radius of cation/radius of anion

For ZrO₂:

radius of Zr ion (Zr⁴⁺) = 0.079 nm; radius of O ion (O²⁻) = 0.140 nm

Limiting radius ratio = 0.079 nm/0.140 nm = 0.564

From tables, when the limiting radius ratio value is between 0.414 - 0.732, the coordination number is six and the shape of the crystal is octahedral.

Therefore, the coordination number of ZrO₂ = 6

Answer:

5.4KL

Explanation:

Divide by 1000

Answer:

Its kinetic energy.

Explanation:

In a liquid, the molecules are so close together that there is very little empty space. A liquid also has a definite volume, because molecules in a liquid do not break away from the attractive forces. The molecules can, however, move past one another freely, and so a liquid can flow, can be poured, and assumes the shape of its container.

An increase in the temperature of a liquid causes an increase in the average speed of its molecules. As the temperature of a liquid increases, the molecules move faster thereby increasing the liquid's kinetic energy.

Answer:

pH = 2.10

Explanation:

We name an acid as diprotic because it can release two protons:

H₂A  +  H₂O  ⇄  H₃O⁺   + HA⁻     Ka₁

HA⁻  +  H₂O  ⇄  H₃O⁺   + A⁻²      Ka₂

We propose the mass balance:

Analytical concentration = [H₂A] +  [HA⁻]  + [A⁻²]

As Ka₂ is so small, we avoid the [A⁻²] so:

0.18 M = [H₂A] +  [HA⁻]

But we can not avoid the HA⁻, because the Ka₁. Ka₁'s expression is:

Ka₁ = [H₃O⁺] . [HA⁻] / [H₂A]

We propose the charge balance:

[H₃O⁺] = [HA⁻] + [A⁻²] + [OH⁻]

As we did not consider the A⁻², we can miss the term and if

Kw = H⁺ . OH⁻

We replace Kw/H⁺ = OH⁻. So the new equation is:

[H₃O⁺] = [HA⁻] + Kw / [H₃O⁺]

The acid is so concentrated, so we can avoid the term with the Kw, so:

[H₃O⁺] = [HA⁻]

In the mass balance we would have:

0.18 M = [H₂A]

We replace at Ka₁

Ka₁ = [H₃O⁺] . [HA⁻] / [H₂A]

Ka1 . 0.18 / [H₃O⁺] = [HA⁻]

We replace at the charge balance:

[H₃O⁺] = Ka1 . 0.18 / [H₃O⁺]

[H₃O⁺]² = 3.4×10⁻⁴  . 0.18

[H₃O⁺] = √(3.4×10⁻⁴  . 0.18)

[H₃O⁺] = 7.82×10⁻³

- log [H₃O⁺] = pH → - log 7.82×10⁻³

pH = 2.10

Following are the calculation to the pH:

For First ionization:

[tex][H^+] = (K_{a1} \times C)^{\frac{1}{2}}[/tex]

where

C = initial concentration of acid [tex]= 0.18\ M[/tex]

[tex][H^{+}] = (3.4 \times 10^{-4} \times 0.18 \ M)^{\frac{1}{2}}\\[/tex]

[tex][H^{+}] = 0.007\ M[/tex]

For Second ionization:

[tex][H^{+}] = K_{a2} \\\\[/tex]

[tex][ H^{+} ] = 6.7 \times 10^{-9}\ M \\[/tex]

[tex]Total [H^{+}] = 0.007\ M + 6.7 \times 10^{-9}\ M\\\\Total [H^{+}] = 0.007 \ M[/tex]

[tex]pH = -\log[H^+] \\\\pH = -\log(0.007 \ M)\\\\pH = 2.15[/tex]

Therefore, the pH is "2.15".

Learn more:

brainly.com/question/8962960