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3 years ago

A submersible is used to _____.

Chemistry

1 answer:

Vlad1618 [11]3 years ago

6 0

Answer:

The term submersible is often used to differentiate from other underwater vessels known as submarines, in that a submarine is a fully autonomous craft.

Explanation:

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What is the entropy change of the surroundings

KiRa [710]

Answer: The entropy change of the surroundings will be -17.7 J/K mol.

Explanation: The enthalpy of vapourization for 1 mole of acetone is 31.3 kJ/mol

Amount of Acetone given = 10.8 g

Number of moles is calculated by using the formula:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Molar mass of acetone = 58 g/mol

Number of moles = $\frac{10.8}{58}=0.1862moles$

If 1 mole of acetone has 32.3 kJ/mol of enthalpy, then

0.1862 moles will have = $\frac{32.3}{1}\times 0.1862=5.828kJ/mol$

To calculate the entropy change for the system, we use the formula:

$\Delta S_{sys}=\frac{\Delta H_{vap}}{T(\text{ in K)}}$

Temperature = 56.2°C = (273 + 56.2)K = 329.2K

Putting values in above equation, we get

$\Delta S_{sys}=\frac{5.828}{329.2}=0.0177kJ/Kmol=17.7J/Kmol$ (Conversion Factor: 1 kJ = 1000J)

At Boiling point, the liquid phase and gaseous phase of acetone are in equilibrium. Hence,

$\Delta S_{system}+\Delta S_{surrounding}=0$

$\Delta S_{surrouding}=-\Delta S_{system}=-17.7J/Kmol$

5 0

3 years ago

Give the structure that corresponds to the following molecular formula and 1H NMR spectrum: C4H10O2: δ 1.36 (3H, d, J = 5.5 Hz);

kondor19780726 [428]

Answer:

For the determination of a structure through its NMR it is necessary to know its molecular formula as well as the delta values, its coupling and the shift of each signal.

The separation produced is called coupling constant J and is measured in Hz. If the split is produced by two equal protons (equal J) a triple signal known as triplet is produced and if produced by three equal protons, the signal is quadruple and is known as quadruplet. The magnitude of the coupling is varied, depending on the relative disposition of the coupled protons (elevations that separate them, arrangement, spatial arrangement)

OH CH2 CH2 CH2 CH2 OH

(A) (B) (C)

1,4-butanediol

In the case of the molecule to study the signal at 1.36 shows a doublet, which corresponds to the hydrogen (C), is split in two for each different proton on the same carbon or on neighboring carbons.

At 3.32 ocurrs a singlet, wich belong to hidrogen (B). The last signal is a quintet, at 4.63 belonging to the hydrogen (C)

Explanation

Nuclear magnetic resonance NMR is a physical phenomenon based on the mechanical-quantum properties of atomic nuclei. NMR also refers to the family of scientific methods that explore this phenomenon to study molecules, macromolecules, as well as tissues and whole organisms.

NMR takes advantage of the fact that atomic nuclei resonate at a frequency directly proportional to the force of a magnetic field exerted, in accordance with the Larmor precession frequency equation, to subsequently disturb this alignment with the use of an alternating magnetic field, of orthogonal orientation.

The behavior of the nuclei in the magnetic field can be influenced in multiple ways, to give different types of information, but the basic information obtained is:

Frequency at which each particular nuclei comes out, displacement.
Number of nucleis of each type, integral.
Number and arrangement of nearby nuclei, multiplicity.

6 0

3 years ago

How do I solve the following word problem: The half-life of Phosphorus - 32 is 14.3 days. It is used to study a plant's use of f

BaLLatris [955]

Half life is the time that it takes for half of the original value of some amount of a radioactive element to decay.

We have the following equation representing the half-life decay:

$A=A_o\times2^{(-\frac{t}{t_{half}})_{}_{}}$

A is the resulting amount after t time

Ao is the initial amount = 50 mg

t= Elapsed time

t half is the half-life of the substance = 14.3 days

We replace the know values into the equation to have an exponential decay function for a 50mg sample

$A=\text{ 50 }\times2^{\frac{-t}{14.3}}$

That would be the answer for a)

To know the P-32 remaining after 84 days we have to replace this value in the equation:

$\begin{gathered} A=\text{ 50 }\times2^{\frac{-84}{14.3}} \\ A=0.85\text{ mg} \end{gathered}$

So, after 84 days the P-32 remaining will be 0.85 mg

4 0

1 year ago

When 0.42 g of a compound containing C, H, and O is burned completely, the products are 1.03 g CO2 and 0.14 g H2O. The molecular

Luda [366]

Answer: The empirical and molecular formula for the given organic compound is $C_2H_2O_4$ and $C_6H_4O_2$

Explanation:

The chemical equation for the combustion of hydrocarbon having carbon, hydrogen and oxygen follows:

$C_xH_yO_z+O_2\rightarrow CO_2+H_2O$

where, 'x', 'y' and 'z' are the subscripts of Carbon, hydrogen and oxygen respectively.

We are given:

Mass of $CO_2=1.03g$

Mass of $H_2O=0.14g$

We know that:

Molar mass of carbon dioxide = 44 g/mol

Molar mass of water = 18 g/mol

For calculating the mass of carbon:

In 44g of carbon dioxide, 12 g of carbon is contained.

So, in 1.03 g of carbon dioxide, $\frac{12}{44}\times 1.03=0.28g$ of carbon will be contained.

For calculating the mass of hydrogen:

In 18g of water, 2 g of hydrogen is contained.

So, in 0.14 g of water, $\frac{2}{18}\times 0.14=0.016g$ of hydrogen will be contained.

Mass of oxygen in the compound = (0.42) - (0.28 + 0.016) = 0.124 g

To formulate the empirical formula, we need to follow some steps:

Step 1: Converting the given masses into moles.

Moles of Carbon = $\frac{\text{Given mass of Carbon}}{\text{Molar mass of Carbon}}=\frac{0.28g}{12g/mole}=0.023moles$

Moles of Hydrogen = $\frac{\text{Given mass of Hydrogen}}{\text{Molar mass of Hydrogen}}=\frac{0.016g}{1g/mole}=0.016moles$

Moles of Oxygen = $\frac{\text{Given mass of oxygen}}{\text{Molar mass of oxygen}}=\frac{0.124g}{16g/mole}=0.00775moles$

Step 2: Calculating the mole ratio of the given elements.

For the mole ratio, we divide each value of the moles by the smallest number of moles calculated which is 0.00775 moles.

For Carbon = $\frac{0.023}{0.00775}=2.96\approx 3$

For Hydrogen = $\frac{0.016}{0.00775}=2.06\approx 2$

For Oxygen = $\frac{0.00775}{0.00775}=1$

Step 3: Taking the mole ratio as their subscripts.

The ratio of C : H : O = 3 : 2 : 1

Hence, the empirical formula for the given compound is $C_3H_{2}O_1=C_3H_2O$

For determining the molecular formula, we need to determine the valency which is multiplied by each element to get the molecular formula.

The equation used to calculate the valency is :

$n=\frac{\text{molecular mass}}{\text{empirical mass}}$

We are given:

Mass of molecular formula = 108.10 g/mol

Mass of empirical formula = 54 g/mol

Putting values in above equation, we get:

$n=\frac{108.10g/mol}{54g/mol}=2$

Multiplying this valency by the subscript of every element of empirical formula, we get:

$C_{(3\times 2)}H_{(2\times 2)}O_{(1\times 2)}=C_6H_4O_2$

Thus, the empirical and molecular formula for the given organic compound is $C_3H_2O$ and $C_6H_4O_2$

6 0

3 years ago

Oxygen-Carbon Dioxide Exchange

leonid [27]

Answer:

Answer is below with the steps in order

Explanation:

4) Blood picks up carbon dioxide from the body

7) Heart pumps carbon dioxide rich blood to the lungs

8) Inhale

9) Nose traps germs in air

10) Air moves down the trachea

3) Air moves through bronchi into the bronchioles

6) Alveoli receive oxygen pass to blood

9) Oxygen passes into the blood

11) Alveoli receives carbon dioxide from the blood

12) Oxygen-rcih blood flows to the heart

3) Carbon Dioxide moves from bonchioles to bronchi

13)Carbon dioxide flows up

1) Heart pumps oxygen-rich blood to the body

The last four of five steps could be switched up a little bit since it all happens synchronously, but this is the most accurate interpretation.

8 0

2 years ago