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2 years ago

Now that you have exercised, walked your

Chemistry

1 answer:

ASHA 777 [7]2 years ago

4 0

Answer: The moles of melatonin are 0.000043

Explanation:

According to avogadro's law, 1 mole of every substance weighs equal to its molecular mass and contains avogadro's number $6.023\times 10^{23}$ of particles.

To calculate the moles, we use the equation:

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

Given mass of melatonin = 0.01 g

Molar mass of melatonin $(C_{13}H_{16}N_2O_2)$ = 232.28 g/mol

$\text{Number of moles of melatonin}=\frac{0.01 g}{232.28g/mol}=0.000043mol$

Thus the moles of melatonin in 0.01 g are 0.000043

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Give an example of chemical equilibrium you have come across into your day-to-day life. Explain how it meets the definition of e

Roman55 [17]

There are many examples of chemical equilibrium all around you. One example is a bottle of fizzy cooldrink. In the bottle there is carbon dioxide (CO2) dissolved in the liquid. There is also CO2 gas in the space between the liquid and the cap

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2 years ago

Which of the following statements best describes why carbon can form a variety of organic compounds? Carbon atoms bond readily w

olga_2 [115]

Answer:
Carbon readily forms covalent bonds with other carbon atoms.

Explanation:
As we know approximately more than 95 % compounds, either isolated, discovered or synthesized belongs to organic compounds containing carbon atoms.
This great diversity of organic compounds is due to following facts.

1) Catenation:
Carbon has a peculiar behavior of self linkage. This self linkage of one carbon with another is called as catenation. In this way carbon can form a long chain of carbon atom. A branching can also take place when one carbon is bonded further to three of four carbon atoms.

2) Isomerism:
Secondly the carbon containing compounds show isomerism. In which molecular formula is same but structural formula is different. For example molecular formula C₅H₁₂ can make following compounds,

a) n-Pentane

b) 2-Methylbutane

c) 2,2-Dimethylpropane

3) Multiple Bonds:
Carbon can form multiple bonds i.e double bond like in alkenes and triple bonds like in alkyne.

Due to these factors carbon gets very high number of opportunities to form large number of compounds.

7 0

3 years ago

A student isolated 7.2 g of 1-bromobutane reacting equimolar amounts of 1-butanol (10 ml) and NaBr (11.1 g) in the presence of s

Alla [95]

Answer: The percent yield of the 1-bromobutane is 48.65 %

Explanation:

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$ .....(1)

For NaBr:

Given mass of NaBr = 11.1 g

Molar mass of NaBr = 103 g/mol

Putting values in equation 1, we get:

$\text{Moles of NaBr}=\frac{11.1g}{103g/mol}=0.108mol$

The chemical equation for the reaction of 1-butanol and NaBr is:

$\text{1-butanol + NaBr}\rightarrow \text{1-bromobutane}$

By Stoichiometry of the reaction

1 mole of NaBr produces 1 mole of 1-bromobutane

So, 0.108 moles of NaBr will produce = $\frac{1}{1}\times 0.108=0.108$ moles of 1-bromobutane

Now, calculating the mass of 1-bromobutane from equation 1, we get:

Molar mass of 1-bromobutane = 137 g/mol

Moles of 1-bromobutane = 0.108 moles

Putting values in equation 1, we get:

$0.108mol=\frac{\text{Mass of 1-bromobutane}}{137g/mol}\\\\\text{Mass of 1-bromobutane}=(0.108mol\times 137g/mol)=14.80g$

To calculate the percentage yield of 1-bromobutane, we use the equation:

$\%\text{ yield}=\frac{\text{Experimental yield}}{\text{Theoretical yield}}\times 100$

Experimental yield of 1-bromobutane = 7.2 g

Theoretical yield of 1-bromobutane = 14.80 g

Putting values in above equation, we get:

$\%\text{ yield of 1-bromobutane}=\frac{7.2g}{14.80g}\times 100\\\\\% \text{yield of 1-bromobutane}=48.65\%$

Hence, the percent yield of the 1-bromobutane is 48.65 %

5 0

2 years ago

Part A Which acid in each of the following pairs has the stronger conjugate base? Match the words in the left column to the appr

vichka [17]

Answer:

H₂S

H₂CO₃

NH₄⁺

Explanation:

Which acid in each of the following pairs has the stronger conjugate base?

According to Bronsted-Lowry acid-base theory, the weaker an acid, the stronger its conjugate acid. Especially for weak acids, pKa gives information about the strength of such acid. The higher the pKa, the weaker the acid.

Of the acids HCl or HF, the one with the stronger conjugate base is HF because it is a weak acid.

Of the acids H₂S or HNO₂, the one with the stronger conjugate base is H₂S because it is a weaker acid. pKa (H₂S) = 7.04 > pKa (HNO₂) = 3.39

Of the acids H₂CO₃ or HClO₄, the one with the stronger conjugate base is H₂CO₃ because it is a weak acid.

Of the acids HF or NH₄⁺, the one with the stronger conjugate base is NH₄⁺ because it is a weaker acid. pKa (HF) = 3.17 < pKa (NH₄⁺) = 9.25

6 0

2 years ago

A CaCl2 solution is given to increase blood levels of calcium. If a patient receives 6.1 mL of a 12 % (m/v) CaCl2 solution, how

Yuliya22 [10]

Mass of CaCl₂ = 0.732 g

<h3>Further explanation</h3>

The concentration of a substance can be expressed in several quantities such as moles, percent (%) weight / volume,), molarity, molality, parts per million (ppm) or mole fraction. The concentration shows the amount of solute in a unit of the amount of solvent.

$\tt \%(m/v)\rightarrow 12\%=\dfrac{mass~CaCl_2}{volume~of~solution}\times 100\%\\\\mass~CaCl_2=12\%\times 6.1\div 100\%\\\\mass~CaCl_2=0.732~g$

5 0

3 years ago