10. A(n) eclipse occurs at a full moon when Earth is directly between the moon and the sun.

In which group of the Periodic Table do most of the elements exhibit both positive and negative oxidation states?

Shtirlitz [24]

C i think but you should pick it anyway

4 0

3 years ago

The major group of organic chemicals that has double the number of hydrogen atoms as carbon or oxygen atoms, signified by the ch

gulaghasi [49]

The major group of organic chemicals that has double the number of hydrogen atoms as carbon or oxygen atoms [chemical formula (ch2o)n] is carbohydrates.

<h3>What are carbohydrates?</h3>

Carbohydrates are biological macromolecules that function as macronutrients by providing energy, which are composed of simple carbon-based molecules linked by glycosidic bonds.

In conclusion, the major group of organic chemicals that has double the number of hydrogen atoms as carbon or oxygen atoms [chemical formula (ch2o)n] is carbohydrates.

Learn more about carbohydrates here:

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5 0

2 years ago

To measure the amount of calcium carbonate in a seashell, an analytical chemist crushes a sample of the shell to a fine powder a

andreyandreev [35.5K]

The given question is complete, the complete question is:

To measure the amount of calcium carbonate (CaCO) in a seashell, an analytical chemist crushes a 4.80 g sample of the shell to a fine powder and titrates it to the endpoint with 515. mL of 0.140 M hydrogen chloride (HCl) solution. The balanced chemical equation for the reaction is: 2HCI(a)Co (a) H2Co,(aq) + 2Cl (aq)

What kind of reaction is this?

If you said this was a precipitation reaction, enter the chemical formula of the precipitate.

If you said this was an acid-base reaction, enter the chemical formula of the reactant that is acting as the base.

If you said this was a redox reaction, enter the chemical symbol of the element that is oxidized

Calculate the mass percent of CaCO in the sample. Be sure your answer has the correct number of significant digits.

Answer:

It is an acid-base reaction and the mass percent of CaCo3 is 75.2%.

Explanation:

A chemical reaction in which an insoluble salt produces from two soluble salts is termed as precipitation reaction.

A reaction in which atleast exchange of one proton takes place between the two species is termed as an acid-base reaction.

A reaction in which any of the element has a change in oxidation state is termed as redox reaction.

In the mentioned reaction, there is a transfer of H⁺, no precipitation is forming, and no change in oxidation state taking place, thus, it is an acid-base reaction.

In the acid-base reaction, the base refers to the species that accepts hydrogen ion or proton. In the given case, CO₃²⁻ is accepting H+ ion to become H₂CO₃. Hence, CO₃²⁻ is the base.

In order to calculate mass percent of CaCO₃, first there is a need to find the moles of HCl reacted for a solution,

Moles = Molarity × Volume (L)

Moles = 0.140 mol/L × 515 × 10⁻³ L

Moles = 0.0721 mol

Now from the balanced equation, one mole of CaCO₃ needs two moles of HCl.

So, moles of CaCO₃ reacted will be,

= 1/2 × 0.0721 = 0.03605 mol

The mass of calcium carbonate taking part in reaction will be,

= Moles × Molar mass

= 0.03605 × 100 gram/mole

= 3.6086 gram

Mass% of CaCO₃ = Mass of CaCO₃/Mass of sample × 100

= 3.6086 grams/4.80 grams × 100

Mass % = 75.2%

3 0

3 years ago

Determine the change in entropy for 2.7 moles of an ideal gas originally placed in a container with a volume of 4.0 L when the c

olchik [2.2K]

Answer:

The value of entropy change for the process $dS = 0.009 \frac{KJ}{K}$

Explanation:

Mass of the ideal gas = 0.0027 kilo mol

Initial volume $V_{1}$ = 4 L

Final volume $V_{2}$ = 6 L

Gas constant for this ideal gas ( R ) = $R_{u} M$

Where $R_{u}$ = Universal gas constant = 8.314 $\frac{KJ}{Kmol K}$

⇒ Gas constant R = 8.314 × 0.0027 = 0.0224 $\frac{KJ}{K}$

Entropy change at constant temperature is given by,

$dS = R log _{e} \frac{V_{2}}{V_{1}}$

Put all the values in above formula we get,

$dS = 0.0224 log _{e} [\frac{6}{4}]$

$dS = 0.009 \frac{KJ}{K}$

This is the value of entropy change for the process.

6 0

3 years ago

Explain how the colors of the visible light spectrum are organized using the terms wavelength and frequency.

Eddi Din [679]

Answer:

Visible light spectrum is a part of electromagnetic waves. The colors of the visible light spectrum are organised on the basis of their wavelength and frequency.

As the light or color having high frequency will have the shorter wavelength and vice versa, so colors in visible light spectrum arranged from highest frequency to lowest frequency or from shortest wavelength to highest wavelength. For example: The highest frequency color is violet and lowest frequency of visible light is red.

3 0

3 years ago

10. A(n) eclipse occurs at a full moon when Earth is directly between the moon and the sun.​

10. A(n) eclipse occurs at a full moon when Earth is directly between the moon and the sun.