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2 years ago

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Phenomenon: The sound of tapping on your desk is much louder and lower pitched when you listen to it with your ear pressed again

st the desk.
1. Use what you have learned to explain this phenomenon.

1 answer:

Anastasy [175]2 years ago

5 0

Answer:

hi do you want to join my padlet?

Explanation:

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Draw structures from the following names, and determine which compounds are optically active:(c) 1,2-dibromo-2-methylbutane

dolphi86 [110]

The given compound 1,2-dibromo-2-methylbutane is an optically active compound .

Because this compound does not have plane of symmetry (POS) and center of symmetry (COS) i.e. does not have di-symmetry . And also forms non superimposable mirror image . the compound is optically active .

It has chiral center.

Here , the chiral carbon is attached to the 4 distinct groups such as : methyl , ethyl , bromine , bromomethane .

<h3>What is di-symmetry?</h3>

Di-symmetry is that which have no center of symmetry and plane of symmetry and alternate axis of symmetry .

<h3>Chiral center :</h3>

Have Sp3 hybridized center (4sigma bond ) .

4 distinct group is attached to the chiral atom. form non -superimposable mirror image .

<h3>What is optical isomerism ?</h3>

Same molecular formula and same structural formula . also have same physical and chemical properties .

They differ in their behavior towards plane polarized light (ppl) .

Learn more about chiral center here:

brainly.com/question/9522537

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8 0

1 year ago

Which one of the following is a correct representation of an alpha particle?

Alex Ar [27]

Answer:

₂He⁴

Explanation:

Alpha radiations are emitted as a result of radioactive decay. The atom emit the alpha particles consist of two proton and two neutrons. Which is also called helium nuclei. When atom undergoes the alpha emission the original atom convert into the atom having mass number less than 4 and atomic number less than 2 as compared to parent atom the starting atom.

Properties of alpha radiation:

Alpha radiations can travel in a short distance.

These radiations can not penetrate into the skin or clothes.

These radiations can be harmful for the human if these are inhaled.

These radiations can be stopped by a piece of paper.

₉₂U²³⁸ → ₉₀Th²³⁴ + ₂He⁴ + energy

6 0

3 years ago

What kind of solution would have a Kb value much greater than 1?

Marta_Voda [28]

Answer:

B. a strongly basic solution

Explanation:

Kb is base dissociation constant, which indicates how completely a base dissociates into its component ions in water. The greater the Kb value, the greater the alkalinity of the solution and vice versa.

Therefore, a solution with a Kb value much greater than 1, indicates a strongly basic solution, while a solution with a Kb value less than 1, indicates a weakly basic solution.

8 0

2 years ago

In the decomposition potassium nitride, 10.65 g of nitrogen form. How much potassium nitride was present initially ?

leonid [27]

Answer:

Mass = 99.8 g

Explanation:

Given data:

Mass of potassium nitride = ?

Mass of nitrogen produced = 10.65 g

Solution:

Chemical equation:

2K₃N→ 6K + N₂

Moles of nitrogen:

Number of moles = mass/ molar mass

Number of moles = 10.65 g / 28 g/mol

Number of moles = 0.38 mol

Now we will compare the moles of nitrogen with potassium nitride.

N₂ ; K₃N

1 : 2

0.38 : 2×0.38 =0.76

Mass of potassium nitride:

Mass = molar mass × number of moles

Mass = 131.3 g/mol × 0.76 mol

Mass = 99.8 g

7 0

3 years ago

Calculate the number of moles of a gas that is present in a 7.55 L container at 45°C, if the gas exerts a pressure of 725mm Hg.

vovikov84 [41]

<u>Answer:</u> The number of moles of gas present is 0.276 moles

<u>Explanation:</u>

To calculate the number of moles of gas, we use the equation given by ideal gas:

PV = nRT

where,

P = Pressure of the gas = 725 mm Hg

V = Volume of the gas = 7.55 L

n = number of moles of gas = ?

R = Gas constant = $62.3637\text{ L.mmHg }mol^{-1}K^{-1}$

T = Temperature of the gas = $45^oC=(45+273)K=318K$

Putting values in above equation, we get:

$725mmHg\times 7.55L=n\times 62.3637\text{ L.mmHg }mol^{-1}K^{-1}\times 318K\\\\n=0.276mol$

Hence, the number of moles of gas present is 0.276 moles

4 0

3 years ago