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3 years ago

How did admitting Mendeleev deal with elements that had not yet been discovered

1 answer:

7 0

Mendeleev organized his table by atomic mass, rather than atomic radius. He was able to extrapolate where certain undiscovered elements should be on the table based on that.

For example, he said that since Calcium has mass of 40g and Titanium has a mass of 48 g, there must be some element between them with atomic mass of 44 g. That was later discovers to be scandium.

Hope this helps

You might be interested in

How many grams of Aspirin (acetylsalicylic acid) should we form in this reaction if we started with 2.08g of Salicyclic Acid?

Kamila [148]

Taking into account the reaction stoichiometry, 2.713 grams of aspirin are formed when 2.08 grams of salicyclic acid reacts.

<h3>Reaction stoichiometry</h3>

In first place, the balanced reaction is:

C₄H₆O₃ + C₇H₆O₃ (Salicyclic Acid) →C₉H₈O₄ (aspirin) + C₂H₄O₂

By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:

C₄H₆O₃: 1 mole
C₇H₆O₃: 1 mole
C₉H₈O₄: 1 mole
C₂H₄O₂: 1 mole

The molar mass of the compounds is:

C₄H₆O₃: 102 g/mole
C₇H₆O₃: 138 g/mole
C₉H₈O₄: 180 g/mole
C₂H₄O₂: 60 g/mole

Then, by reaction stoichiometry, the following mass quantities of each compound participate in the reaction:

C₄H₆O₃: 1 mole ×102 g/mole= 102 grams
C₇H₆O₃: 1 mole ×138 g/mole= 138 grams
C₉H₈O₄: 1 mole ×180 g/mole= 180 grams
C₂H₄O₂: 1 mole ×60 g/mole= 60 grams

<h3>Mass of aspirin formed</h3>

The following rule of three can be applied: if by reaction stoichiometry 138 grams of salicyclic acid form 180 grams of aspirin, 2.08 grams of salicyclic acid form how much mass of aspirin?

$mass of aspirin=\frac{2.08 grams of salicyclic acidx 180 grams of aspirin}{138 grams of salicyclic acid}$

<u><em>mass of aspirin= 2.713 grams</em></u>

Then, 2.713 grams of aspirin are formed when 2.08 grams of salicyclic acid reacts.

Learn more about the reaction stoichiometry:

brainly.com/question/24741074

brainly.com/question/24653699

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7 0

2 years ago

A Metal mass of 71.68g occupies a volume of 8cm^3. Calculate the density

Damm [24]

Density = mass
--------------
volume

= 71.68
-------------
8

= 8.96 g/cm3.

Hope this helps!

5 0

4 years ago

Which of the following equations expresses the work-kinetic energy theorem?

Anna71 [15]

Answer:

W = ΔKE = 1/2mv₂⁽²⁾ - 1/2mv₁⁽²⁾

Explanation:

Work means Change In Kinetic Energy.

Kinetic-Energy is equal to change in velocity multiplied by mass and divided by 2

∴ KE = 1/2m²

Change in Kinetic-Energy =KE₂ - KE₁

=1/2mv₂⁽²⁾ - 1/2mv₁⁽²⁾

4 0

3 years ago

3) a) (2 points) Label the 1H NMR spectrum of adipic acid by identifying key resonances. Use letters (a, b, c, etc.) to match Hs

Bess [88]

Answer:

The label of spectrum is attached.

Explanation:

adipic acid is equal to:

COOH - CH2 - CH2 - CH2 - CH2 - COOH

(1) (2) (3) (3) (2) (1)

The structure of adipic acid indicates that it has 3 equivalent carbons, therefore it should have 3 peaks in the spectrum:

The first peak at approximately 172 ppm is from carbon (1) COOH. The second peak is at approximately 23 ppm and is by carbon number (3) CH2. and the third peak is at approximately 37 ppm and is due to group number (2) CH2.

3 0

3 years ago

What is the average amount of energy produced by the motion of air molecules air is call

stepan [7]

T<span>he average amount of energy produced by the motion of air molecules is called air temperature.</span>

3 0

4 years ago