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2 years ago

Write the merits and demerits of Mendeleev periodic table in points and explain each of them in short

Chemistry

1 answer:

elena-14-01-66 [18.8K]2 years ago

6 0

Answer:

merits of mendeleev periodic table are:

it was first scientific and systamatic study of different element.
there were may gaps for in discovered elements.After their discovery the got their proper place in table.
with the help of mendeleev periodic table , properties of several elements were studied correctly.

demerits of mendeleev periodic table

it could not arrange hydrogen as it shows the property of both alkali and halogens.
it could not arrange isotopes because they have different atomic weight but same atomic number.
it could not arrange Lanthanides and Actinides.

hope these points helped you

need more points then comment it .

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Aqueous hydrochloric acid HCl reacts with solid sodium hydroxide NaOH to produce aqueous sodium chloride NaCl and liquid water H

allochka39001 [22]

Answer : The theoretical yield of water formed from the reaction is 0.54 grams.

Solution : Given,

Mass of HCl = 1.1 g

Mass of NaOH = 2.1 g

Molar mass of HCl = 36.5 g/mole

Molar mass of NaOH = 40 g/mole

Molar mass of $H_2O$ = 18 g/mole

First we have to calculate the moles of HCl and NaOH.

$\text{ Moles of }HCl=\frac{\text{ Mass of }HCl}{\text{ Molar mass of }HCl}=\frac{1.1g}{36.5g/mole}=0.030moles$

$\text{ Moles of }NaOH=\frac{\text{ Mass of }NaOH}{\text{ Molar mass of }NaOH}=\frac{2.1g}{40g/mole}=0.525moles$

Now we have to calculate the limiting and excess reagent.

The balanced chemical reaction is,

$HCl+NaOH\rightarrow NaCl+H_2O$

From the balanced reaction we conclude that

As, 1 mole of HCl react with 1 mole of NaOH

So, 0.030 mole of HCl react with 0.030 mole of NaOH

From this we conclude that, $NaOH$ is an excess reagent because the given moles are greater than the required moles and $HCl$ is a limiting reagent and it limits the formation of product.

Now we have to calculate the moles of $H_2O$

From the reaction, we conclude that

As, 1 mole of $HCl$ react to give 1 mole of $H_2O$

So, 0.030 moles of $HCl$ react to give 0.030 moles of $H_2O$

Now we have to calculate the mass of $H_2O$

$\text{ Mass of }H_2O=\text{ Moles of }H_2O\times \text{ Molar mass of }H_2O$

$\text{ Mass of }H_2O=(0.030moles)\times (18g/mole)=0.54g$

Therefore, the theoretical yield of water formed from the reaction is 0.54 grams.

6 0

3 years ago

What is the half-life (in seconds) of a zero-order reaction which has an initial reactant concentration of 0.884 M with a k valu

pantera1 [17]

Answer: 8.15s


Explanation:


1) A first order reaction is that whose rate is proportional to the concenration of the reactant:


r = k [N]


r = - d[N]/dt =


=> -d[N]/dt = k [N]


2) When you integrate you get:


N - No = - kt


3) Half life => N = No / 2, t = t'


=> No - No/ 2 = kt' => No /2 = kt' => t' = (No/2) / k


3) Plug in the data given: No = 0.884M, and k = 5.42x10⁻²M/s


t' = (0.884M/2) / (5.42x10⁻²M/s) = 8.15s

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3 years ago

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sattari [20]

Answer:

True

Explanation:

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Explain the meaning of each term in the symbol aXz

Ede4ka [16]

AXz

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It is a chemical notation of nuclide

Here X is the symbol of the element

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A=n+p(sum of protons and neutrons)

Z is the atomic number.

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Hers X is C, symbol of carbon

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Natalka [10]

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Write the merits and demerits of Mendeleev periodic table in points and explain each of them in short​

Write the merits and demerits of Mendeleev periodic table in points and explain each of them in short