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2 years ago

How was the periodic law rearranged to become the periodic table, and what is its purpose?

Chemistry

1 answer:

alexandr402 [8]2 years ago

7 0

Answer:

At earlier times elements were arrangrd on the basis of their atomic masses to study their properties easily but there were various problems like isotopes needs different position in perodic table.

After discovery of atomic number modern periodic table was created on the basis of atomic number (number of proton) that is unique for each element and varies regularly. So study of a group of elements is much easier than each element seperately that is why modern periodic table was formed.

Explanation:

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Which type of force does a magnet use to move a nail?

galben [10]

Answer:

C maybe

Explanation:

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1 year ago

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chemistry A basketball is inflated to a pressure of 1.10 atm in a 28.0°C garage. What is the pressure of the basketball outside

butalik [34]

Answer : The final pressure of the basketball is, 0.990 atm

Explanation :

Gay-Lussac's Law : It is defined as the pressure of the gas is directly proportional to the temperature of the gas at constant volume and number of moles.

$P\propto T$

or,

$\frac{P_1}{P_2}=\frac{T_1}{T_2}$

where,

$P_1$ = initial pressure = 1.10 atm

$P_2$ = final pressure = ?

$T_1$ = initial temperature = $28.0^oC=273+28.0=301.0K$

$T_2$ = initial temperature = $-2.00^oC=273+(-2.00)=271.0K$

Now put all the given values in the above equation, we get:

$\frac{1.10atm}{P_2}=\frac{301.0K}{271.0K}$

$P_2=0.990atm$

Thus, the final pressure of the basketball is, 0.990 atm

7 0

2 years ago

150 mL of 0.25 mol/L magnesium chloride solution and 150 mL of 0.35 mol/L silver nitrate solution are mixed together. After reac

Murljashka [212]

Answer:

$0.175\; \rm mol \cdot L^{-1}$ .

Explanation:

Magnesium chloride and silver nitrate reacts at a $2:1$ ratio:

$\rm MgCl_2\, (aq) + 2\, AgNO_3\, (aq) \to Mg(NO_3)_2 \, (aq) + 2\, AgCl\, (s)$ .

In reality, the nitrate ion from silver nitrate did not take part in this reaction at all. Consider the ionic equation for this very reaction:

$\begin{aligned}& \rm Mg^{2+} + 2\, Cl^{-} + 2\, Ag^{+} + 2\, {NO_3}^{-} \\&\to \rm Mg^{2+} + 2\, {NO_3}^{-} + 2\, AgCl\, (s)\end{aligned}$ .

The precipitate silver chloride $\rm AgCl$ is insoluble in water and barely ionizes. Hence, $\rm AgCl\!$ isn't rewritten as ions.

Net ionic equation:

$\begin{aligned}& \rm Ag^{+} + Cl^{-} \to AgCl\, (s)\end{aligned}$ .

Calculate the initial quantity of nitrate ions in the mixture.

$\begin{aligned}n(\text{initial}) &= c(\text{initial}) \cdot V(\text{initial}) \\ &= 0.25\; \rm mol \cdot L^{-1} \times 0.150\; \rm L \\ &= 0.0375\; \rm mol \end{aligned}$ .

Since nitrate ions $\rm {NO_3}^{-}$ do not take part in any reaction in this mixture, the quantity of this ion would stay the same.

$n(\text{final}) = n(\text{initial}) = 0.0375\; \rm mol$ .

However, the volume of the new solution is twice that of the original nitrate solution. Hence, the concentration of nitrate ions in the new solution would be $(1/2)$ of the concentration in the original solution.

$\begin{aligned} c(\text{final}) &= \frac{n(\text{final})}{V(\text{final})} \\ &= \frac{0.0375\; \rm mol}{0.300\; \rm L} = 0.175\; \rm mol \cdot L^{-1}\end{aligned}$ .

6 0

2 years ago

a 360mg sample of sugar (molar mass of 180 g/mol) is dissolved in enough water to produce 200mL of solution. after the sugar is

Pie

360 mg / 1000 => 0.36 g

molar mass => 180 /mol

number of moles:

mass of solute / molar mass

0.36 / 180 => 0.002 moles

Volume solution = 200 mL / 1000 => 0.2 L

M = n / V

M = 0.002 / 0.2

M = 0.01 mol/L

hope this helps!

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2 years ago

Which of the following is the correct structure of 2-methyl-3-heptene

astraxan [27]

Answer:

answer d

Explanation:

methy group is in the second position while the double bond is in the third position

8 0

2 years ago

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