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3 years ago

The mass of half mole of electrons is about (mass of electron= 9.1 * 10^-28g)

1 answer:

7 0

One electron has a mass of 9.10938291 x 10^−<span>31 kg. One mole of electrons contains 6.022x10^23 electrons where half of a mole is has 3.011x10^23 electrons. Therefore, the mass of half a mole of electrons would be 2.74x10^-7. Hope this answers the question. Have a nice day.</span>

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Some COCl2 is placed in a sealed flask and heated to 756 K. When equilibrium is reached, the flask is found to contain COCl2 (7.

o-na [289]

Answer:

$9.044\times 10^{-3}$ is the value of the equilibrium constant for this reaction at 756 K.

Explanation:

$COCl_2\rightleftharpoons CO+Cl_2$

Equilibrium concentration of $COCl_2$

$[COCl_2]=7.40\times 10^{-4} M$

Equilibrium concentration of $CO$

$[CO]=3.76\times 10^{-2} M$

Equilibrium concentration of $Cl_2$

$[Cl_2]=1.78\times 10^{-4} M$

The expression of an equilibrium constant can be written as;

$K_c=\frac{[CO][Cl_2]}{[COCl_2]}$

$=\frac{3.76\times 10^{-2}\times 1.78\times 10^{-4}}{7.40\times 10^{-4}}$

$K_c=9.044\times 10^{-3}$

$9.044\times 10^{-3}$ is the value of the equilibrium constant for this reaction at 756 K.

5 0

3 years ago

A colorless solution is known to contain one of these ions. Which ion is present if adding dilute HCl produces a white precipita

marta [7]

Answer:

The correct answer is option D.

Explanation:

All the cations given belong to the group-1 cation and will give precipitate of their respective chlorides when HCl is added to their aqueous solution.

$Ag^+(aq)+HCl(aq)\rightarrow AgCl(s)+H^+(aq)$

$Cu^{2+}+(aq)+2HCl(aq)\rightarrow CuCl_2(s)+2H^+(aq)$

$Hg_{2}^{2+}+(aq)+2HCl(aq)\rightarrow Hg_2Cl_2(s)+2H^+(aq)$

$Pb^{2+}+(aq)+2HCl(aq)\rightarrow PbCl_2(s)+2H^+(aq)$

All the precipitates are insoluble in cold water but out of all these only lead(II) chloride is soluble in warm water.

4 0

2 years ago

Calculate the number of photons that would be contained in a laserpulse with a wavelength of 287 nm that contained 4.35 mJ of en

OLEGan [10]

Answer:

3.46 ⋅ 10 − 19 J

Explanation:

The energy of a photon is proportional to its frequency,

4 0

2 years ago

While playing soccer, Carla slides across one of the lines on the field. When she stands up, what base does she dust off? calciu

babunello [35]

The soccer field has been placed with the outlines of the slaked lime. The chemical dust off from the falling has been calcium hydroxide.

<h3>What is slaked lime?</h3>

The boundary wall to the soccer or the other field has been marked with slaked lime powder. The chemical has the ability to react with bacteria and act as a disinfectant.

The slaked lime chemically is a white powder of calcium hydroxide. Thus, after falling on the soccer field, the chemical dusted off by Carla is calcium hydroxide. Thus, option A is correct.

Learn more about slaked lime, here:

brainly.com/question/497323

6 0

2 years ago

What is isotope <br>the percentage of the solid components of soil

zubka84 [21]

Answer:

an isotope consists of two or more forms of the same elements that contains equal number of protons but different number of neutrons in their nuclei but differ in relative atomic mass but not in chemical properties

The percentage of soil components of the soil is: inorganic components

-soil particles

-mineral elements = 45%

-water or moisture= 25%

- air= 25%

organic components

-humus or decayed organic matter= 5%

-living organisms

4 0

2 years ago