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3 years ago

The characteristic bright–line spectrum of potassium is produced when electrons

Chemistry

1 answer:

OLEGan [10]3 years ago

8 0

Answer: B.

Explanation:

When the electron changes levels, it decreases energy and the atom emits photons. The photon is emitted with the electron moving from a higher energy level to a lower energy level. The energy of the photon is the exact energy that is lost by the electron moving to its lower energy level.

Hope this helps!

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noname [10]

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4 0

3 years ago

Electric service has accumulated on an object is referred to as

lara31 [8.8K]

Answer:

Static Electricity! :)

Explanation:

3 0

3 years ago

Hiii pls help me to write out the ionic equation

emmasim [6.3K]

Answer:

STEP I

This is the balanced equation for the given reaction:-

$2KOH_{(aq)} + H_2SO_4{}_{(aq)} \rightarrow K_2SO_4{}_{(aq)} + 2H_2O_{(l)}$

STEP II

The compounds marked with (aq) are soluble ionic compounds. They must be

broken into their respective ions.

see, in the equation KOH, H2SO4, and K2SO4 are marked with (aq).

On breaking them into their respective ions :-

2KOH -> 2K+ + 2OH-
H2SO4 -> 2H+ + (SO4)2-
K2SO4 -> 2K+ + (SO4)2-

STEP III

Rewriting these in the form of equation

$\underline{\pmb{2K^+} }+ 2OH^- + 2H^+ + \pmb{\underline{{SO_4{}^{2-}}} \: \rightarrow \: \underline{\pmb{2K^+}}} + \underline{\pmb{SO_4{}^{2-}}} + 2H_2O$

STEP IV

Canceling spectator ions, the ions that appear the same on either side of the equation

(note: in the above step the ions in bold have gotten canceled.)

$\boxed{ \mathfrak{ \red{ 2OH^-{}_{(aq)} + 2H^+{(aq.)} \rightarrow H_2O{}_{(l)}}}}$

This is the net ionic equation.

____________________________

$\\$

$\mathfrak{\underline{\green{ Why\: KOH \:has\: been\: taken\: as\: aqueous ?}}}$

KOH has been taken as aqueous because the question informs us that we have a solution of KOH. by solution it means that KOH has been dissolved in water before use.

[Alkali metal hydroxides are the only halides soluble in water ]

4 0

3 years ago

Write the balanced chemical equation for the following: The destruction of a marble statuary by acid rain: aqueous nitric acid r

Mashcka [7]

Answer: The coefficient in front of nitric acid is 2

Explanation:

According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.

The salts which are soluble in water are designated by symbol (aq) and those which are insoluble in water and remain in solid form are represented by (s) after their chemical formulas. Liquids are represented by (l) and gases are represented by (g).

The balanced chemical reaction is :

$CaCO_3(s)+2HNO_3(aq)\rightarrow Ca(NO_3)_2(aq)+CO_2(g)+H_2O(l)$

7 0

3 years ago

Consider the reaction. 4 k(s) + o2(g) s 2 k2o(s) the molar mass of k is 39.09 g>mol and that of o 32.00 g>mol. Without doi

Scilla [17]

Answer : The correct option is (d) 1.5 g K, 0.38 g O₂

Explanation :

The molar masses of potassium and oxygen are very close to each other. Therefore we can assume them to be equal. If we assume that, then according to reaction stoichiometry, 4 moles of K are needed to react with 1 mol of O₂. Since the molar masses are assumed to be equal , we can say that the mass of potassium needed to react with that of oxygen should be 4 times the mass of oxygen.

From the given options, the only option that has less amount of K is option d.

Here, 0.38 g of oxygen needs 0.38 x 4 = 1.52 g of K. But the given mass of potassium is 1.5 g which is less. This indicates that potassium is the limiting reactant as we do not have enough potassium to completely react with all of the oxygen.

Therefore option d is the correct option

3 0

3 years ago

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