The coefficient "2" have to be included infront of and also in order come balance a chemical reaction.

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Law of conservation of mass says that the mass have the right to neither be developed nor it is in destroyed, however it deserve to only be transformed from one form to another. It always remain conserved.

In a chemistry reaction, the number of individual atoms on the reactant side have to be same to the variety of individual atom on the product side. Every the balanced chemical reaction follow law of preservation of mass.

For the provided chemical reaction, the balanced equation follows:


On reactant side:

Number of potassium atom = 2

Number of nitrogen atoms = 2

Number of oxygen atoms = 6

On product side:

Number that potassium atoms = 2

Number of nitrogen atoms = 2

Number that oxygen atoms = 6

Thus, the coefficient "2" must be added infront the and also in order to balance a chemistry reaction.

Answer from: mochoa4

The correct answer is c

Explanation: that is the ideal answer

Answer from: gugu1004

FeCl₃ + 3 NaOH → 3 NaCl + Fe(OH)₃


To balance a chemical reaction, us should maintain the stichiometry of every elements.Also, us should demonstrate the conservation of fixed that states "The fixed doe not damaged or developed from nothing yet it have the right to transferred from type to one more one".Thus, by balancing the chemistry reaction us are applying the preservation of mass.That in our example, the number of atoms of each element in the reacting and products sides need to be equal.

Fe is 1.0 atom in both sides.

Na, Cl, O, and also H space 3.0 atoms in both sides.

and for this reason the mass is conserved through balancing the chemistry reactionc.

Answer from: nerual0503

Part 1: 2KNO3 → 2KNO2 + O2 is the balanced equation.

Part 2: The conversation that mass the demonstrates that there is no detectable adjust in the full quantity the matter present in the


Part 1: to balance a chemistry equation, the number of atoms in the reactants and the assets must be equal. So, the coefficient 2 included before KNO3 and also KNO2 come balance the equation.

2KNO3 → 2KNO2 + O2

Part 2:

This chemistry reaction demonstrates the conversation the mass the demonstrates the there is no detectable adjust in the complete quantity of matter current when chemical adjust occurs (matter converts from one kind to another) or physical adjust occurs (changes amongst solid, liquid, or gas states).

This is clear in the balanced equation.

Answer from: Hrjohnson2004


The given chemical equation is the following:


On the left side of the chemical equation, there room 1 Mercury atom, 1 Sulfur (or Sulphur) atom, and two oxygen atoms, vice versa, on the right side that the chemical equation, there room 1 Mercury atom, 1 Sulfur (or Sulphur) atom, yet 3 oxygen atoms. Currently let"s balance the offered equation!

The well balanced equation will be:


The left side of the over chemical equation has actually the adhering to configuration:

Number of Mercury atom = 2*1 = 2.

Number that Sulfur (or Sulphur) atom = 2*1 = 2.

Number the oxygen atoms = 3*2 = 6.

The right side of the over chemical equation has actually the complying with configuration:

Number of Mercury atoms = 2*1 = 2.

Number the Sulfur (or Sulphur) atom = 2*1 = 2.

Number of oxygen atoms = 2 + (2*2) = 2+4 = 6.

Hence, ~ above left hand side of the chemistry equation, the coefficient 2 has been included to the Mercury sulphide (HgS) and also the coefficient 3 has actually been added to oxygen molecule (O₂), conversely, on the ideal hand next of the chemistry equation, the coefficient 2 has actually been presented with the Mercury oxide (aka Mercuric oxide)—HgO—and the coefficient 2 has actually been included with the Sulphur dioxide (SO₂).

In this context, the preservation of mass, in simple—non-bookish—words, way that there space equal number atoms on both sides of the equation. No issue is either produced during or after ~ the reaction not any matter was destroyed. Together in the instance of aforementioned balanced equation, there are 2 mercury, 2 suphur and 6 oxygen atoms on both political parties of the equation, demostrating the preservation of fixed after the reaction.



To tell girlfriend the kind of the chemical reaction occuring in between aluminum and also copper nitrate, let me explain you the reaction first, which is, to trust me, the saddest reaction you"d ever before see. The (balanced) reaction is the following:


Why is this the saddest reaction? Well, according to the activity series (aka reactivity series), Aluminum (Al) is more reactive 보다 Copper (Cu). Since Al is more reactive than Cu, the (Al) kicks out Cu indigenous Cu(NO₃)₂ compound and also takes that is place, leaving Cu alone ~ the reaction. :(

Such kind of reaction, where one element takes the ar of another, leaving the various other alone is called single replacement reaction.

Hence, the correct answer is: single replacement reaction.

PART-2: The reason why aluminum doesn"t react with the potassium nitrate is the potassium is much more reactive than aluminum. It method that that is impossible for the aluminum to break the bond between potassium and nitrate and also takes the ar of potassium. In this case, in unshened way, you can say the potassium nitrate is a happily-together compound, and also their bond cannot be damaged by alumium, due to the fact that aluminum is much less reactive 보다 potassium.


PART-1: In basic words, the half-life is the moment the radioactive sample takes for fifty percent of its atom to decay. In the table, together you deserve to see, the sample at time t = 0 hrs is 186 grams. Now discover the time this radioactive sample will certainly take for half of its grams to decay, i beg your pardon in this situation is 186/2 = 93 grams...

Well, in the table, after time t = 21 hours, 93 grams of radiation sample remains (which is fifty percent of that original/initial amount). Hence, the half life that this radioactive sample is:


PART-2: In the vault part, we have discovered the fifty percent life of the radiation sample, which we shall usage at the finish of this problem. First let us uncover out variety of half-lives that passes when 320 g that the sample will decay to 2.5 g.

Use the complying with formula:

--- (A)


n = number of half lives the passes = ?

= initial massive of the sample = 320 g

= massive left after ~ decaying (or after t quantity of time) = 2.5 g

Plug the values in equation (A):


In Part-1, us have found the half life that this radioactive substance is 21. Now to obtain the time to decay t, all you should do is to main point n through the fifty percent life (21 hours).


Hence, it will certainly take 147 hrs to degeneration to 2.5 grams from 320 gram.


See explanation


FeCl3 +3 NaOH →3 NaCl + Fe(OH)3

One mole that ferric chloride reaction with three moles of salt hydroxide come yield 3 moles of sodium chloride and also one mole the ferric hydroxide. The reaction show the law of conservation of mass since the full mass of reactants equates to the complete masses of commodities formed.

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b) neutralization reaction

c) lead is reduced than zinc in the activity collection of metals however calcium is higher than zinc hence zinc can not displace calcium yet it have the right to displace lead.