All categories

3 years ago

Why do we have to balance chemical equations

Chemistry

1 answer:

Lunna [17]3 years ago

7 0

Answer:

Chemical equations are balanced to comply with the law of conservation of mass.

Explanation:

Law of conservation of mass states that matter cannot be either created or destroyed.

A skeleton chemical equation shows the reactants and products of a chemical reaction without taking into account the real proportion in which the reactants combine and the products are obtained.

An example of a skeleton reaction is the combustion of methane:

CH₄ + O₂ → CO₂ + H₂O

Such as that equation is shown, there are four atoms of hydrogen in the reactants but only 2 atoms of hydrogen in the products. Also, there are 2 atoms of oxygen in the reactants but three atoms of oxygen in the products. This seems to show that some atoms of hydrogen have been destroyed and some atoms of oxygen have been created. This is impossible as it is against the law of conservation of matter.

Then, to show a real situation, the chemical equation of combustion must be balanced, adjusting the coefficients. This is the balanced chemical equation:

CH₄ + 2O₂ → CO₂ + 2H₂O

Now you see that the number of atoms of each matter is conserved: the number of carbon atoms in each side is 1, the number of atoms of hydrogen in each side is 4, and the number of atoms of oxygen in each side is 4. Thus, by balancing the chemical equation, the law of conservation of mass is not violated.

You might be interested in

The molecule NH3 contains all single bonds. true false

dsp73

<h3>Answer;</h3>

True

<h3>Explanation;</h3>

The molecule NH3 contains all single bonds.
NH3 has a three single covalent bond among its nitrogen and hydrogen atoms,because one valence electron of each of three atom of hydrogen is shared with three electron.
There are three covalent bonds are in NH3 . Each hydrogen make a single bond with nitrogen and there is also a pair of electron which is unpaired from nitrogen.

8 0

3 years ago

Read 2 more answers

Which of the following reactions have a positive ΔSrxn? Check all that apply.

PolarNik [594]

Answer:

The reactions that have a positive ΔS rxn are the first and the fourth choices:

2A(g) + B(s) → 3C(g)

2A(g) + 2B(g) → 5C(g)

Explanation:

ΔS rxn is the change of entropy of the chemical reaction.

ΔS rxn = S after reaction - S before reaction.

Therefore, a positive ΔS rxn means that the entropy after the reaction is greater than the entropy before the reaction.

You may use some assumptions to predict whether a reaction will lead an increase or decrease of the entropy.

First, assume that all the non-shown conditions, such as temperature and pressure, are constant.

Under that assumption, and from the meaning of entropy as a measure of the disorder or randomness of a system you can predict the sign of the change of entropy.

2A(g) + B(s) → 3C(g)

1) The solid compounds, B(s) in this case, are very ordered and so they have low entropy.

2) Gas molecules are highly disordered (scattered), and the greater the number of molecules of the gas the larger the entropy, S).

Hence, since the product side shows 3 gas molecules and the reactant side shows 2 gas molecules and 1 solid molecule, you predict that the products have a larger entropy than the reactants, meaning an increase in entropy: ΔS rxn is positive.

2A(g) + B(g) → C(g)

Using the same reasoning, 3 gas molecules in the reactant side have more entropy than 1 molecule in the product side, and so the reaction leads to a decrease in the entropy: ΔS rxn is negative

A(g) + B(g) → C(g)

Again, 2 gas molecules in the reactant side have more entropy than 1 molecule in the product side, and so the reaction leads to a decrease in the entropy: ΔS rxn is negative

2A(g) + 2B(g) → 5C(g)

With the same reasoing, 5 molecules in the product side, lets you predict that will have more entropy than 4 molecules in the reactant side, and, the entropy will increase: ΔS rxn is positive.

6 0

3 years ago

The wind causes this wind turbine to spin, creating electricity. The moving blades are evidence of A) solar power. B) work being

timama [110]

They answer is (C) Potential Energy

5 0

2 years ago

List three examples of high energy waves that are harmful to living things:

lord [1]

UV rays, gamma rays, and x rays
Hope this help

5 0

3 years ago

Why are noble metals for example Rhodium, Palladium, Platinum, and Iridium largely used in chemical manufacturing as heterogeneo

Elanso [62]

They are also called the noble gases or inert gases. They are virtually unreactive towards other elements or compounds. They are found in trace amounts in the atmosphere. Their elemental form at room temperature is colorless, odorless and monatomic gases. They also have full octet of eight valence electrons in their highest orbitals so they have a very little tendency to gain or lose electrons to form ions or share electrons with other elements in covalent bonds.

4 0

3 years ago