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4 years ago

Why do we have to balance chemical equations

Chemistry

1 answer:

Lunna [17]4 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.

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Earth orbits the____ in a imaginary plane called______

Montano1993 [528]

Earth orbits the sun in a imaginary plane called ecliptic

8 0

3 years ago

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1.72 moles of NOCI were placed in a 2.50 L reaction chamber

elena-14-01-66 [18.8K]

The equilibrium constant, Kc=0.026

<h3>Further explanation</h3>

Given

1.72 moles of NOCI

1.16 moles of NOCI remained

2.50 L reaction chamber

Reaction

2NOCI(g) = 2NO(g) + Cl2(g).

Required

the equilibrium constant, Kc

Solution

ICE method

2NOCI(g) = 2NO(g) + Cl2(g).

I 1.72

C 0.56 0.56 0.28

E 1.16 0.56 0.28

Molarity at equilibrium :

NOCl :

$\tt \dfrac{1.16}{2.5}=0.464$

NO :

$\tt \dfrac{0.56}{2.5}=0.224$

Cl2 :

$\tt \dfrac{0.28}{2.5}=0.112$

$\tt Kc=\dfrac{[NO]^2[Cl_2]}{[NOCl]^2}\\\\Kc=\dfrac{0.224^2\times 0.112}{0.464^2}=0.026$

4 0

3 years ago

What is the mass of 3.0 x 10^23 atoms of neon

kari74 [83]

Molar mass neon = 20.1797 g/mol

20.1797 g ---------- 6.02x10²³ atoms
? g ------------ 3.0 x 10²³ atoms

mass = 3.0 x 10²³ * 20.1797 / 6.02 x 10²³

mass = 6.054x10²⁴ / 6.02 x 10²³

mass = 10.05 g

hope this helps!

6 0

3 years ago

Read 2 more answers

The (15-35-15) number on a bag of fertilizer is calculated by an outdated method. All modern fertilizers use PO43- as a source o

Alik [6]

The (15-35-15) number on a bag of fertilizer is calculated by an outdated method. Using the knowledge of the old methods, the number of moles of phosphorus found in 10.0 grams of phosphorus is 0.05 mole.

The (15-35-15) number on the bag of fertilizer is used for:

Nitrogen 15 : Phosphorus pentoxide 35: potassium oxide 15

Thus, in a 100-gram bag of fertilizer, there are 35 grams of phosphorus pentoxide P₂O₅.

∴

To determine the number of moles of 10 grams of phosphorus pentoxide in (15-35-15) bag of fertilizer, we have:

$\mathbf{=10 \times \dfrac{35}{100} \ grams \ of \ P_2O_5}$

= 3.5 grams of P₂O₅

Recall that:

$\mathbf{Number of moles = \dfrac{mass}{molar \ mass}}$

the molar mass of P₂O₅ = 142 g/mol

∴

$\mathbf{Number of moles = \dfrac{3.5\ g}{ 142 \ g/mol}}$

$\mathbf{Number of moles = 0.0246 \ mol}$

Provided that 1 mole of P₂O₅ harbors 2 moles of phosphorus;

Then;

The number of phosphorus present in 10.0 grams of (15-35-15) fertilizer is:

= 0.0246 moles × 2

= 0.0492 moles

≅ 0.05 moles

Therefore, we can conclude that the number of moles of phosphorus found in 10.0 grams of (15-35-15) bag of fertilizer is 0.05 moles.

Learn more about phosphorus here:

brainly.com/question/4622631?referrer=searchResults

8 0

3 years ago

Select the statements below that are false and think about why they are not true.

Anna007 [38]

Answer:

a) and d) are false.

Explanation:

a) The second law of thermodynamics states that the entropy of the universe increases in a spon taneous process and remains unchanged in an equilibrium process.

For a spontaneous process:

ΔSuniv = ΔSsys + ΔSsurr > 0

For a spontaneous process, the second law says that ΔSuniv must be greater than zero, but it does not place a restriction on either ΔSsys or ΔSsurr. Thus, it is possible for either ΔSsys or ΔSsurr to be negative, as long as the sum of these two quantities is greater than zero.

d) A reaction that does occur under the given set of conditions is called a spontaneous reaction. We observe spontaneous physical and chemical processes every day, including many of the following examples:

• A waterfall runs downhill, but never up, spontaneously.

• A lump of sugar spontaneously dissolves in a cup of coffee, but dissolved sugar does not spontaneously reappear in its original form.

• Heat flows from a hotter object to a colder one, but the reverse never happens spontaneously.

5 0

3 years ago