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3 years ago

Why do we need to balance chemical equations?

2 answers:

8 0

So we know the number of moles of each compound. If we need to know the concentration we must know the number of moles that the compounds react with...

GrogVix [38]3 years ago

6 0

The law of conservation of mass states that matter can neither be created nor destroyed, and it just transforms from one medium to another. Therefore, when a chemical reaction occurs, we need to balance the equation to ensure that the number of particles of the reactants are equal to the number of particles of the products.

Consider the following (unbalanced) equation:
H2 + O2 -> H2O
If this is what actually happens, then where is the second atom of Oxygen?

To ensure that stuff like this doesn't happen, we have to balance equations:
2H2 +O2 -> 2H2O

Now if you count the atoms, you have 4 Hydrogen atoms and 2 Oxygen atoms on both sides, and conservation of mass takes place.

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A barium hydroxide solution is prepared by dissolving 2.81 g of Ba(OH)2 in water to make 25.6 mL of solution. What is the concen

chubhunter [2.5K]

The concentration of the solution in units of molarity is 0.64 M and the concentration of the solution in terms of g/mL is 0.10976 g/mL.

<h3>What is the concentration of the solution?</h3>

The measure of the amount of the solute dissolved in the given amount of the solvent or solution is said to be the concentration of the solution.

It is given by the expression,

Concentration of the solution = mass of the solute/total volume of the solution

Units: g/mL

<h3>What is the concentration of the solution in units of molarity?</h3>

The concentration of the solution in units of molarity is given by the expression,

Molarity = (no. of moles of the solute)/(Volume in L)

Units: moles/L

<h3>Calculation:</h3>

It is given that the solute is barium hydroxide - Ba(OH)₂

The mass of Ba(OH)₂ = 2.81 g

When in dissolved in water, the total volume of the solution = 25.6 mL

The molar mass of Ba(OH)₂ = 171.34 g/mol

Then,

No. of moles = (mass of Ba(OH)₂)/(molar mass of Ba(OH)₂)

i.e.,

No. of moles = $\frac{2.81}{171.34}$ = 0.0164 mole

Concentration = mass of the solute/total volume

I.e., C = $\frac{2.81}{25.6}$ = 0.10976 g/mL

Then the concentration of the solution in units of molarity is,

Molarity = (no. of moles)/(Volume of the solution in L)

⇒ Molarity = $\frac{0.0164}{25.6/1000}$ = 0.64 M

Therefore, the concentration of the solution in units of molarity is 0.64 M.

Learn more about molarity here:

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8 0

1 year ago

Many organisms on Earth exhibit similar ____________.

sukhopar [10]

Characteristics is the correct answer!

3 0

2 years ago

Read 2 more answers

If u have 10 moles of C2H2 how many mole of O2 would you need

padilas [110]

Answer:

i dont know04487448700

4 0

2 years ago

What is the name of the movement of the Earth around the Sun as pointed out by letter J.

MAVERICK [17]

it is called the Earth's rotation

3 0

3 years ago

Write a chemical equation representing the first ionization energy for lithium. use e− as the symbol for an electron.

just olya [345]

The chemical equation representing the first ionization energy for lithium is given by;

Li → Li + e-

<h2>Further Explanation; </h2><h3>Ionization energy</h3>

Ionization energy is the energy required to remove outermost electrons from the outermost energy level. Energy is required to remove an electron from an atom.
The closer an electron is to the nucleus the more energy is required, since the electron is more tightly bound to the atom thus making it more difficult to remove, hence higher ionization energy.
Ionization energy increases across the periods and decreases down the group from top to bottom.
Additionally, the ionization energy increases with subsequent removal of a second or a third electron.

<h3>First ionization energy </h3>

This is the energy required to remove the first electron from the outermost energy level of an atom.
Energy needed to remove the second electron to form a divalent cation is called the second ionization energy.

<h3>Trends in ionization energy </h3><h3>1. Down the group(top to bottom)</h3>

Ionization energy decreases down the groups in the periodic table from top to bottom.
It is because as you move down the group the number of energy levels increases making the outermost electrons get further from the nucleus reducing the strength of attraction to the nucleus.
This means less energy will be required compared to an atoms of elements at the top of the groups.

<h3>2. Across the period (left to right)</h3>

Ionization energy increases across the period from left to right.
This can be explained by an increase in nuclear energy as extra protons are added to the nucleus across the period increasing the strength of attraction of electrons to the nucleus.
Consequently, more energy is needed to remove electrons from the nucleus.

Keywords: Ionization energy, periodic table, energy levels, electrons

<h3>Learn more about</h3>

Ionization energy: brainly.com/question/1971327
Trend in ionization energy: brainly.com/question/1971327
First ionization energy: brainly.com/question/1971327

Level: High school

Subject: Chemistry

Topic: Periodic table and chemical families

Sub-topic: Ionization energy

4 0

3 years ago

Read 2 more answers