Plz help with number 4

How many molecules are there in 79g of Fe2O3? how many atoms is thi

Nookie1986 [14]

Molar mass of iron(III) oxide is 160g/mol

160g ----------- of iron(III) oxide is ---------------- 6.02*10²³molecules
79g ----------- of iron(III) oxide is ---------------- x

x = [6.02*10²³*79g]/160g ≈ 2.97*10²³ molecules

7 0

3 years ago

How many moles are represented by 3.01 - 1023 helium atoms?

Pavlova-9 [17]

Answer:

0.5 mol

Explanation:

Given data:

Number of atoms of He = 3.01 ×10²³

Number of moles = ?

Solution:

Avogadro number:

It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.

The number 6.02 × 10²³ is called Avogadro number.

1 mole = 6.02 × 10²³ atoms

3.01 ×10²³ atoms × 1 mol / 6.02 × 10²³ atoms

0.5 mol

7 0

3 years ago

Why is modern periodic table better than Mendeleev's periodic table?

ladessa [460]

Answer:

because mariah carey wrote it

Explanation:

she also made a song out of it!

3 0

2 years ago

Which of the following describes carbon dioxide? O Has polar covalent bonds and is a polar molecule O Has non-polar covalent bon

OLga [1]

Answer: Option "Has polar bonds and is a non-polar molecule" is the correct answer.

Explanation:

A covalent compound is defined as the compound in which there will be sharing of electrons between the combining atoms.

An ionic compound is defined as the compound in which there will be transfer of electrons from one atom to another.

A non-polar covalent compound is defined as the compound in which there will be equal sharing of electrons between the combining atoms.

For example, a chlorine atom has 7 valence electrons.

So, when a chlorine atom chemically combines with another chlorine atom then there occurs equal sharing of electrons.

Hence, molecule $Cl_{2}$ is formed which is non-polar covalent compound in nature with non-polar covalent bond.

A polar covalent bond is defined as the bond in which there will be unequal sharing of electrons between the combining atoms.

For example, a carbon atom has 4 valence electrons and an oxygen atom has 6 valence electrons.

To complete their octet a carbon atom needs 4 more electrons and an oxygen atom needs 2 more electrons.

And, when one carbon and two oxygen atoms chemically combine together then there occurs unequal sharing of electrons.

Hence, a polar covalent compound $CO_{2}$ is formed.

Since, oxygen is more electronegative than carbon atom. Hence, dipoles in the linear carbon dioxide molecules will cancel out each other.

Therefore, a carbon dioxide molecule is non-polar compound that has polar covalent bonds.

Thus, we can conclude that the statement, has polar bonds and is a non-polar molecule, correctly describes carbon dioxide.

8 0

3 years ago

A potato gun beautifully illustrates Law. As you decrease the volume of the air in between two pieces of potato, the

kati45 [8]

Answer: The law that illustrates this is Boyle's Law

Explanation:

Boyle's law: This law states that pressure of the gas is inversely proportional to the volume of the gas at constant temperature and number of moles.

Mathematically,

$P\propto \frac{1}{V}$ (at constant temperature and number of moles)

Charles' law: This law states that volume of the gas is directly proportional to the temperature of the gas at constant pressure and number of moles.

Mathematically,

$V\propto T$ (at constant pressure and number of moles)

Avogadro's law: This law states that volume of the gas is directly proportional to the number of moles of the gas at constant pressure and temperature.

Mathematically,

$V\propto n$ (at constant pressure and temperature)

So, when the volume of the air in the gun decreases, the pressure is increased. The inverse relationship between the volume and pressure of the gas is very well illustrated by Boyle's Law.

Hence, the law that illustrates this is Boyle's Law

8 0

4 years ago