All categories

3 years ago

When iron reacts with oxygen, it forms iron oxide, or rust.

Chemistry

1 answer:

Feliz [49]3 years ago

3 0

Answer:

Mass of iron oxide: 79.85 g

Explanation:

Given data:

Mass of iron = 112 g

Mass of O₂ = 24 g

Mass of iron oxide formed = ?

Solution:

4Fe + 3O₂ → 2Fe₂O₃

Number of moles of Fe:

Number of moles = mass/ molar mass

Number of moles = 112 g/ 55.85 g/mol

Number of moles = 2 mol

Number of moles of O₂:

Number of moles = mass/ molar mass

Number of moles = 24 g/ 32 g/mol

Number of moles = 0.75 mol

Now we will compare the moles of oxygen and iron with iron oxide.

Fe : Fe₂O₃

4 : 2

2 : 2/4×2 = 1

O₂ : Fe₂O₃

3 : 2

0.75 : 2/3×0.75 = 0.5

The number of moles of iron oxide formed by oxygen are less thus it will be limiting reactant.

Mass of iron oxide:

Mass = number of moles × molar mass

Mass = 0.5 mol × 159.69 g/mol

Mass = 79.85 g

You might be interested in

How do I solve the following word problem: The half-life of Phosphorus - 32 is 14.3 days. It is used to study a plant's use of f

BaLLatris [955]

Half life is the time that it takes for half of the original value of some amount of a radioactive element to decay.

We have the following equation representing the half-life decay:

$A=A_o\times2^{(-\frac{t}{t_{half}})_{}_{}}$

A is the resulting amount after t time

Ao is the initial amount = 50 mg

t= Elapsed time

t half is the half-life of the substance = 14.3 days

We replace the know values into the equation to have an exponential decay function for a 50mg sample

$A=\text{ 50 }\times2^{\frac{-t}{14.3}}$

That would be the answer for a)

To know the P-32 remaining after 84 days we have to replace this value in the equation:

$\begin{gathered} A=\text{ 50 }\times2^{\frac{-84}{14.3}} \\ A=0.85\text{ mg} \end{gathered}$

So, after 84 days the P-32 remaining will be 0.85 mg

4 0

1 year ago

A brick has a mass of and the Earth has a mass of . Use this information to answer the questions below. Be sure your answers hav

weeeeeb [17]

The given question is incomplete. The complete question is:

A brick has a mass of 4.0 kg and the earth has a mass of $6.0\times 10^{27}g$ Use this information to answer the questions below. Be sure your answers have the correct number of significant digits. What is the mass of 1 mole of bricks? Round your answer to 2 significant digits. How many moles of bricks have a mass equal to the mass of the Earth? Round your answer to 2 significant digits.

Answer: The mass of 1 mole of bricks is $2.4\times 10^{27}g$

2.5 moles of bricks have a mass equal to the mass of the Earth

Explanation:

According to avogadro's law, 1 mole of every substance weighs equal to its molecular mass and contains avogadro's number $6.023\times 10^{23}$ of particles.

Mass of 1 brick = 4.0 kg = 4000 g (1kg=1000g)

Thus mass of 1 mole of brick or $6.023\times 10^{23}$ bricks will be = $\frac{4000g}{1}\times 6.023\times 10^{23}=2.4\times 10^{27}g$

The mass of 1 mole of bricks is $2.4\times 10^{27}g$

Now $2.4\times 10^{27}g$ will correspond to = 1 mole of bricks

$6.0\times 10^{27}g$ will correspond to = $\frac{1}{2.4\times 10^{27}}\times 6.0\times 10^{27}=2.5moles$

2.5 moles of bricks have a mass equal to the mass of the Earth

5 0

2 years ago

You are currently in a stable orbit 9000 km (1km=1000m) from the center of planet Proxima Centauri B.

pantera1 [17]

Explanation:

bro this question looks like Astrophysics

6 0

3 years ago

At standard temperature and pressure, the element with the chemical symbol _______ is a liquid.

Bezzdna [24]

The only liquid elements at standard temperature and pressure are bromine (Br) and mercury (Hg). Although, elements caesium (Cs), rubidium (Rb), Francium (Fr) and Gallium (Ga) become liquid at or just above room temperature.

5 0

3 years ago

Who discovered that a dense positively charged atomic nucleus is at the core of every atom

Inessa [10]

Answer:

Answer should be Ernest Rutherford

Explanation:

He was a New Zealand-born British physicist who came to be known as the father of nuclear physics.

4 0

3 years ago