"which of these nitrogen compounds is in the most reduced state?"

What is the mass of 2.15 liters of N2 gas at STP?

devlian [24]

Answer:

2.68g

Explanation:

Given parameters:

Volume of gas at STP = 2.15L

Unkown:

Mass of Nitrogen N₂ gas at STP = ?

Solution

To find the mass of the gas at STP, we use the mole concept approach.

In using the mole approach we follow the following procedures:

1. Find the number of moles of gas at STP using the relationship below:

Number of moles = $\frac{volume occupied}{22.4dm^{3} mol^{-1} }$

Note: 1L = 1dm³

2. Then using the mole and mass relationship, we can find the mass of the gas using the equation below:

Mass = number of moles x molar mass

Workings

1. Number of moles of N₂ = $\frac{2.15}{22.4}$

Number of moles of N₂ = 0.096mole

2. Given that the atomic mass of N = 14g

Molar mass of N₂ = 2 x 14 = 28gmol⁻¹

Mass = 0.096mol x 28gmol⁻¹ = 2.68g

6 0

1 year ago

A reaction container holds 5.77 g of P4 and 5.77 g of O2.

Dvinal [7]

Answer:

a) O2 is the limiting reactant

b) 5.75 grams P4O10

c) 5.79 grams P4O6

Explanation:

Step 1: Data given

Mass of P4 = 5.77 grams

Mass of O2 = 5.77 grams

Molar mass of P4 = 123.90 g/mol

Molar mass O2 = 32.0 g/mol

Step 2: The balanced equation

P4 + 3O2 → P4O6

Step 3: Calculate moles of P4

Moles P4 = mass P4 / molar mass P4

Moles P4 = 5.77 grams / 123.90 g/mol

Moles P4 = 0.0466 moles

Step 4: Calculate moles O2

Moles O2 = mass O2 / molar mass O2

Moles O2 = 5.77 grams / 32.0 g/mol

Moles O2 = 0.1803 moles

Step 5: Calculate limiting reactant

P4 is the limiting reactant in this reaction. It will completely be consumed (0.0466 moles). O2 is in excess, there will react 3*0.0466 = 0.1398 moles

There will remain 0.1803 - 0.1398 = 0.0405 moles O2

Step 6: Calculate the amount of P4O6

For 1 mol P4 we'll have 1 mol P4O6

For 0.0466 moles P4 we'll have 0.0466 moles P4O6

Step 7: The balanced equatio

P4O6 + 2O2 → P4O10

We have 0.0466 moles P4O6 and 0.0405 moles O2

Step 8: Calculate the limiting reactant

For 1 mol P4O6 we need 2 moles O2 to produce 1 mol P4O10

O2 is the limiting reactant. It will completely be consumed (0.0405 moles)

P4O6 is in excess. There will react 0.0405/2 = 0.02025 moles

There will remain 0.0466 - 0.02025 = 0.02635 moles P4O6

This is 0.02635 * 219.88 g/mol = 5.79 grams P4O6

Step 9: Calculate moles and mass of P4O10

For 1 mol P4O6 we need 2 moles O2 to produce 1 mol P4O10

For 0.0405 moles O2 we'll have 0.02025 moles P4O10

This is 0.02025 * 283.89 g/mol = 5.75 grams P4O10

3 0

2 years ago

The mole fraction of A (XA ) in the vapor phase of a mixture of two liquids is 0.24 and the sum of the partial pressures is 740

Yakvenalex [24]

Answer:

Mole fraction of B is 0.76

Explanation:

The pressure of a mixture of gases using vapor pressure and mole fraction of each gas is:

P = P°aₓXa + P°bₓXb + ... + P°nₓXn

<em>Where P is pressure of the system, P° is vapor pressure of pure gas and X is its mole fraction.</em>

In the problem, the pressure of the mixture of two gases is 740torr, mol fraction of A is 0.24 and vapor pressure of B is 800torr, that is:

740torr = P°aₓ0.24 + 800torrₓXb

Also, the sum of mole fractions for each of the compounds in the mixture is 1, that is:

1 = Xa + Xb

As Xa = 0.24

1 = 0.24 + Xb

1-0.24 = Xb

0.76 = Xb

<em>Mole fraction of B is 0.76</em>

4 0

1 year ago

Cobalt-60 is a radioactive isotope used to treat cancers. A gamma ray emitted by this isotope has an energy of 1.33 MeV (million

Natalka [10]

Answer:

E = 1.33 MeV = 2.13 x $10^{-13}$ J

v = wavelength = E / h = 2.13 x $10^{-13}$ / 6.626 x $10^{-34}$ = 3.2 x $10^{20}$ m

f = frequency = c / 3.2 x $10^{20}$ m = 3 x $10^{8}$ / 3.2 x $10^{20}$ = 9.375 x $10^{-13}$ Hz

5 0

2 years ago

Which element can form a chloride with a general formula of MCl2 or MCl3

zhannawk [14.2K]

Oxidation state number can be used to determine the unknown element in these two compounds. They are used to determine how many electrons are given, taken or shared to form compounds.

Recall the elementary rules of oxidation numbers.

1. The sum of all oxidation numbers in a neutral compound is zero.
2. Chlorine, bromine, iodine have oxidation number of -1 ( except compounds with fluorine and oxygen)

Let oxidation number of element M be x.
Check rule 2. Chlorine has -1 oxidation number.

Now we write an equation of MCl₂ (neutral compound)
x + (2 * -1)= 0 ⇒ x₁= +2

For MCl₃
x + (3 * -1)= 0 ⇒ x₂= +3

So element has 2 different oxidation number in compounds, +2 and +3.

The element is iron (Fe) since it has +2 and +3 oxidation numbers in the compounds.

You need to learn it by hard. Unfortunately there is not an easier way to work out with these oxidation numbers.

The answer is iron (Fe).

5 0

1 year ago