Determine whether each statement is a description of a physical property or a chemical property.

Hydrogen gas and fluorine gas will react to form hydrogen fluoride gas. What is the standard free energy change for this reactio

Marta_Voda [28]

Answer:

$\Delta G=-541.4kJ/mol$

Explanation:

Hello there!

In this case, according to the given information, it turns out firstly necessary to write out the described chemical reaction as shown below:

$H_2+F_2\rightarrow 2HF$

Now, we set up the expression for the calculation of the standard free energy change, considering the free energy of formation of each species, specially those of H2 and F2 which are both 0 because they are pure elements:

$\Delta G=2\Delta G_f^{HF}-(\Delta G_f^{H_2}+\Delta G_f^{F_2})\\\\\Delta G=2*-270.70kJ/mol-(0kJ/mol+0kJ/mol)\\\\\Delta G=-541.4kJ/mol$

Regards!

4 0

2 years ago

What mineral has the least hardness according to the scale?

kenny6666 [7]

The softest mineral in the Mohs Hardness Scale is talc.
Talc is often used in baby powder and corn starch, among other things. Talc cleaves into thin sheets, and it is held together only by van de Waals bonds, which allows these sheets to slip past each other. This gives the mineral its softness and it is often valued as a high-temperature lubricant.

7 0

3 years ago

What does the roman numeral stand for in copper(1) oxide should it not be copper(II) oxide

photoshop1234 [79]

Answer:

The roman numeral in copper(I) oxide indicates that the oxidation number of copper in the compound is 1.

Explanation:

Roman numeral is used to indicate the oxidation number of an element in a compound.

The roman numeral in copper(I) oxide indicates that the oxidation number of copper in the compound is 1.

This can be seen from the following illustration:

copper(I) oxide => Cu₂O

Oxidation number of O = –2

Oxidation number of Cu₂O = 0

Oxidation number of Cu =?

Cu₂O = 0

2Cu + O = 0

2Cu – 2 = 0

Collect like terms

2Cu = 0 + 2

2Cu = 2

Divide both side by 2

Cu = 2/2

Cu = 1

Thus, we can see that the oxidation number of Cu in Cu₂O is 1. Hence the name of Cu₂O is copper(I) oxide indicating that the oxidation number of of copper (Cu) in the compound is 1.

For copper(II) oxide, we shall determine the oxidation number of Cu. This can be obtained as follow:

copper(II) oxide, CuO => CuO

Oxidation number of O = –2

Oxidation number of CuO = 0

Oxidation number of Cu =?

CuO = 0

Cu + O = 0

Cu – 2 = 0

Collect like terms

Cu = 0 + 2

Cu = 2

Thus, the oxidation number of Cu in CuO is 2. Hence the name of CuO is copper(II) oxide indicating that the oxidation number of of copper (Cu) in the compound is 2.

From the above illustrations,

We can see that the roman numeral in both copper(I) oxide, Cu₂O and copper(II) oxide, CuO are different because the oxidation number of Cu in both cases are different.

3 0

3 years ago

What protects the plant embryo?

Pani-rosa [81]

How do seed plants protect their embryos?
Reptilian embryos are protected from desiccation by a leathery shell. Similarly, sporophytes of both gymnosperms and angiosperms protect embryos within, and they also protect male gametophytes against desiccation using .....

5 0

3 years ago

2. Why does the CDC recommend hand sanitizers with at least 60% alcohol?! I

choli [55]

Answer:

Here's it:

Explanation:

Germs are everywhere! They can get onto hands and items we touch during daily activities and make us sick. Cleaning hands at key times with soap and water or hand sanitizer that contains at least 60% alcohol is one of the most important steps you can take to avoid getting sick and spreading germs to those around you.

There are important differences between washing hands with soap and water and using hand sanitizer. Soap and water work to remove all types of germs from hands, while sanitizer acts by killing certain germs on the skin. Although alcohol-based hand sanitizers can quickly reduce the number of germs in many situations, they should be used in the right situations.

3 0

2 years ago