How many moles are in 155 grams of aluminum

Identify the compound with the highest standard free energy of formation. identify the compound with the highest standard free e

Anestetic [448]

The compound with the highest standard free energy of formation is O3(g)

7 0

3 years ago

*

Natasha_Volkova [10]

to be honestl id ldm

4 0

2 years ago

Could someone please care to explain what the answer is

polet [3.4K]

Calculate the percentage composition of Ca(MnO4)2.

<u>Firstly, we see how many atoms are there for each element in the formula</u>.

Ca= 1 atom

Mn= 2 atoms

O= 8 atoms

<u>Next, we are going to consult our periodic table for the atomic mass of each element.</u>

Ca= 40

Mn= 55

O= 16

Then, we have to find the molar mass for the compound..

Here is the formula for calculating molar mass of an element:

Molar Mass= ( no. of atoms of the element × atomic mass of the element)

Now, we have to calculate the atomic mass of the compound. So using the molar mass formula for an element, we calculate the molar mass for each element then we sum up their molar masses to get the compounds molar mass.

Molar mass (Ca)= 1× 40

(Ca)= 40

Molar mass (Mn)=2×55

(Mn)= 110

Molar mass (O)= 8×16

(O)= 128

Now: Molar mass( compound)= (Ca)+(Mn)+(O)

= 40+ 110 128

= 278

This is everything we need to calculate our percentage composition for each element..

* The example says to find the percentage composition for Ca. So we only find for Ca, Which is already done using the formula and the answer is 14.39%.

To prove that your answer is correct, find the percentage composition for Mn and O as well. Then you add up their percentage compositions.

If you do and you get 100 as your answer, then your percentage compositions are correct.

Why don't you try finding the percentage composition for Mn and O, then add up all the three percentage compositions. If you 100 as their sum, then your percentage composition for each of the elements are correct.

6 0

2 years ago

Elements donate 2 electron to produce a cation with a 2+ charge

hammer [34]

Answer: alkaline earth metals (group-IIA)

Explanation:

The element which donates the electron is known as electropositive element and forms a positively charged ion called as cation. The element which accepts the electrons is known as electronegative element and forms a negatively charged ion called as anion.

Alkaline earth metals donate 2 valence electrons to acquire noble gas configuration.

For example: Berrylium is the first alkaline earth metal with atomic number of 4 and thus has 4 electrons

Electronic configuration of berrylium:

$[Be]:4:1s^22s^2$

Berrylium atom will loose two electrons to gain noble gas configuration and form berrylium cation with +2 charge.

$[Be^{2+}]:2:1s^2$

Thus Elements donate 2 electron to produce a cation with a 2+ charge are alkaline earth metals.

5 0

2 years ago

Which of these substances would have the highest ph?

maw [93]

Whichever one has the smallest amount of H+ Ions.

6 0

3 years ago