What can be said about an exothermic reaction with a negative entropy change?.

Calculate the number of atoms in 112 g of iron.

mr_godi [17]

Answer:

1 mole of iron (Fe) = 56 g (molar mass)

Since 56 g of iron = 1 mol.

Therefore, 112 g of iron= 1/ 56 ×112 mol = 2 mol.

Explanation:

8 0

3 years ago

How do chemists use systems and order in their work?

san4es73 [151]

Answer:

5 point) Chemists used systems and order because they study the basic unit of all forms of matter, which is the atom . However, there are several different kinds of atoms, called elements . Chemists organize these elements using the periodic table .

Explanation:

3 0

2 years ago

Question 2 Describe the energy in coal and the way in which it’s converted to electrical energy.

Scilla [17]

Answer:

Its rich carbon content gives coal most of its energy content. When coal is burned in the presence of air or oxygen, heat energy is released. This energy can then be converted to other forms of useful energy. Coal-fired plants produce electricity by burning coal in a boiler to produce steam. The steam produced, under tremendous pressure, flows into a turbine, which spins a generator to create electricity.

Hope this helps! :)

7 0

2 years ago

The following chemical reactants produce the ester ethyl ethanoate (C4H8O2): C2H6O + CH3COOH What type of reaction occurs to mak

nydimaria [60]

Answer:

Esterification reaction

Explanation:

An esterification reaction is an organic reaction involving an organic acid and an alkanol to give an ester or an ethanoate and water

Like the name suggests, an ester is the product formed in an esterification reaction alongside water. It is like a neutralization reaction but this time it solely contains organic molecules. These molecules react with each other to give rise to another organic molecule which is a member of a different homologous series.

Practically, to form ethyl ethanoate, ethanoic acid react with ethanol in the presence of concentrated sulphuric acid which catalyses the reaction.

8 0

3 years ago

Which statements are true concerning elements in the same group of the periodic table? Select all that apply.

Tatiana [17]

The statements A and F are true concerning elements in the same group of the periodic table.

To select all that apply, we need to evaluate each statement.

A. They have similar periodic properties.

This statement is true. All the elements in the same group will have similar chemical and physical properties due to the electron configuration of their outer shell. For example, the alkali metals group (Li, Na, K, Rb, Cs, and Fr), has a valence electron configuration of s¹ (in the outer shell), which gives them the tendency to react vigorously with water, as well as other properties.

B. They are all metals or nonmetals, but not both.

This is false. If we take a look at the p-block of the periodic table, we can see that the groups in this block are conformed by nonmetals, metals, and metalloids. For example, the icosagens group is formed by metalloids (B) and metals (Al, Ga, In, Tl).

C. They are either all solids or all liquids or all gases.

This is false. In some groups, all the elements are solids (alkaline earth metals) or gases (group of noble gases), but in others, the groups are conformed by gases with solids (pnictogens group) or by gases with liquids (halogens group).

D. They have the same number of shells of electrons.

This is false. In a group, the number of shells increases from top to bottom in the periodic table. For example, the electron configuration of the elements in the alkali metals is:

H: 1s¹
Li: [He]2s¹
Na: [Ne]3s¹
K: [Ar]4s¹
Rb: [Kr]5s¹
Cs: [Xe]6s¹
Fr: [Rn]7s¹

We can see that hydrogen has 1 shell and Cs has 6 shells.

E. They have the same number of inner core electrons.

This is false. As we said at point D, the number of shells increases from top to bottom in a group, so the number of inner core electrons also increases in this order. For example, in the alkaline earth metals group, the electron configuration of the elements is:

Be: [He]2s²
Mg: [Ne]3s²
Ca: [Ar]4s²
Sr: [Kr]5s²
Ba: [Xe]6s²
Ra: [Rn]7s²

As we can see, the number of inner shells increases from Be ([He]) to Ra ([Rn]).

F. They have the same outer shell electron configuration.

This is true. As we said at point A, the elements in the same group will have the same electron configuration of the outer shell (valence electron configuration). At points D and E, we can see that the valence electron configuration is the same for all the elements in the groups.

Therefore, statements A and F are true.

You can find more about the periodic table here: brainly.com/question/4287157?referrer=searchResults

I hope it helps you!

6 0

3 years ago