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3 years ago

PLEASE HELP ASAP!!!

Chemistry

2 answers:

alexdok [17]3 years ago

8 0

Answer:

Answers are bellow.

Explanation:

The element with electron configuration 1s22s22p63s1 belong I A group in the periodic table and it is sodium because it loses one electron.

We have periodic table in attachments.

Sodium is a chemical element with the symbol Na and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 of the periodic table, because it has a single electron in its outer shell, which it readily donates, creating a positively charged ion—the Na+ cation. Its only stable isotope is 23Na.

The free metal does not occur in nature, and must be prepared from compounds.

It is soft metal, reactive and with a low melting point.

AveGali [126]3 years ago

5 0

Answer:

Explanation:

The vertical columns of the periodic table are known as groups, while the horizontal rows of the periodic table are called periods. All the elements that belong to a group have the same valence, and therefore, they have characteristics or properties similar to each other. That is, in each group the elements with the same number of electrons appear in the last occupied level or valence shell. For example, all elements in group 13 contain 3 electrons in their outermost shell.

On the other hand, in each period the elements appear whose last level of their electronic configuration coincides with the number of the period. For example, period 3 includes elements whose outermost electrons are at level 3.

So, in this case the element belongs to period 3 and group 1. When locating it in the periodic table, the element is sodium (Na).

The alkali metals correspond to Group 1 of the Periodic Table. So sodium is an alkali metal. It is characterized by its high reactivity, due to the fact that they form chemical bonds with many types of substances and elements and that they do it easily. This is due to its high electronegativity and the ease of releasing its electron from the outermost layer.

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When 2.00 g of methane are burned in a bomb calorimeter, the change in temperature is 3.08°C. The heat capacity of the calorimet

melisa1 [442]

Answer:

The approximate molar enthalpy of combustion of this substance is -66 kJ/mole.

Explanation:

First we have to calculate the heat gained by the calorimeter.

$q=c\times \Delta T$

where,

q = Heat gained = ?

c = Specific heat = $2.68 kJ/^oC$

ΔT = The change in temperature = 3.08°C

Now put all the given values in the above formula, we get:

$q=2.68 kJ/^oC\times 3.08^oC$

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Now we have to calculate molar enthalpy of combustion of this substance :

$\Delta H_{comb}=-\frac{q}{n}$

where,

$\Delta H_{comb}$ = enthalpy change = ?

q = heat gained = 8.2544kJ

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3 years ago

How many moles of NH3 would be formed from the complete reaction of 16.0 g H2?

natima [27]

Taking into account the reaction stoichiometry, 5.33 moles of NH₃ are formed from the complete reaction of 16 grams of H₂.

<h3>Reaction stoichiometry</h3>

In first place, the balanced reaction is:

N₂ + 3 H₂ → 2 NH₃

By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:

N₂: 1 mole
H₂: 3 moles
NH₃: 2 moles

The molar mass of the compounds is:

N₂: 14 g/mole
H₂: 2 g/mole
NH₃: 17 g/mole

Then, by reaction stoichiometry, the following mass quantities of each compound participate in the reaction:

N₂: 1 mole ×14 g/mole= 14 grams
H₂: 3 moles ×2 g/mole= 6 grams
NH₃: 2 moles ×17 g/mole=34 grams

<h3>Mass of NH₃ formed</h3>

The following rule of three can be applied: if by reaction stoichiometry 6 grams of H₂ form 2 moles of NH₃, 16 grams of H₂ form how many moles of NH₃?

$moles of NH_{3}= \frac{16 grams of H_{2} x2moles of NH_{3}}{6 grams of H_{2}}$

<u><em>moles of NH₃= 5.33 moles</em></u>

Then, 5.33 moles of NH₃ are formed from the complete reaction of 16 grams of H₂.

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