A double colvalent bond involves two atoms sharing two electrons. True or false?

1. Pewien tlenek azotu o masie cząsteczkowej 108 u zawiera 74,07% tlenu. Wykonaj stosowne obliczenia i napisz wzór sumaryczny te

love history [14]

Answer:

1. Stąd empiryczny wzór substancji to N₂O₅

2. W związku z tym ilość w gramach chlorku sodu NaCl is 114,4 g.

Explanation:

1. Mamy tutaj;

Masa molowa tlenku azotu = 108u

Masa azotu = 14,0067u

Masa tlenu = 15,999 u

74,07% masy tlenku azotu to tlen

Dlatego masa obecnego tlenu = 108 × 74,07 / 100 = 79,9956 u

Masa obecnego azotu = 108 - 79,9956 = 28,0044u

Liczba moli tlenu = 79,9956 / 15,999 = 5,00003 ≈ 5

Liczba moli azotu = 28,0044 / 14,0067 = 1,99935 ≈ 2

Stąd empiryczny wzór substancji to N₂O₅.

2. Kiedy sód reaguje z chlorem, mamy;

2Na (s) + Cl₂ (g) → 2NaCl (s)

Dlatego 2 mole sodu Na reaguje z 1 molem chloru gazowego Cl₂, z wytworzeniem 2 moli chlorku sodu NaCl

W związku z tym 1 mol sodu Na reaguje z 1/2 molem chloru gazowego Cl₂ z wytworzeniem 1 mola chlorku sodu NaCl

Masa Na obecnego w reakcji = 45 g

Masa molowa sodu = 22,989769u

Liczbę moli sodu w 45 g sodu podano w następujący sposób;

$Liczba \, \, moli \, \, Na= \frac{Mass \, of \, Na}{Molowy \, masa \, z \, Na} = \frac{45}{22.989769} = 1.96 \, mole$

Z czego 1,96 moli sodu Na reaguje z 1/2 × 1,96 mola chloru gazowego Cl₂ z wytworzeniem 1,96 mola chlorku sodu NaCl

Masa molowa NaCl = 58,44 g / mol

Dlatego masa NaCl = liczba moli NaCl × masa molowa NaCl

Masa NaCl = 1,96 × 58,44 = 114,39001 g ≈ 114,4 g

W związku z tym ilość w gramach chlorku sodu NaCl = 114,4 g.

4 0

3 years ago

In the article, Invasion of the Periodical Cicadas, why do scienctists believe that cicadas only reproduce every 13 or 17 years?

frez [133]

Hi, you've asked an incomplete question. However, I assumed you are referring to the article found on the Scientific American website.

Explanation:

<em>Remember,</em> according to that article we are told that scientists notice that these insects have a long nymphal (immature form before becoming adults) stage, one that can last up to 13 to 17 years on the ground before they leave the ground looking for mating partners.

Because it is only after mating occurs at this point that their eggs are laid, that is why scientists believe that cicadas only reproduce every 13 or 17 years.

8 0

3 years ago

in heating a kettle of water on an electric stove, 3.34×10^3 J of thermal energy was provided by the element of the stove. yet,

insens350 [35]

Answer:

The percentage efficiency of the electrical element is approximately 82.186%

Explanation:

The given parameters are;

The thermal energy provided by the stove element, $H_{supplied}$ = 3.34 × 10³ J

The amount thermal energy gained by the kettle, $H_{absorbed}$ = 5.95 × 10² J

The percentage efficiency of the electrical element in heating the kettle of water, η%, is given as follows;

$\eta \% = \dfrac{H_{supplied} - H_{absorbed} }{H_{supplied}} \times 100$

Therefore, we get;

$\eta \% = \dfrac{3.34 \times 10^3 - 5.95 \times 10^2}{3.34 \times 10^3} \times 100 = \dfrac{549}{668} \times 100 \approx 82.186 \%$

The percentage efficiency of the electrical element, η% ≈ 82.186%.

4 0

3 years ago

What is the relationship between an atom and a molecule?

musickatia [10]

Answer:

Atoms are given a different weight based on the number of protons and neutrons in the nucleus and electrons in the surrounding cloud. The same electromagnetic force that keeps a single atom together can also hold two or more atoms together to form a molecule, while numerous molecules join together to form matter.Apr 25, 2017

Explanation:

4 0

3 years ago

Read 2 more answers

A solution contains 0.140 mol KCl in 2.100 L water. What is the concentration of KCl in g/L?

viva [34]

<h3><u>Answer</u>;</h3>

≈ 4.95 g/L

<h3><u>Explanation;</u></h3>

The molar mass of KCl = 74.5 g/mole

Therefore; 0.140 moles will be equivalent to ;

= 0.140 moles × 74.5 g/mole

= 10.43 g

Concentration in g/L

= mass in g/volume in L

= 10.43/2.1

= 4.9667

4 0

3 years ago