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3 years ago

Using the symbol below/above determine the number of protons, neutrons, and electrons in the element.

Chemistry

1 answer:

malfutka [58]3 years ago

7 0

Hi,
The correct answer is C.
Protons= 50 (because the atomic number of Sn is 50) —> The atomic number always represent the number of protons

Neutrons= 68 (if you want to find the number of neutrons, you need to do: atomic mass (118 in this case) - your number of protons (50)

Electrons= 46 (50 - 4)

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Consider the following reaction at a high temperature. Br2(g) ⇆ 2Br(g) When 1.35 moles of Br2 are put in a 0.780−L flask, 3.60 p

UNO [17]

Answer : The equilibrium constant $K_c$ for the reaction is, 0.1133

Explanation :

First we have to calculate the concentration of $Br_2$ .

$\text{Concentration of }Br_2=\frac{\text{Moles of }Br_2}{\text{Volume of solution}}$

$\text{Concentration of }Br_2=\frac{1.35moles}{0.780L}=1.731M$

Now we have to calculate the dissociated concentration of $Br_2$ .

The balanced equilibrium reaction is,

$Br_2(g)\rightleftharpoons 2Br(aq)$

Initial conc. 1.731 M 0

At eqm. conc. (1.731-x) (2x) M

As we are given,

The percent of dissociation of $Br_2$ = $\alpha$ = 1.2 %

So, the dissociate concentration of $Br_2$ = $C\alpha=1.731M\times \frac{1.2}{100}=0.2077M$

The value of x = 0.2077 M

Now we have to calculate the concentration of $Br_2\text{ and }Br$ at equilibrium.

Concentration of $Br_2$ = 1.731 - x = 1.731 - 0.2077 = 1.5233 M

Concentration of $Br$ = 2x = 2 × 0.2077 = 0.4154 M

Now we have to calculate the equilibrium constant for the reaction.

The expression of equilibrium constant for the reaction will be :

$K_c=\frac{[Br]^2}{[Br_2]}$

Now put all the values in this expression, we get :

$K_c=\frac{(0.4154)^2}{1.5233}=0.1133$

Therefore, the equilibrium constant $K_c$ for the reaction is, 0.1133

7 0

3 years ago

9. A student wished to prepare ethylene gas by dehydration of ethanol at 140oC using sulfuric acid as the dehydrating agent. A l

Arte-miy333 [17]

We have that the the liquid is

C_2H_5OH (ethanol
And at a condition of H_2SO4 as catalyst and temp 170

From the question we are told

A student wished to prepare <em>ethylene </em>gas by <em>dehydration </em>of ethanol at 140oC using sulfuric acid as the <em>dehydrating </em>agent.
A low-boiling liquid was obtained instead of ethylene.
What was the liquid, and how might the reaction conditions be changed to give ethylene

<h3>Ethylene formation</h3>

Generally the equation is

2C_2H_5OH------CH3CH_2O-CH_2CH_3+H_20

Therefore

with ethanol at 140oC

The product is diethyl ethen

The reaction at 170 ethylene will give

C_2H_5OH-------CH_2=CH_2+H_2O( at a condition of H_2SO4 as catalyst and temp 170)

Therefore

The the liquid is

C_2H_5OH (ethanol

For more information on Ethylene visit

brainly.com/question/20117360

8 0

2 years ago

Suppose you will fill a glass with ice cubes. When the ice cubes melt, is the glass still full

goblinko [34]

No. It will not still be full. The reason being is because when it melts, it's almost the same thing as compacting things down into another object (container). Therefore, you will have some room left i the glass. Like, if your trashcan was over-flowing, and you push it down to compact it so you can add more trash. So when the ice melts, it will not be full.

7 0

3 years ago

In the investigation "Comparing the Effects of the Products of Cellular Respiration

Marianna [84]

The solution changed color because the substances are not neutral.

Chemical substances have different concentrations of the hydrogen cation, called PH.

The higher the pH, the more basic the substance, and the lower the more acidic.

Bromothymol blue is a pH indicator that changes its color according to the pH of the substance, yellow for acid, blue for basic and green for neutral.

In the case of the reactions in question, we have the release of CO2 (acid) in combustion and in cellular respiration, changing the color of bromothymol blue to yellow.

Learn more about pH in: brainly.com/question/491373

3 0

2 years ago

An exciton is: A charged particle made of electrons A charged particle made of holes A neutral particle made of an electron and

Alex

Answer:

A neutral particle made of an electron and hole

Explanation:

Exciton

It is the combination of an electron and a hole ( hole refers to the vacancy of an electron ) . And , as both the electron and the hole have the same charge but the polarity is opposite , the combination will lead to a neutral compound , i.e. , Exciton have no charge and so neutral .

It is free to move in the nonmetallic crystal and since it charge less , it is difficult to detect it directly .

7 0

3 years ago