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3 years ago

NEED HELP FAST

Chemistry

1 answer:

Blababa [14]3 years ago

6 0

Answer: 1. Ethylene is a stable molecule with two carbon atoms connected by a double bond. Polyethylene is made by the reaction of multiple ethylene molecules in the presence of a catalyst.

2. The term “plastics” includes materials composed of various elements such as carbon, hydrogen, oxygen, nitrogen, chlorine, and sulfur.

3. Polyethylene (PE) is made by the reaction of multiple ethylene molecules in the presence of catalysts to break the double bond and connect the carbon atoms into a chain . The longer the chain, the higher the molecular weight. Polymers can have molecular weights in the millions.

Explanation:

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Consider the following equilibrium:

Ainat [17]

Answer: The equation which is wrong is $K_p=K_c(RT)^{-5}$

Explanation:

For the given reaction:

$4Fe(s)+3O_2(g)\rightarrow 2Fe_2O_3(s)$

The expression for $K_c\text{ and }K_p$ is given by:

$K_c=\frac{1}{[O_2]^3}$

$K_p=\frac{1}{[O_2]^3}$

The concentration of solids are taken to be 1, only concentration of gases and liquid states are taken. The pressure of only gases are taken.

Relationship between $K_p\text{ and }K_c$ is given by the expression:

$K_p=K_c\times (RT)^{\Delta n_g}$

where,

$\Delta n_g$ = number of moles of gaseous products - number of moles of gaseous reactants

R = gas constant

T= temperature

For the above reaction,

$\Delta n_g$ = number of moles of gaseous products - number of moles of gaseous reactants = 0 - 3 = -3

Hence, the expression for $K_p$ is:

$K_p=K_c\times (RT)^{-3}$

Therefore, the equation which is wrong is $K_p=K_c(RT)^{-5}$

7 0

3 years ago

A compound is formed when 9.03 g

NikAS [45]

The percent composition of this compound :

Mg = 72.182%

N = 27.818%

<h3>Further explanation</h3>

Given

9.03 g Mg

3.48 g N

Required

The percent composition

Solution

Proust stated the Comparative Law that compounds are formed from elements with the same Mass Comparison so that the compound has a fixed composition of elements

Total mass of the compound :

= 9.03 g + 3.48 g

= 12.51 g

The percent composition :

Mg : 9.03/ 12.51 g x 100% = 72.182%

N : 3.48 / 12.51 g x 100% = 27.818%

3 0

3 years ago

Given 3.4 grams of x compound with a molar mass of 85 g and 4.2 grams of y compound with a molar mass of 48 g How much of compou

Ulleksa [173]

Answer:

$4.36~g~XY$

Explanation:

In this case, we can start with the reaction:

$2X + Y_2~->~2XY$

If we check the reaction, we will have 2 X and Y atoms on both sides. So, the reaction is balanced. Now, the problem give to us two amounts of reagents. Therefore, we have to find the limiting reagent. The first step then is to find the moles of each compound using the molar mass:

$3.4~g~X\frac{1~mol~X}{85~g~X}=0.04~mol~X$

$4.2~g~Y_2\frac{1~mol~Y_2}{48~g~Y_2}=0.0875~mol~Y_2$

Now, we can divide by the coefficient of each compound (given by the balanced reaction):

$\frac{0.04~mol~X}{1}=~0.04$

$\frac{0.0875~mol~Y_2}{2}=0.04375$

The smallest value is for "X", therefore this is our limiting reagent. Now, if we use the molar ratio between "X" and "XY" we can calculate the moles of XY, so:

$0.04~mol~X\frac{2~mol~XY}{2~mol~X}=0.04~mol~XY$

Finally, with the molar mass of "XY" we can calculate the grams. Now, we know that 1 mol X = 85 g X and 1 mol $Y_2$ = 48 g $Y_2$ (therefore 1 mol Y = 24 g Y). With this in mind the molar mass of XY would be 85+24 = 109 g/mol. With this in mind:

$0.04~mol~XY\frac{109~g~XY}{1~mol~XY}=4.36~g~XY$

I hope it helps!

6 0

3 years ago

Why does a hot air balloon rise when the air inside it is heated

Nastasia [14]

hot air rises up in the balloon and lifts the balloon up

7 0

3 years ago

A 1.00 liter solution contains 0.31 M hydrocyanic acid and 0.40 M sodium cyanide. If 0.100 moles of barium hydroxide are added t

andriy [413]

Explanation:

acid --> HCN

base --> KCN

now

another base NaOH is added

we know that

base will react with an acid

OH- + HCN ---> CN- + H20

we can see that

HCN is used up , so number of moles of HCN will decrease

CN- is being formed , so number of moles of CN- will increase.

A false

B false

C false

D true

E false

6 0

3 years ago