Which reaction is used to produce polyethylene from ethylene

In science, we like to develop explanations that we can use to predict the outcome of events and phenomena. Try to develop an ex

Kay [80]

The question is incomplete. The complete question is :

In science, we like to develop explanations that we can use to predict the outcome of events and phenomena. Try to develop an explanation that tells how much NaOH needs to be added to a beaker of HCl to cause the color to change. Your explanation can be something like: The color change will occur when [some amount] of NaOH is added because the color change occurs when [some condition]. The goal for your explanation is that it describes the outcome of this example, but can also be used to predict the outcome of other examples of this phenomenon. Here's an example explanation: The color of the solution will change when 40 ml of NaOH is added to a beaker of HCl because the color always changes when 40ml of base is added. Although this explanation works for this example, it probably won't work in examples where the flask contains a different amount of HCl, such as 30ml. Try to make an explanation that accurately predicts the outcome of other versions of this phenomenon.

Solution :

Consider the equation of the reaction between NaOH and $HCl$

NaOH (aq) + HCl (aq) → NaCl(aq) + $H_2O (l)$

The above equation tells us that $1 \text{mole}$ of $NaOH$ reacts with $1 \text{mole}$ of $HCl$ .

So at the equivalence point, the moles of NaOH added = moles of $HCl$ present.

If the volume of the $HCl$ taken = $V_1$ mL and the conc. of $HCl$ = $M_1$ mole/L

The volume of NaOH added up to the color change = $V_2 \text{ and conc of NaOH = M}_2$ mole/L

Moles of $HCl$ taken = $V_1 \ mL \times M_1 \ mol/100 \ mL = V_2M_2 \times 10^{-3}$ moles.

The color change will occur when the moles of NaOH added is equal to the moles of $HCl$ taken.

Thus when $V_1 M_1 \times 10^{-3} = V_2M_2 \times 10^{-3}$

or when $V_1M_1 = V_2M_2$

or $V_2=\frac{V_1M_1}{M_2}$ mL of NaOH added, we observe the color change.

Where $V_1, M_1$ are the volume and molarity of the $HCl$ taken.

$M_2$ is the molarity of NaOH added.

When both the NaOH and $HCl$ are of the same concentrations, i.e. if $M_1=M_2$ , then $V_2=V_1$

Or the 40 mL of $HCl$ will need 40 mL of NaOH for a color change and

30 mL of $HCl$ would need 30 mL of NaOH for the color change (provided the concentration $M_1=M_2$ )

7 0

3 years ago

How many liters in 4.4 grams of CO2 at STP?

d1i1m1o1n [39]

Answer:

2.24 Liters are in 4.4 grams of CO2 at STP

5 0

4 years ago

A sample of water at 100°C is converted to steam after absorbing 820 kJ of heat. How grams of H2O are contained in the sample? A

Varvara68 [4.7K]

Since water is already at 100°C all the energy is used to evaporate it.
Now we can calculate how many mols of water are evaporated with 820kJ.
$N= \frac{820}{41} =20 mol$
We calculated that we got 20 mols of water evaporated. Now, all we have to do is find how many grams is a mol of water. Molar mass of water is 20.16 g/mol.
The final answer is:
$m=20*20.16=403.2g$

7 0

3 years ago

The element carbon exists in several different forms. Pure carbon can be found in the form of diamonds, coal, and the graphite i

UNO [17]

Answer:

B) All carbon atoms have 6 neutrons.

Explanation:

The false statement from the given choices is that all carbon atoms have 6 neutrons.

There is a phenomenon called isotopy in chemistry.

Isotopy is the existence of two or more atoms of the same element having the same atomic number but different mass numbers due to the differences in the number of neutrons in their various nuclei.

These atoms of elements are called isotopes.
Carbon atoms generally have proton number of 6 which is the same as the atomic number.
As with all atoms, the mass number or atomic mass equals the number of protons and neutrons.

For the isotopes of carbon, their number of neutrons differs.

For example:

¹²₆C ¹³₆C ¹⁴₆C

The number of neutrons differs in the above isotopes.

Number of neutrons = mass number - atomic number;

¹²₆C , number of neutrons = 12 - 6 = 6

¹³₆C, number of neutrons = 13 - 6 = 7

¹⁴₆C, number of neutrons = 14 - 6 = 8

Therefore, based on the concept of isotopy, all carbon atoms do not have 6 neutrons.

7 0

3 years ago

How does the flow of energy during freezing compare with the flow of energy during melting

lianna [129]

Answer:

At the melting point, some molecules overcome the forces of attraction. Energy gained after the the solid melts increases the average kinetic energy or the temperature. When liquid is freezing the energy flows out the the liquid. As the kinetic energy decreases, they move more slowly.

Explanation:

3 0

3 years ago