All categories

3 years ago

What is the correct answer?!????

Chemistry

1 answer:

ddd [48]3 years ago

4 0

Answer:

Explanation:

Dalton worked with mainly about the chemistry of atoms.

how do atoms combine to form various molecules.

—rather than the details of the physical, internal structure of atoms, although he never denied the possibility of atoms' having a substructure.

You might be interested in

PLEASE HELP THANKS:))))))

weeeeeb [17]

Explanation:

-plants that can absorb copper ions are grown on soil with low grade copper ores.

-the plants are burned and the copper compounds are within the Ash.

-copper ions can be leached from the Ash by adding sulphuric acid, this makes a solution of copper sulphate

-the displacement of scrap iron makes pure copper metals.

3 0

3 years ago

Calculate the wavelength of a football (425g) thrown by an NFL quarterback traveling at 50mph

AnnyKZ [126]

Wavelength is 6.976 x 10^ -35 m

Explanation:

In this, we can use De Broglie’s equation. This equation is the relationship between De Broglie’s wavelength, velocity and the mass of a moving object. In this equation, we are using plank's constant which is 6.626 x 10^-34 m^2 kg/s.

We know that one mile per hour is equivalent to 0.447 M/S.

And One gram is equivalent to 10^-3 kg.

De Broglie’s wavelength = λ ( wave length) = Plank’s constant/ Mass x velocity

λ ( wave length) = 6.626 x 10^ -34/ (425 x10^-3) x ( 50 x 0.447)

= 6.626 x 10^ -34/ 0. 425 x 22.35

= 6.626 x 10^ -34/ 9.498

= 6.976 x10^ -35 m

So, the wavelength of the football will be 6.976 x 10^ -35 m

7 0

3 years ago

What must be the molarity of an aqueous solution of trimethylamine, (ch3)3n, if it has a ph = 11.20? (ch3)3n+h2o⇌(ch3)3nh++oh−kb

Stolb23 [73]

0.040 mol / dm³. (2 sig. fig.)

<h3>Explanation</h3>

$(\text{CH}_3)_3\text{N}$ in this question acts as a weak base. As seen in the equation in the question, $(\text{CH}_3)_3\text{N}$ produces $\text{OH}^{-}$ rather than $\text{H}^{+}$ when it dissolves in water. The concentration of $\text{OH}^{-}$ will likely be more useful than that of $\text{H}^{+}$ for the calculations here.

Finding the value of $[\text{OH}^{-}]$ from pH:

Assume that $\text{pK}_w = 14$ ,

$\begin{array}{ll}\text{pOH} = \text{pK}_w - \text{pH} \\ \phantom{\text{pOH}} = 14 - 11.20 &\text{True only under room temperature where }\text{pK}_w = 14 \\\phantom{\text{pOH}}= 2.80\end{array}$ .

$[\text{OH}^{-}] =10^{-\text{pOH}} =10^{-2.80} = 1.59\;\text{mol}\cdot\text{dm}^{-3}$ .

Solve for $[(\text{CH}_3)_3\text{N}]_\text{initial}$ :

$\dfrac{[\text{OH}^{-}]_\text{equilibrium}\cdot[(\text{CH}_3)_3\text{NH}^{+}]_\text{equilibrium}}{[(\text{CH}_3)_3\text{N}]_\text{equilibrium}} = \text{K}_b = 1.58\times 10^{-3}$

Note that water isn't part of this expression.

The value of Kb is quite small. The change in $(\text{CH}_3)_3\text{N}$ is nearly negligible once it dissolves. In other words,

$[(\text{CH}_3)_3\text{N}]_\text{initial} = [(\text{CH}_3)_3\text{N}]_\text{final}$ .

Also, for each mole of $\text{OH}^{-}$ produced, one mole of $(\text{CH}_3)_3\text{NH}^{+}$ was also produced. The solution started with a small amount of either species. As a result,

$[(\text{CH}_3)_3\text{NH}^{+}] = [\text{OH}^{-}] = 10^{-2.80} = 1.58\times 10^{-3}\;\text{mol}\cdot\text{dm}^{-3}$ .

$\dfrac{[\text{OH}^{-}]_\text{equilibrium}\cdot[(\text{CH}_3)_3\text{NH}^{+}]_\text{equilibrium}}{[(\text{CH}_3)_3\text{N}]_\textbf{initial}} = \text{K}_b = 1.58\times 10^{-3}$ ,

$[(\text{CH}_3)_3\text{N}]_\textbf{initial} =\dfrac{[\text{OH}^{-}]_\text{equilibrium}\cdot[(\text{CH}_3)_3\text{NH}^{+}]_\text{equilibrium}}{\text{K}_b}$ ,

$[(\text{CH}_3)_3\text{N}]_\text{initial} =\dfrac{(1.58\times10^{-3})^{2}}{6.3\times10^{-5}} = 0.040\;\text{mol}\cdot\text{dm}^{-3}$ .

8 0

3 years ago

Which geoigic feature is most likey to from a mid

zvonat [6]

should be ocean ridges im not sure hope this helps tho

6 0

2 years ago

Read 2 more answers

A. List the potential acute health effects.

AleksandrR [38]

When we handle chemical substances we must be very careful because they can put our:

Physical integrity.
Health
Life at risk.

<h3>What is a chemical?</h3>

A chemical substance is a chemical compound resulting from the union of two or more chemical elements. Compounds have different uses depending on their properties. However, some can be harmful and life-threatening to humans.

<h3>Potential acute effects.</h3>

The potential acute effects of some compounds may be related to skin contact causing:

Inflammation
Redness
Rash
Burns
Dry
Among other.

On the other hand, the chronic effects of chemical compounds can be:

Diseases in the central nervous system.
Respiratory diseases.
Skin diseases.
Degenerative diseases of the bone system.

<h3>What to do when a chemical is ingested?</h3>

There are a large number of chemical substances and each one has different properties. Therefore, it is very difficult to generalize about a treatment in case of ingestion. What must be done is to know the level of risk of the substance that is being handled and avoid ingesting it at all costs. However, if it is ingested, go to the emergency room.

<h3>Product flammability</h3>

Not all chemical compounds have the same flammable response to fire. Due to the above, it is necessary to identify if the substance that we are handling is highly or slightly flammable, for this we can consult the manual of the substance or the label of its packaging.

<h3>3 Chemical that produces a potentially dangerous reaction with hydrochloric acid.</h3>

According to some studies and the hydrochloric acid safety data sheet, it can have dangerous reactions with:

Reacts violently with water.
Gives off hydrogen in reaction with metals.
Keep away from strong bases.

<h3>How to handle small spills?</h3>

Contain the spill.
Soak up with inert absorbent material.
Prevent the product from entering the sewage system.
Keep in suitable, closed containers for disposal.

<h3>Personal Protection</h3>

When we handle chemical substances we are facing a potential risk. Due to the above, protocols have been developed for its handling, which include the use of protection elements such as:

Gloves
Glasses
Helmet
Mask
Boots
Special suit.
Among others.

Learn more about chemical compounds in: brainly.com/question/14498747

5 0

2 years ago