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3 years ago

How many grams of Helium can be found in 3.4 moles of it.

Chemistry

1 answer:

MaRussiya [10]3 years ago

5 0

one mole

If we look this number up for helium, we find that helium has a molar mass of 4.0 grams per mole. So one mole of helium has a mass of 4.0 grams. We can use the molar mass as a conversion factor. Two moles of helium times four grams of helium per mole of helium is equal to eight grams of helium.

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Help me out please this is hard

Brums [2.3K]

The one you have selected is correct. CO is a compound because it contains more than one element.

8 0

3 years ago

Read 2 more answers

A compound with chemical formula na2cx3 has formula mass 106 amu .. what is the atomic mass of element x

maria [59]

The element "X" is "O" (oxygen).

<h3>Calculation:</h3>

Given,

Chemical formula = Na₂CX₃

Formula mass = 106 amu

Molar mass of Na = 23 amu

Molar mass of C = 12 amu

To find,

Element X =?

We will equate the equation as follows,

2(23) + 12 + 3(y) = 106

46 + 12 + 3y =106

58 + 3y = 106

3y = 106 - 58

3y = 48

y = 48/3

y = 16

We know that Oxygen has molecular mass of 16. Therefore the element "X" is "O".

Learn more about molar mass here:

brainly.com/question/22997914

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5 0

2 years ago

Write the word equation for the chemical reaction: Zn(s)+2HCl2(aq)--->ZnCl2(aq)+H2(g)

Vikki [24]

Zn(s) + 2HCl(aq) = ZnCl₂(aq) + H₂(g)

zinc + hydrochloric acid = zinc chloride + hydrogen

4 0

3 years ago

What is the concentration (in M) of a sample of the unknown dye with an absorbance of 0.25 at 542 nm?

Sladkaya [172]

Answer:

see explanation below

Explanation:

Question is incomplete, so in picture 1, you have a sample of this question with the missing data.

Now, in general terms, the absorbance of a substance can be calculated using the beer's law which is the following:

A = εlc

Where:

ε: molar absortivity

l: distance of the light in solution

c: concentration of solution

However, in this case, we have a plot line and a equation for this plot, so all we have to do is replace the given data into the equation and solve for x, which is the concentration.

the equation according to the plot is:

A = 15200c - 0.018

So solving for C for an absorbance of 0.25 is:

0.25 = 15200c - 0.018

0.25 + 0.018 = 15200c

0.268 = 15200c

c = 0.268/15200

c = 1.76x10⁻⁵ M

5 0

3 years ago

Will give lots of points if answered correctly. Determine the kb for chloroform when 0.793 moles of solute in 0.758 kg changes t

Liono4ka [1.6K]

Answer: The value of $K_{b}$ for chloroform is $3.62^{o}C/m$ when 0.793 moles of solute in 0.758 kg changes the boiling point by 3.80 °C.

Explanation:

Given: Moles of solute = 0.793 mol

Mass of solvent = 0.758

$\Delta T_{b} = 3.80^{o}C$

As molality is the number of moles of solute present in kg of solvent. Hence, molality of given solution is calculated as follows.

$Molality = \frac{no. of moles}{mass of solvent (in kg)}\\= \frac{0.793 mol}{0.758 kg}\\= 1.05 m$

Now, the values of $K_b$ is calculated as follows.

$\Delta T_{b} = i\times K_{b} \times m$

where,

i = Van't Hoff factor = 1 (for chloroform)

m = molality

$K_{b}$ = molal boiling point elevation constant

Substitute the values into above formula as follows.

$\Delta T_{b} = i\times K_{b} \times m\\3.80^{o}C = 1 \times K_{b} \times 1.05 m\\K_{b} = 3.62^{o}C/m$

Thus, we can conclude that the value of $K_{b}$ for chloroform is $3.62^{o}C/m$ when 0.793 moles of solute in 0.758 kg changes the boiling point by 3.80 °C.

7 0

3 years ago