Arrange the following objects in order from smallest to largest:

Convert 4.5 X 1022 molecules of H2O to moles.

noname [10]

Answer:

<h3>The answer is 0.075 moles</h3>

Explanation:

To find the number of moles in a substance given it's number of entities we use the formula

$n = \frac{N}{L} \\$

where n is the number of moles

N is the number of entities

L is the Avogadro's constant which is

6.02 × 10²³ entities

From the question we have

$n = \frac{4.5 \times {10}^{22} }{6.02 \times {10}^{23} } \\ = 0.074750830...$

We have the final answer as

<h3>0.075 moles</h3>

Hope this helps you

3 0

3 years ago

A hypothetical element has an atomic weight of 48.68 amu. It consists of three isotopes having masses of 47.00 amu, 48.00 amu, a

Morgarella [4.7K]

Answer : The percent abundance of the heaviest isotope is, 78 %

Explanation :

Average atomic mass of an element is defined as the sum of masses of each isotope each multiplied by their natural fractional abundance.

Formula used to calculate average atomic mass follows:

$\text{Average atomic mass }=\sum_{i=1}^n\text{(Atomic mass of an isotopes)}_i\times \text{(Fractional abundance})_i$

As we are given that,

Average atomic mass = 48.68 amu

Mass of heaviest-weight isotope = 49.00 amu

Let the percentage abundance of heaviest-weight isotope = x %

Fractional abundance of heaviest-weight isotope = $\frac{x}{100}$

Mass of lightest-weight isotope = 47.00 amu

Percentage abundance of lightest-weight isotope = 10 %

Fractional abundance of lightest-weight isotope = $\frac{10}{100}$

Mass of middle-weight isotope = 48.00 amu

Percentage abundance of middle-weight isotope = [100 - (x + 10)] % = (90 - x) %

Fractional abundance of middle-weight isotope = $\frac{(90-x)}{100}$

Now put all the given values in above formula, we get:

$48.68=[(47.0\times \frac{10}{100})+(48.0\times \frac{(90-x)}{100})+(49.0\times \frac{x}{100})]$

$x=78\%$

Therefore, the percent abundance of the heaviest isotope is, 78 %

5 0

3 years ago

Read 2 more answers

An element has an atomic mass of 69.66 amu. It has two

marin [14]

Answer: 63.26%

Explanation:

If we let the abundance of the first isotope be x, then:

$69.66=(68.9255)(x)+(70.9247)(1-x)\\69.66=68.9255x+70.9247-70.9247x\\-1.2647=-1.9992x\\x=\frac{-1.2647}{-1.9992} \approx 0.6326$

Which is equal to <u>63.26%</u>

7 0

2 years ago

If the molecule C6H12 does not contain a double bond, and there are no branches in it, what will its structure look like?

NARA [144]

I have attached a photo of the structure.
You can get better at solving problems like this by practicing a lot!

5 0

4 years ago

What is the mole ratio between oxygen and carbon dioxide?<br><br> C25H52 + 38 O2 → 25 CO2 + 26 H2O

user100 [1]

Answer:

38 : 25

Explanation:

First thing's first, we have to confirm if the reaction is indeed balanced.

The equation of the reaction is given as;

C25H52 + 38 O2 → 25 CO2 + 26 H2O

From the reaction, 38 moles of O2 produces 25 moles of CO2

The ratio is given as;

38 : 25

4 0

3 years ago