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3 years ago

3. How many moles are in 1.49 x 1023 molecules of iodine?

Chemistry

1 answer:

tino4ka555 [31]3 years ago

7 0

Answer:

<h3>The answer is 0.25 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

$n = \frac{1.49 \times {10}^{23} }{6.02 \times {10}^{23} } = \frac{1.49}{6.02} \\ = 0.247508305...$

We have the final answer as

<h3>0.25 moles</h3>

Hope this helps you

You might be interested in

Determine the molecular formula for each of the following compounds from the

bulgar [2K]

The molecular formula for each of the following compound given the data is

C₂H₆
C₂H₂
C₄H₈Cl₂

<h3>A. How to determine the molecular formula </h3>

We'll begin by calculating the empirical formula. This can be obtained as follow:

C = 80%
H = 20%
Empirical formula =?

Divide by their molar mass

C = 80 / 12 = 6.67

H = 20 / 1 = 20

Divide by the smallest

C = 6.67 / 6.67 = 1

H = 20 / 6.67 = 3

Thus, the empirical formula of the compound CH₃

Thus, the molecular formula of the compound can be obtained as follow

Empirical formula = CH₃
Molar mass of compound = 30 g/mol
Molecular formula =?

Molecular formula = empirical × n = mass number

[CH₃]n = 30

[12 + (3×1)]n = 30

15n = 30

Divide both side by 15

n = 30 / 15

n = 2

Molecular formula = [CH₃]n

Molecular formula = [CH₃]₂

Molecular formula = C₂H₆

Thus, the molecular formula of the compound is C₂H₆

<h3>B. How to determine the molecular formula </h3>

We'll begin by calculating the empirical formula. This can be obtained as follow:

C = 92.3%
H = 7.7%
Empirical formula =?

Divide by their molar mass

C = 92.3 / 12 = 7.7

H = 7.7 / 1 = 7.7

Divide by the smallest

C = 7.7 / 7.7 = 1

H = 7.7 / 7.7 = 1

Thus, the empirical formula of the compound CH

Thus, the molecular formula of the compound can be obtained as follow

Empirical formula = CH
Molar mass of compound = 26 g/mol
Molecular formula =?

Molecular formula = empirical × n = mass number

[CH]n = 26

[12 + 1]n = 26

13n = 26

Divide both side by 13

n = 26 / 13

n = 2

Molecular formula = [CH]n

Molecular formula = [CH]₂

Molecular formula = C₂H₂

Thus, the molecular formula of the compound is C₂H₂

<h3>C. How to determine the molecular formula </h3>

We'll begin by calculating the empirical formula. This can be obtained as follow:

C = 37.5%
H = 6.3%
Cl = 55.8%
Empirical formula =?

Divide by their molar mass

C = 37.5 / 12 = 3.125

H = 6.3 / 1 = 6.3

Cl = 55.8 / 35.5 = 1.572

Divide by the smallest

C = 3.125 / 1.572 = 2

H = 6.3 / 1.572 = 4

Cl = 1.572 / 1.572 = 1

Thus, the empirical formula of the compound C₂H₄Cl

Thus, the molecular formula of the compound can be obtained as follow

Empirical formula = C₂H₄Cl
Molar mass of compound = 127 g/mol
Molecular formula =?

Molecular formula = empirical × n = mass number

[C₂H₄Cl]n = 127

[(2×12) + (4×1) + 35.5]n = 127

63.5n = 127

Divide both side by 63.5

n = 127 / 63.5

n = 2

Molecular formula = [C₂H₄Cl]n

Molecular formula = [C₂H₄Cl]₂

Molecular formula = C₄H₈Cl₂

Thus, the molecular formula of the compound is C₄H₈Cl₂

Learn more about empirical formula:

brainly.com/question/24297883

#SPJ1

7 0

2 years ago

Which element has the least density at STP?

vladimir2022 [97]

Answer:

Helium, this noble gas has the least density at STP

Explanation:

8 0

3 years ago

The flask contains 10.0 mL of HCl and a few drops of phenolphthalein indicator. The buret contains 0.160 M NaOH. It requires 18.

olchik [2.2K]

Answer:

Approximately $0.291\; \rm M$ (rounded to two significant figures.)

Explanation:

The unit of concentration $\rm M$ is the same as $\rm mol \cdot L^{-1}$ (moles per liter.) On the other hand, the volume of both the $\rm NaOH$ solution and the original $\rm HCl$ solution here are in milliliters. Convert these two volumes to liters:

$V(\mathrm{NaOH}) = 18.2\; \rm mL = 18.2 \times 10^{-3}\; \rm L = 0.0182\; \rm L$ .
$V(\text{$\mathrm{HCl}$, original}) = 10.0\; \rm mL = 10.0\times 10^{-3}\; \rm L = 0.0100\; \rm L$ .

Calculate the number of moles of $\rm NaOH$ in that $0.0182\; \rm L$ of $0.160\; \rm M$ solution:

$\begin{aligned} n(\mathrm{NaOH}) &= c(\mathrm{NaOH})\cdot V(\mathrm{NaOH})\\ &= 0.160\; \rm mol \cdot L^{-1} \times 0.0182\; \rm L \approx 0.00291\; \rm mol\end{aligned}$ .

$\rm HCl$ reacts with $\rm NaOH$ at a one-to-one ratio:

$\rm HCl\; (aq) + NaOH\; (aq) \to NaCl\; (aq) + H_2O\; (l)$ .

Coefficient ratio:

$\displaystyle \frac{n(\mathrm{HCl})}{n(\mathrm{NaOH})} = 1$ .

In other words, one mole of $\rm NaOH$ would neutralize exactly one mole of $\rm HCl$ . In this titration, $0.291\; \rm mol$ of $\rm NaOH\!$ was required. Therefore, the same amount of $\rm HC$ should be present in the original solution:

$\begin{aligned}&n(\text{$\mathrm{HCl}$, original})\\ &= n(\mathrm{NaOH})\cdot \frac{n(\mathrm{HCl})}{n(\mathrm{NaOH})} \\ &\approx 0.00291\; \rm mol \times 1 = 0.00291\; \rm mol\end{aligned}$ .

Calculate the concentration of the original $\rm HCl$ solution:

$\displaystyle c(\text{$\mathrm{HCl}$, original}) = \frac{n(\text{$\mathrm{HCl}$, original})}{V(\text{$\mathrm{HCl}$, original})} \approx \frac{0.00291\; \rm mol}{0.0100\; \rm L} \approx 0.291\; \rm M$ .

5 0

3 years ago

A solution containing CaCl2 is mixed with a solution of Li2C2O4 to form a solution that is 3.5 × 10-4 M in calcium ion and 2.33

Burka [1]

Answer:

B. A precipitate will form since Q > Ksp for calcium oxalate

Explanation:

Ksp of CaC₂O₄ is:

CaC₂O₄(s) ⇄ Ca²⁺ + C₂O₄²⁻

Where Ksp is defined as the product of concentrations of Ca²⁺ and C₂O₄²⁻ in equilibrium:

Ksp = [Ca²⁺][C₂O₄²⁻] = 2.27x10⁻⁹

In the solution, the concentration of calcium ion is 3.5x10⁻⁴M and concentration of oxalate ion is 2.33x10⁻⁴M.

Replacing in Ksp formula:

[3.5x10⁻⁴M][2.33x10⁻⁴M] = 8.155x10⁻⁸. This value is reaction quotient, Q.

If Q is higher than Ksp, the ions will produce the precipitate CaC₂O₄ until [Ca²⁺][C₂O₄²⁻] = Ksp.

Thus, right answer is:

<em>B. A precipitate will form since Q > Ksp for calcium oxalate</em>

4 0

3 years ago

According to the phase diagram for water, how is the state of water determined?

ad-work [718]

I believe it’s 2? Because it’s saying read the temperature. Which is basically saying look at what state the water is in. Ex: hot or cold

5 0

3 years ago

Read 2 more answers