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3 years ago

How many atoms are in 3.690 moles of oxygen

Chemistry

1 answer:

sweet [91]3 years ago

4 0

1 mole of any substance contains Avogadro's number.

So, 1 mole of O2= 6.023x10^23 molecules

3 mole of O2= 6.023x10^23x3 molecules

= 1.8069x10^24 molecules

Each molecule of Oxygen has 2 atoms.

therefore,

1.8069x10^24 molecules= 1.8069x10^24 x 2 atoms

= 3.6138x10^24 atoms.

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Calculate the oxidation number of the iodine (I) in each compound: HIO4 = I2 = NaI = HIO3 =

Makovka662 [10]

1) in periodic acid (HIO₄), iodine has oxidation number +7, hydrogen has oxidation number +1, oxygen has -2, compound has neutral charge:
+1 + x + 4 · (-2) = 0.
x = +7.

2) in molecule of iodine (I₂), iodine has oxidation number 0, because iodine is nonpolar molecule.

3) in sodium iodide (NaI), iodine has oxidation number -1, sodium has oxidation number +1:
+1 + x = 0.
x = -1.

4) in iodic acid (HIO₃), iodine has oxidation number +5, hydrogen has oxidation number +1, oxygen has -2, compound has neutral charge:
+1 + x + 3 · (-2) = 0.
x = +5.

8 0

3 years ago

Read 2 more answers

What are the molarity and the normality of a solution made

Nikitich [7]

Explanation:

It is known that molarity is the number of moles present in a liter of solution.

Mathematically, Molarity = $\frac{\text{no. of moles}}{\text{volume in liter}}$

Hence, calculate the molarity of given solution as follows.

Molarity of citric acid = $\frac{\text{mass of citric acid}}{\text{molar mass of citric acid}} \times \frac{1}{\text{volume of solution(L)}}$

= $\frac{25 g}{192.13 g/mol} \times \frac{1}{0.75 L}$

= 0.173 M

As citric acid is a triprotic acid so, upon dissociation it gives three hydrogen ions.

Normality = Molarity × no. of hydrogen or hydroxide ions

= 0.173 × 3

= 0.519 N

Thus, we can conclude that molarity of given solution is 0.173 and its normality is 0.519 N.

3 0

3 years ago

What is the charge on an ion that contains 16 protons and 18 electrons?

Alika [10]

16-18= -2 so it has a negative charge. Just subtract the electrons from the protons if you get a positive number it will have a positive charge and vice versa.

6 0

3 years ago

Question 3) A 1.00 L buffer solution is 0.250 M in HF and 0.250 M in LiF. Calculate the pH of the solution after the addition of

Masja [62]

The pH of the solution after adding 0.150 moles of solid LiF is 3.84

<u>Explanation:</u>

We have the chemical equation,

HF (aq)+NaOH(aq)->NaF(aq)+H2O

To find how many moles have been used in this

c= n/V=> n= c.V

nHF=0.250 M⋅1.5 L=0.375 moles HF

Simillarly

nF=0.250 M⋅1.5 L=0.375 moles F

nHF=0.375 moles - 0.250 moles=0.125 moles

nF=0.375 moles+0.250 moles=0.625 moles

[HF]=0.125 moles/1.5 L=0.0834 M

[F−]=0.625 moles/1.5 L=0.4167 M

To determine the problem using the Henderson - Hasselbalch equation

pH=pKa+log ([conjugate base/[weak acid])

Find the value of Ka

pKa=−log(Ka)

pH=−log(Ka) +log([F−]/[HF]

pH= -log(3.5 x 10 ^4)+log(0.4167 M/0.0834 M)

pH=-log(3.5 x 10 ^4)+log(4.996)

pH= -4.54+0.698

pH=-(-3.84)

pH=3.84

The pH of the solution after adding 0.150 moles of solid LiF is 3.84

5 0

3 years ago

If we start with 8000 atoms of radium-226 how much would remain after 3200 years?

olya-2409 [2.1K]

<h3>Answer:</h3>

2000 atoms

<h3>Explanation:</h3>

We are given the following;

Initial number of atoms of radium-226 as 8000 atoms

Time taken for the decay 3200 years

We are required to determine the number of atoms that will remain after 3200 years.

We need to know the half life of Radium

Half life is the time taken by a radio active material to decay by half of its initial amount.

Half life of Radium-226 is 1600 years

Therefore, using the formula;

Remaining amount = Original amount × 0.5^n

where n is the number of half lives

n = 3200 years ÷ 1600 years

= 2

Therefore;

Remaining amount = 8000 atoms × 0.5^2

= 8000 × 0.25

= 2000 atoms

Thus, the number of radium-226 that will remain after 3200 years is 2000 atoms.

6 0

3 years ago