All categories

3 years ago

How many moles are represented by 3.01x10^23 helium atoms

Chemistry

1 answer:

Alex787 [66]3 years ago

4 0

Answer:

b. 0.50 moles

Explanation:

To solve this problem we use <em>Avogadro's number</em> (6.023x10²³ atoms/mol).

By <u>dividing the number of atoms (or molecules) by that number</u>, we can calculate how many moles they represent.

3.01x10²³ atoms ÷ 6.023x10²³ atoms/mol = 0.50 moles

So the answer is option b. 0.50 moles.

You might be interested in

What has been the effect of increased population on Earth's natural resources?

olya-2409 [2.1K]

Answer:

Generally speaking, as the human population grows, our consumption of natural resources increases. More humans consume more freshwater, more land, more clothing, etc. Scientific and technological innovations mean that we are improving our efficiency at using and harvesting natural resources.

___________________________________

<h3>Please mark me as Brainlist</h3>

5 0

3 years ago

Methane is the main component of natural gas. Using the given reaction enthalpy, calculate the heat energy produced by the combu

SVETLANKA909090 [29]

Answer: The heat energy produced is 53831.25KJ

Explanation:

METHANE is the main component of natural gas. It can undergo combustion reaction in air with a bright blue flame to produce carbondioxide and water. The heat of reaction (enthalpy) is negative because heat is absorbed during the chemical reaction. To calculate the heat energy produced by the combustion of one kilogram (1 kg) of methane the following steps are taken:

Molecular mass of methane =16 gm/mol.

So moles of 1 kg methane =

Given mass of methane ÷ molecular weight of methane

But the given mass = 1kg = 1000g

Therefore,

moles of 1000g methane = 1000÷16

= 62.5 moles

Hence, energy evolved = (moles of methane) × (heat of combustion)

Therefore,

heat energy produced= 62.5 × (-861.3kj)

= -53831.25kj

7 0

3 years ago

What is the volume of 43.7 g of helium at stp?

tankabanditka [31]

Answer is: volume of helium is 244.72 liters.
m(He) = 43.7 g.
n(He) = m(He) ÷ M(He).
n(He) = 43.7 g ÷ 4 g/mol.
n(He) = 10.925 mol.
V(He) = n(He) · n(He).
V(He) = 10.925 mol · 22.4 L/mol.
V(He) = 244.72 L.
Vm - molar volume at STP.
n - amount of substance.

0 0

3 years ago

Read 2 more answers

11. if the ph of a solution increases from 2.0 to 4.0, the h3o^ ion concentration o a decreases by a factor of 2. b. decreases b

Wittaler [7]

Option (B) is the right answer.

Hydronium ion ( $H_{3}O^{+}$ ) concentration decreases by the <u>factor of 100</u>, if the pH of a solution increases from 2.0 to 4.0.

The hydrogen ion concentration in water is expressed by pH. Specific to aqueous solutions, pH is the <u>negative logarithm</u> of the hydrogen ion (H+) concentration (mol/L) : $pH = -log_{10}[H_{3}O^{+} ]$

Acidic solutions are those with a pH under 7, and basic solutions are those with a pH over 7. At this temperature, solutions with a pH of 7 are neutral (e.g.<u> pure water</u>). The pH neutrality <u>relies on temperature, falling below 7 if the temperature rises above 25 °C</u>.

<h3>Given: </h3>

pH1( initial pH) = 2.0

pH2( initial pH) = 4.0

[H3O+] = initial hydronium concentration

[H3O+]* = final hydronium concentration

<h3>Formula used : </h3>

$pH = -log_{10}[H_{3}O^{+}]$

<h3>Solution: </h3>

$pH = - log_{10}[H_{3}O^{+}] \\\\= > 10^{-pH} = [H_{3}O^{+}] \\\\similarly, \\\\10^{-pH} = [H_{3}O^{+}]*\\\\ = > 10^{-4} = [H_{3}O^{+}]*\\\\Now, \frac{[H_{3}O^{+}]*}{[H_{3}O^{+}]} = 10^{-2}$

Thus , the concentration of hydronium ion decreases by 100.

To learn more about pH :

brainly.com/question/15289741

#SPJ4

8 0

2 years ago

Hydrogen has one proton in it's nucleus but exists as three isotopes.

murzikaleks [220]

The Isotope Notation occur by adding the Superscript showing Mass Number and Subscript showing Atomic Number to the Left of the Element Symbol.

Example,

ᵇₐX

Where;
b = Mass Number
a = Atomic Number
X = Symbol
For Hydrogen Isotopes:

1) Protium: 1 Proton , 0 Neutron

¹₁H

2) Deuterium: 1 Proton , 1 Neutron

²₁H

3) Tritium: 1 Proton , 2 Neutron

³₁H

8 0

4 years ago