All categories

2 years ago

How many moles are in 1.42 x 10^25 molecules of NaCl?

Chemistry

1 answer:

Sholpan [36]2 years ago

3 0

<h3>Answer:</h3>

23.6 mol NaCl

<h3>General Formulas and Concepts:</h3>

<u>Pre-Algebra</u>

Order of Operations: BPEMDAS

Brackets
Parenthesis
Exponents
Multiplication
Division
Addition
Subtraction

Left to Right<u> </u>

<u>Chemistry</u>

<u>Atomic Structure</u>

Avogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.

<u>Stoichiometry</u>

Reading a Periodic Table

<h3>Explanation:</h3>

<u>Step 1: Define</u>

1.42 × 10²⁵ molecules NaCl

<u>Step 2: Identify Conversions</u>

Avogadro's Number

<u>Step 3: Convert</u>

Set up: $\displaystyle 1.42 \cdot 10^{25} \ molecules \ NaCl(\frac{1 \ mol \ NaCl}{6.022 \cdot 10^{23} \ molecules \ NaCl})$
Multiply/Divide: $\displaystyle 23.5802 \ mol \ NaCl$

<u>Step 4: Check</u>

<em>Follow sig fig rules and round. We are given 3 sig figs.</em>

23.5802 mol NaCl ≈ 23.6 mol NaCl

You might be interested in

A student claims that if she wanted to make a solution quickly, she should use small pellets instead of powder along with heatin

vova2212 [387]

Answer: Yes we agree with the student's claim.

Explanation:

When the molecules are present in smaller size, more reactants can react as decreasing the size increases the surface area of the reactants which will enhance the contact of molecules.Hence, more products will form leading to increased rate of reaction.

On increasing the temperature will make more reactant molecules will have sufficient energies to cross the energy barrier and thus the number of effective collisions increases, thus leading to more products and increased rate of reaction.

When the solution is stirred , the molecule's kinetic energy and thus the rate of reaction increases.

Thus smaller size, stirring and increase of temperature will make the solution quickly.

7 0

3 years ago

Enthalpies of reaction calculated from bond energies and from enthalpies of formation are often, but not always, close to each o

jolli1 [7]

The enthalpy change in a reaction is given by-

ΔH°rxn = ∑nΔH°f,products - ∑nΔH°f,reactants

This can be expressed in terms of bond energy as-

ΔH°rxn = BEreactants - BEproducts

Therefore, the calculated bond energy according to the above equation will be-

ΔH°rxn = [ (C-C) + 2(C-O) + 4(C-H) + 2(O-H) ] - [ (C-C) + 2(C-O) + 4(C-H) + 2(O-H) = 0 kJ/mol

<h3>What is enthalpy change?</h3>

Enthalpy change is a measure of the energy emitted or consumed in a reaction. This can be determined using the following equation which involves standard enthalpy of reactant and product formation:

ΔH°rxn = ∑nΔH°f,products - ∑nΔH°f,reactants

<h3>What is bond energy?</h3>

Bond energy is defined as the amount of energy needed to dissociate a mole of molecules into their individual atoms.

Learn more about the Enthalpy Change here:

brainly.com/question/14047927

#SPJ4

6 0

2 years ago

Be sure to answer all parts. Nitric oxide, NO·, is a radical thought to cause ozone destruction by a mechanism similar to that o

SIZIF [17.4K]

Answer:

See image attached and explanation

Explanation:

The stratospheric ozone layer is very important in absorbing high-energy ultraviolet radiation that is harmful to living systems on earth. The concentration of ozone in the stratosphere is determined by both thermal and photochemical pathways for its decomposition. Nitric oxide, NO, is a trace constituent in the stratosphere that reacts with ozone to form nitrogen dioxide, NO2, and the diatomic oxygen molecule. The nitrogen-oxygen bond in NO2 is relatively weak. When an NO2 molecule encounters an oxygen atom, it transfers an oxygen, forming O2 and NO. The chemical reactions involved are formations of NO2 following by reaction of NO2 with atomic oxygen for form NO and O2. The sum of both reactions show that the overall reaction is simply the reaction of ozone with atomic oxygen to form two molecules of molecular oxygen. Hence, NO only serves as a catalyst, it does not undergo a permanent change itself.