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3 years ago

If you have 5.42 x 1024 aluminum atoms, approximately how many moles is that

Chemistry

1 answer:

sattari [20]3 years ago

4 0

Answer:

<h2>9.00 moles</h2>

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

$n = \frac{5.42 \times {10}^{24} }{6.02 \times {10}^{23} } \\ = 9.0033$

We have the final answer as

<h3>9.00 moles</h3>

Hope this helps you

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Part A Find ΔS∘ for the reaction between nitrogen gas and hydrogen gas to form ammonia: 12N2(g)+32H2(g)→NH3(g) Express your answ

inessss [21]

Answer:

$\Delta S^{0}$ for the given reaction is -99.4 J/K

Explanation:

Balanced reaction: $\frac{1}{2}N_{2}(g)+\frac{3}{2}H_{2}(g)\rightarrow NH_{3}(g)$

$\Delta S^{0}=[1mol\times S^{0}(NH_{3})_{g}]-[\frac{1}{2}mol\times S^{0}(N_{2})_{g}]-[\frac{3}{2}mol\times S^{0}(H_{2})_{g}]$

where $S^{0}$ represents standard entropy.

Plug in all the standard entropy values from available literature in the above equation:

$\Delta S^{0}=[1mol\times 192.45\frac{J}{mol.K}]-[\frac{1}{2}mol\times 191.61\frac{J}{mol.K}]-[\frac{3}{2}mol\times 130.684\frac{J}{mol.K}]=-99.4J/K$

So, $\Delta S^{0}$ for the given reaction is -99.4 J/K

7 0

3 years ago

A volume of 90.0 mLmL of aqueous potassium hydroxide (KOHKOH) was titrated against a standard solution of sulfuric acid (H2SO4H2

Alja [10]

Answer:

0.823 M was the molarity of the KOH solution.

Explanation:

$H_2SO_4+KOH\rightarrow K_2SO_4+2H_2O$ (Neutralization reaction)

To calculate the concentration of base , we use the equation given by neutralization reaction:

$n_1M_1V_1=n_2M_2V_2$

where,

$n_1,M_1\text{ and }V_1$ are the n-factor, molarity and volume of acid which is $H_2SO_4$

$n_2,M_2\text{ and }V_2$ are the n-factor, molarity and volume of base which is KOH.

We are given:

$n_1=2\\M_1=1.50 M\\V_1=24.7 mL\\n_2=1\\M_2=?\\V_2=90.0 mL$

Putting values in above equation, we get:

$2\times \1.50 M\times 24.7 mL=1\times M_2\times 90.0 mL$

$M_2=\frac{2\times 1.50M\times 24.7 mL}{1\times 90.0 mL}=0.823 M$

0.823 M was the molarity of the KOH solution.

7 0

3 years ago

What is a product for 4 reaction type?

Crank

Answer:

1= 2H₂ + O₂ → 2H₂O

2=CaCo₃ + heat → CaO +CO₂

3=CH₄ + 2O₂ → CO₂ +2H₂O

4=HCl + NaOH → NaCl + H₂O

Explanation:

1 = Simple composition

The formation of water molecule is simple composition reaction. In this reaction two hydrogen atoms react with one oxygen atom and form one water molecules.

2H₂ + O₂ → 2H₂O

The amount of energy released is -285.83 KJ/mol. It is exothermic reaction.

2 = Simple decomposition reaction:

The break down of sodium hydrogen carbonate into sodium carbonate, carbondioxide and water is decomposition reaction. The decomposition reactions re mostly endothermic, because compound required energy to break.

2NaHCO₃ + heat → Na₂CO₃ + H₂O + CO₂

It is endothermic reaction.

Another example is:

CaCo₃ + heat → CaO +CO₂

3 = Combustion reaction

Consider the combustion of methane:

CH₄ + 2O₂ → CO₂ +2H₂O

The burning of methane is exothermic. The combustion reactions are exothermic because when fuel are burns they gives energy.

4 = Neutralization reaction

The neutralization reactions are those in which acid and base react to form the salt and the water. Some neutralization reactions are exothermic because they release heat. e.g

Consider the neutralization reaction of HCl and NaOH.

HCl + NaOH → NaCl + H₂O

6 0

3 years ago

Why don't protins stick together

irinina [24]

Because proteins are basically building blocks which mean that they only fit to specific pieces.

3 0

2 years ago

A student is learning about a particular chemical element. The element is a metal that readily forms ionic salts with nonmetals

seropon [69]

Answer:

Group 2

Explanation:

Because group 2 is very reactive and forms salts with other non metals. Example Calcium Chloride. Calcium is from group 2, forms ionic salts with other non metal, and exists as solid at standard temp and pressure.

3 0

3 years ago

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