The value of ΔH° for the reaction below is -126 kJ. The amount of heat that is released by the reaction of 25.0 g of Na2O2 with water is kJ. 2Na2O2(s) + 2H2O(l) → 4NaOH(s) + O2(g) The value of ΔH° for the reaction below is -126 kJ. The amount of heat that is released by the reaction of 25.0 g of Na2O2 with water is kJ. 2Na2O2(s) + 2H2O(l) → 4NaOH(s) + O2(g) 40.4 80.8 -126 67.5 20.2

Answers

Answer 1

Answer:

The amount of heat that is released by the chemical reaction of 25.0 g of $Na_(2)O_2$ with water is -20.223 Joules.

Given the following data:

Mass of $Na_(2)O_2$ = 25.0 grams

Enthalpy of combustion = -126 kJ/mol

To find the amount of heat that is released by the chemical reaction of 25.0 g of $Na_(2)O_2$ with water:

First of all, we would determine the number of moles of $Na_(2)O_2$ in this chemical reaction:

$2Na_2O_2_((s)) + 2H_2O_((l))$ ------> $4NaOH_((s)) + O_2_((g))$

$Number\;of\;moles \;(Na_(2)O_2)= (Mass\; of\;Na_(2)O_2)/(Molar\;mass\;of\;Na_(2)O_2)$

Substituting the values into the formula, we have;

$Number\;of\;moles \;(Na_(2)O_2)= (25.0)/(77.98)$

Number of moles ( $Na_(2)O_2$ ) = 0.321 moles.

Now, we can find the quantity of heat released when $Na_(2)O_2$ reacts with water:

2 mole of $Na_(2)O_2$ = -126 kJ/mol

0.321 mole of $Na_(2)O_2$ = X kJ/mol

Cross-multiplying, we have:

$2X = 0.321$ × $(-126)$

$2X = -40.446\n\nX = (-40.446)/(2)$

X = -20.223 Joules.

Answer 2

Answer:

Answer : The amount of heat released by the reaction is, 20.2 kJ

Explanation :

First we have to calculate the number of moles of $Na_2O_2$ .

$\text{Moles of }Na_2O_2=\frac{\text{Mass of }Na_2O_2}{\text{Molar mass of }Na_2O_2}$

Molar mass of $Na_2O_2$ = 77.98 g/mole

$\text{Moles of }Na_2O_2=(25.0g)/(77.98g/mole)=0.320mole$

Now we have to calculate the heat released during the reaction.

The balanced chemical reaction is:

$2Na_2O_2(s)+2H_2O(l)\rightarrow 4NaOH(s)+O_2(g)$

From the reaction we conclude that,

As, 2 moles of $Na_2O_2$ releases heat = 126 kJ

So, 0.320 moles of $Na_2O_2$ releases heat = $(0.320)/(2)* 126=20.2kJ$

Therefore, the amount of heat released by the reaction is, 20.2 kJ

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Answers

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What is the Ka’aba?an Islamic deity
a Muslim pilgrim
a book of Sharia laws
an ancient stone temple

Answers

Answer: Ka'aba is Muslim pilgrimage

Explanation: Kaaba is a small shrine located in Mecca and is considered as a sacred spot by Muslims.

It is a cube shaped structure made up of graystone and marble. It's corners correspond to the points of a compass and is mostly kept covered with a cloth called kiswah.

Answer:

D. An ancient Stone Temple

Explanation:

Edg 2021

If 20.0 ml of glacial acetic acid (pure hc2h3o2 is diluted to 1.70 l with water, what is the ph of the resulting solution? the density of glacial acetic acid is 1.05 g/ml.

Answers

The pH of the resulting solution is 2.72

Data;

volume of acid = 20mL
density of acid = 1.05 g/ml
mass = 1.05 * 20 = 21g

pH of a solution

The number of moles of acetic acid is

$n = 21/60 = 0.333 moles$

The concentration of acetic acid in 1.7L is

$c = (0.333)/(1.7) = 0.196M$

The equation for dissociation is

$CH_3COOH + H_2O \to CH_3COO^- +H_3O^+$

The Ka of this reaction is

$K_a = ([CH_3COO^-][H_3O^+)/([CH_3COOH)$

The Ka of acetic acid = 1.8*10^-5

$1.8*10^-^5 = (x*x)/(0.196) \nx = 0.187*10^-^2M\n$

The concentration of hydrogen ion is

$[H^+] = 1.87*10^-^3M$

The pH of this solution is

$pH = -log[H^+]\npH = -log(1.87*10^-^3)\npH = 2.72$

The pH of the resulting solution is 2.72

Learn more on pH of a solution here;

brainly.com/question/25639733

Given:
20.0 ml of glacial acetic acid
1.70 L with water
density of the glacial acetic acid is 1.05 g/ml ; Ka = 1.8 x 10⁻⁵

1) find out how many grams of HC2H3O2 is in this glacial matter. It says here it has a density of 1.05g/mL.
So we find the grams from that => 1.05 g/mL * (20.0 mL) = 21 grams of HC2H3O2.
Convert this to moles => 21 grams (1 mol / 60 g) = 0.35 mol HC2H3O2

We then get the Ka formula from that equation so it is
Ka = [H3O+] [C2H3O2] / [HC2H3O2] (Remember H2O has an activity of 1 so we exclude it)

We know the concentration of HC2H3O2 because we have moles of HC2H3O2
Finding concentration of HC2H3O2 => 0.35 mol HC2H3O2/1.70 L = 0.20588 M - initial concentration

1.8 x 10⁻⁵ = (x) (x) / (0.20588 M - x)
1.8 X 10⁻⁵ (0.20588 M) = x²
3.70584⁻ x 10⁻⁶ = x²
x = 1.9251 x 10⁻³

pH = -log (H₃O⁺) = - log (1.9251 x 10⁻³) = -(-2.7156) = 2.7156

pH of the resulting solution is 2.7156

if you are finding the value of a 10 g piece of metal that has a value of 5 dollars/ 1 gram what would be my final unit

Answers

5/1 = 10/x

5x = 10
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Why does a reaction involving a catalyst finally stop

Answers

Answer:

Explanation:

Catalysis is a process that accelerates chemical reactions due to molecules called catalysts, which provide ways to reach products that require less energy.

A catalyst intervenes in the reaction mechanism, but is not consumed. This means that the catalyst participates in some stage of the reaction, but then regenerates.

In addition, a catalyst is used in a small amount: a minimum mole percentage, with respect to reagents, is usually required to observe an increase in velocity.

There are three types of catalysis:

Homogeneous: the catalyst is present in the same phase as the species that react.
Heterogeneous: the catalyst and reagents are in a different phase.
Enzyme: occurs only in living beings, and in these cases the catalysts are enzymes.

The absence of a catalyst can make the reaction so slow that it never occurs. Therefore, when the catalyst of a reaction is removed, the reaction may stop.

When the catalyst is a reaction is removed by the reaction, this reaction will stop as there won't be any agent causing it anymore. !

Which molecule contains a triple covalent
bond?
(1) H2 (3) O2
(2) N2 (4) Cl2

Answers

Answer: The correct answer is Option 2.

Explanation:

Covalent bond is defined as the b which is formed by the sharing of electrons between the atoms forming a bond.

Non-polar covalent bond is defined as the bond which is formed when there is no difference in electronegativity between the atoms. When atoms of the same element combine, it results in the formation of non-polar covalent bond. For Example: $N_2,O_2$ etc..

For the given options:

Option 1: $H_2$

Hydrogen is the 1st element of the periodic table having electronic configuration $1s^1$

This element needs 1 electron to attain stable electronic configuration and will form single covalent bond with another hydrogen atom.

Option 2: $N_2$

Nitrogen is the 7th element of the periodic table having electronic configuration $1s^22s^22p^3$

This element needs 3 electrons to attain stable electronic configuration and will form triple covalent bond with another nitrogen atom.

Option 3: $O_2$

Oxygen is the 8th element of the periodic table having electronic configuration $1s^22s^22p^4$

This element needs 2 electrons to attain stable electronic configuration and will form double covalent bond with another oxygen atom.

Option 4: $Cl_2$

Chlorine is the 17th element of the periodic table having electronic configuration $1s^22s^22p^63s^23p^5$

This element needs 1 electron to attain stable electronic configuration and will form single covalent bond with another chlorine atom.

Hence, the correct answer is Option 2.

N2 because it has 5 valence atoms so it needs 3 to have 8, wich is the octet rule, so three is a triple covalent bond

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