Answer: 10
Explanation:
4Al + 2O2 --> 2Al2O3
This is the balanced equation so there are 2*2 +2*3 = 4+6 =10
Using the equations
2 C₆H₆ (l) + 15 O₂ (g) → 12 CO₂ (g) + 6 H₂O (g)∆H° = -6271 kJ/mol
2 H₂ (g) + O₂ (g) → 2 H₂O (g) ∆H° = -483.6 kJ/mol
C (s) + O₂ (g) → CO₂ (g) ∆H° = -393.5 kJ/mol
Determine the enthalpy (in kJ/mol) for the reaction
6 C (s) + 3 H₂ (g) → C₆H₆ (l).
The enthalpy : 49.1 kJ/mol
Further explanationThe change in enthalpy in the formation of 1 mole of the elements is called enthalpy of formation
The enthalpy of formation measured in standard conditions (25 ° C, 1 atm) is called the standard enthalpy of formation (ΔHf °)
Based on the principle of Hess's Law, the change in enthalpy of a reaction will be the same even though it is through several stages or ways
Reaction
1. 2C₆H₆ (l) + 15 O₂ (g) → 12 CO₂ (g) + 6 H₂O (g)∆H° = -6271 kJ/mol
Reverse
12 CO₂ (g) + 6 H₂O (g) ⇒ 2C₆H₆ (l) + 15 O₂ (g) ∆H° = 6271 kJ/mol : 2
6CO₂ (g) + 3H₂O (g) ⇒ C₆H₆ (l) + 15/2 O₂ (g) ∆H° = 3135.5 kJ/mol
2. 2 H₂ (g) + O₂ (g) → 2 H₂O (g) ∆H° = -483.6 kJ/mol x 3/2
3H₂ (g) + 3/2O₂ (g) → 3H₂O (g) ∆H° = -725.4 kJ/mol
3. C (s) + O₂ (g) → CO₂ (g) ∆H° = -393.5 kJ/mol x 6
6C (s) + 6O₂ (g) → 6CO₂ (g) ∆H° = -2361 k/j/mol
-------------------------------------------------------------------------------------
6 C (s) + 3 H₂ (g) → C₆H₆ (l) ∆H° = 49.1 kJ/mol
We add up and the same compound that is on different sides we eliminate
What is the energy of a wave if the frequency is 300. Hz
Answer:
[tex]E=1.98\times 10^{-31}\ J[/tex]
Explanation:
Given that,
The frequency of a wave, f = 300 Hz
We need to find the energy of a wave. The formula for the energy of a wave is given by :
E = hf,
Where h is Planck's constant
[tex]E=6.63\times 10^{-34}\times 300\\\\=1.98\times 10^{-31}\ J[/tex]
So, the energy of the wave is [tex]1.98\times 10^{-31}\ J[/tex].
A 1.038 g sample of unknown containing C, H, and O yielded 2.48 g of CO2 and 0.510 g of H2O during combustion analysis. Determine the empirical formula of the compound.
A) C3H3O
B) C6H6O
C) CH3O
D) C6H6O2
E) C2H6O2
Answer:
A. C3H3O
Explanation:
We have the following data:
m = mass of organic compound = 1.038g
Then mass of CO2 is 2.48g
Also mass of H2O is 0.510g
To calculate percentage of carbon = 12 x mass of CO2 x 100/44 x mass of organic compound
This gives us 65.1 percent
Formula to calculate percentage of H=
2 x mass of water x 100/18 x mass of organic compound.
= 2 x 0.510 x 100/18x 10038
This gives 5.4%
Percentage of Oxygen =100-(percentageof carbon +percentageof H)
= 100-(65.1+5.4)
= 100-70.5
= 29.5
We have to calculate emperical formula:
For C = 65.1
65.1/12
= 5.4
= 5.4/1.8
=3
For H=5.4
5.4/1
= 5.4
= 5.4/1.8
=3
For O = 29.5
= 29.5/16
= 1.8
= 1.8/1.8
=1
So the emperical formula of organic compound is given as
C3H3O1
= C3H3O
(The atomic weights of C, H, O are 12,1,16)
Washing machines use a large amount of water. A student suggested that old pairs of stained jeans which have to be washed more frequently should be replaced by new pairs of jeans to conserve water. Which of these statements best describes the suggestion made by the student? Question 9 options: It is not practical because an old pair of jeans needs less water to be washed than a new pair of jeans. It is practical because a huge amount of water can be conserved by this method. It is practical because it is easy to implement. It is not practical because it takes a huge amount of water to produce a new pair of jeans.
Answer:
C |||| It is not practical because it takes a huge amount of water to produce a new pair of jeans
Explanation:
If you're doing flvs then it's C.
Answer:
C!
Explanation:
i got it right on the test UwU
Which unit of measurement would best be used to measure the volume of a points a DROP of water? .
Answer:
milliliter
Explanation:
smallest form of measuring volume from all the available choices
What does this image represent?
Amine group
Carbonyl group
Ether group
Hydroxyl group
Answer:
ether group
Explanation: I looked it up
Determine the number of Au atoms found in 5.18 grams of gold.
A.1.02x1022 atoms
B. 3.84 x 1022 atoms
C.2.13 x 1022 atoms
D.4.58x1022 atoms
1.58 x 1022. atoms
Please let me know
Answer:
1.58× 10²² atoms of Au
Explanation:
Given data:
Mass of gold = 5.18 g
Number of atoms of gold = ?
Solution:
First of all we will calculate the number of moles of gold.
Number of moles = mass/molar mass
Number of moles = 5.18 g/196.96 g/mol
Number of moles = 0.0263 mol
Number of atoms:
Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.
The number 6.022 × 10²³ is called Avogadro number.
1 mole = 6.022 × 10²³ atoms of Au
0.0263 mol × 6.022 × 10²³ atoms of Au / 1mol
0.158× 10²³ atoms of Au
1.58× 10²² atoms of Au
chlorine monobromide ionic or molecular
The indicator phenolphthalein is added to the _____________.
a. Analyte
b. Water
c. Solute
d. Titrant
Answer:
A
Explanation:
I took the test
What is the molality of 6 grams of salt in 10 grams of solution?
Answer:
maalat ang salt
Explanation:
What is The compound with the formula SiCl4
Answer:
silicon tetrachloride or tetrachlorosilane
Why can’t you ice skate on a lake when it is not frozen?
A(n)___ is the smallest neutral unit of two or more atoms held together by a covalent bond?
Answer:
A(n)___ is the smallest neutral unit of two or more atoms held together by a covalent bond?
=>MOLECULE
How many valence electrons are found in P3- ?
Answer:
5 valence elctrons
Explanation:
the outer most orbitals, 3s2 and 3p3 contains 5 electrons, thus valences electrons for P is 5
Blood takes about 1.55 s to pass through a 2.00 mm long capillary. If the diameter of the capillary is 5.00 μm and the pressure drop is 2.45 kPa, calculate the viscosity ???? of blood. Assume laminar flow.
Answer:
The viscosity [tex]\mathbf{\eta = 7.416 \times 10^{-4} \ N.s/m^2}[/tex]
Explanation:
From the given information:
Time t = 1.55 s
The radius of capillary = 5.00 μm /2
The pressure drop ΔP = 2.45 kPa
The length of the capillary = 2.00 mm
∴
The viscosity of the blood flow can be calculated by using the formula:
[tex]\eta = \dfrac{r^2 \Delta P }{8Lv}[/tex]
where;
v = L/t
Then;
[tex]\eta = \dfrac{r^2 \Delta P }{8L(\dfrac{L}{t})}[/tex]
[tex]\eta = \dfrac{(\dfrac{5 \times 10^{-6} \ m}{2})^2(2.45 \times 10^3 \ Pa) }{8(2.0 \times 10^{-3} \ m ) (\dfrac{2.0 \times 10^{-3} \ m }{1.55 \ s })}[/tex]
[tex]\eta = 7.416 \times 10^{-4} \ Pa.s[/tex]
To (N.s/m²)
[tex]\mathbf{\eta = 7.416 \times 10^{-4} \ N.s/m^2}[/tex]
What is the mole fraction of water in a solution that contains 8.0 mol of ethanol (C2H5OH) and 1.6 mol of water?
Answer:
the mole fraction of water in a solution is 0.17
Explanation:
The computation of the mole fraction of water in a solution is shown below:
Given that
Ethanol be 8.0 mol
And, the water be 1.6 mol
Based on the above information, the mole fraction of water in a solution is
= Water ÷ (Water + ethanol)
= 1.6 mol ÷ (1.6 mol + 8.0 mol)
= 1.6 mol ÷ 9.6 mol
= 0.17
Hence, the mole fraction of water in a solution is 0.17
Other than the starting material, 2-methylcyclohexanol, what base or bases are present in the dehydration reaction mixture to participate in proton transfers?
a) H2PO4- only
b) H2O and H2PO4-
c) H2O and HSO4-
d) H2O only
Answer:
c) H2O and HSO4-
Explanation:
The dehydration of 2-methylcyclohexanol occurs in the presence of H2SO4. Recall that acids are proton donors in solution; the equilibrium shown below is then set up,
H2SO4(aq) + H2O(l) ⇄H3O^+(aq) + HSO4^-(aq)
The species H2O and HSO4- are two proton acceptors in the system. According to the Brownstead- Lowry definition, a base is a proton acceptor in solution.
Hence H2O and HSO4- are bases present in the dehydration of 2-methylcyclohexanol.
Part A Calculate the [H3O+] of the following polyprotic acid solution: 0.300M H3PO4. Express your answer using two significant figures.
Part B Calculate the pH of this solution.
Express your answer using one decimal place.
Part C Calculate the [H3O+] and pH of the following polyprotic acid solution: 0.310M H2C2O4.
Express your answer using two significant figures.
Part D Calculate the pH of this solution.
Express your answer using two decimal places.
Answer:
A. [H₃O⁺] = 0.900 M
B. pH = 0.0 to one decimal place
C. [H₃O⁺] = 0.620 M
D. pH = 0.21 to two decimal places
Explanation:
A. Equation for the complete dissociation of H₃PO₄ is given below:
H₃PO₄(s) + 3H₂O(l) -----> PO₄³⁻(aq) + 3H₃O⁺(aq)
From the equation of reaction, one mole of H₃PO₄ produces 3 moles of H₃O⁺
Therefore, [H₃O⁺] = 3 * 0.300M = 0.900 M
B. pH = -log[H₃O⁺]
pH = - log(0.900)
pH = -log (9 * 10⁻¹)
pH = 0.0 to one decimal place
C. Equation for the complete dissociation of H₂C₂O₄ is given below:
H₂C₂O₄(s) + 2H₂O(l) ----> C₂O₄⁻(aq) + 2H₃O⁺
From the equation of reaction, one mole of H₂C₂O₄ produces 3 moles of H₃O⁺
Therefore, [H₃O⁺] = 2 * 0.310 M = 0.620 M
D. pH = -log[H₃O⁺]
pH = -log(0.620)
pH = -log(0.62 * 10⁻¹)
pH = 0.21 to two decimal places
The concentration of [[tex]\rm H_3O^+[/tex]] has been 0.9 M, and the pH has been 0.045.
The polyprotic acid has been able to donate more than one proton in an acid-base reaction.
The balanced chemical reaction can be:
[tex]\rm H_3PO_4\;+\;3\;H_2O\;\rightarrow\;PO_4^3^-\;+\;3\;H_3O^+[/tex]
(a) According to the equation, 1 mole of [tex]\rm H_3PO_4[/tex] gives 3 moles of hydronium ions. The molarity has been defined as moles per liter. Assuming the volume of reaction to be 1 liter.
1 mole [tex]\rm H_3PO_4[/tex] = 1 M [tex]\rm H_3PO_4[/tex]
1 mole [tex]\rm H_3PO_4[/tex] = 3 moles [[tex]\rm H_3O^+[/tex]]
0.3 mole [tex]\rm H_3PO_4[/tex] = 3 [tex]\times[/tex] 0.3 moles [[tex]\rm H_3O^+[/tex]].
0.3 mole [tex]\rm H_3PO_4[/tex] = 0.9 moles [[tex]\rm H_3O^+[/tex]]
The concentration of [[tex]\rm H_3O^+[/tex]] has been 0.9 mole/L, or 0.9 M.
(b) pH of the solution can be defined as:
pH = -log [[tex]\rm H_3O^+[/tex]]
pH = -log (0.9)
pH = 0.045
The pH of the solution has been 0.045.
(c) The polyprotic acid have the balanced equation:
[tex]\rm H_2C_2O_4\;+\;2\;H_2O\;\rightarrow\;C_2O_4^-\;+\;2\;H_3O^+[/tex]
According to the equation, 1 M [tex]\rm H_2C_2O_4[/tex] gives 2 M [tex]\rm H_3O^+[/tex].
The concentration of hydronium ions from 0.310 M [tex]\rm H_2C_2O_4[/tex] has been:
1 M [tex]\rm H_2C_2O_4[/tex] = 3 M [tex]\rm H_3O^+[/tex]
0.310 M [tex]\rm H_2C_2O_4[/tex] = 2 [tex]\times[/tex] 0.310 moles [[tex]\rm H_3O^+[/tex]]
0.310 M [tex]\rm H_2C_2O_4[/tex] = 0.62 M [[tex]\rm H_3O^+[/tex]].
The [[tex]\rm H_3O^+[/tex]] concentration of the solution has been 0.62 M.
(d) pH of the solution can be defined as:
pH = -log [[tex]\rm H_3O^+[/tex]]
pH = -log (0.62)
pH = 0.20
The pH of the solution has been 0.20.
For more information about the pH of the solution, refer to the link:
https://brainly.com/question/1265333
How something works is related to its structure
Answer:
Forms and Functions
Explanation:
It refers to the direct relationship between the structure of a thing and the way it functions.
What is the mole fraction of each component if 3.9 g of benzene (C6H6) is dissolved in 4.6 g of toluene (C7H8)
Answer:
Step 1 of 6
(a)
The mass of benzene is  , so calculate the moles of benzene as follows:

The mass of toluene is, so calculate the moles of toluene as follows:

Now, calculate the mole fraction as follows:


Therefore, the mole fraction of benzene and toluene is  and  respectively.
Step 2 of 6
(b)
The formula to calculate the partial pressure is as follows:

Here,  is the partial pressure of benzene,  is the vapour pressure of pure benzene and  is the mole fraction of benzene.
Vapour pressure of pure benzene at  is.
Substitute the values in the equation as follows:

Therefore, the partial pressure is  .
Step 3 of 6
(c)
Vapor pressure of the solution at 1 atm is  .
When the total pressure of the vapour pressure of the mixture is  at a temperature, then, the solution boils. It corresponds to the boiling point of the solution.
Calculate the total pressure of the solution at  as follows:

Since, the total pressure is less than the atmospheric pressure, the solution will not boil at  .
Calculate the total pressure of the solution at  as follows:

Since, the total pressure is greater than the atmospheric pressure, the solution will boil at  .
Therefore, the boiling point of the solution is  .
Step 4 of 6
(d)
Mole fraction of benzene at  is calculated as follows:

Mole fraction of toluene at  is calculated as follows:

Therefore, the mole fractions of benzene and toluene are  and  respectively.
Step 5 of 6
(e)
Vapor pressure of benzene at  is  .
Partial pressure of benzene is calculated as follows:

Vapor pressure of toluene at  is  .
Partial pressure of toluene is calculated as follows:

Step 6 of 6
Weight composition of the vapour that is in equilibrium with the solution is calculated as follows:

Weight composition of the vapour that is in equilibrium with the solution is calculated as follows:

Explanation:
mark me as brainliest
Look at the picture below. Name the isotope
Calcium-19
Calcium-39
Potassium-20
Potassium-39
Which of these compounds do not have a pH dependent solubility at less than pH 7.00?
Answer:
tbh idekkk
Explanation:
Which pair of elements would you expect to have similar properties?
Li and Fe
At and F
F and o
Ge and As
Show by calculation which process produces more energy per gram of material reacting
The sun shines more directly near the equator, bringing more warmth there. In polar regions the sun shines at angles such that
they get little or no sunlight during the winter, causing colder temperatures. Predict how these differences in temperature create a
movement in the atmospheric gases and distribute heat energy from the sun across the planet.
A)
B)
As air in one region diffuses, it becomes less condensed than the
surrounding air and begins to rise and draws more air along.
As air in one region warms, it becomes less dense than the surrounding air
and begins to rise and draws more air in underneath.
As air in one region warms, it becomes less nebulous than the surrounding
air and begins to descend and draws more air in with it.
As air in one region cools, it becomes less compact than the surrounding
air and begins to accelerate and draws more air in supportively.
C)
D)
Answer:Because the Earth is round and not flat, the Sun's rays don't fall evenly on the land and oceans. The Sun shines more directly near the equator bringing these areas more warmth. However, the polar regions are at such an angle to the Sun that they get little or no sunlight during the winter, causing colder temperatures.
Explanation:
What mass of a solution labeled 6.3% sucrose (C12H22O11, 342 g/mol) by mass contains 11.0 g of sucrose?
Answer:
174.6g of solution contains the 11.0g of sucrose
Explanation:
A solution of 6.3% by mass of sucrose contains 6.3g of sucrose in 100g of solution, that is, 6.3g of sucrose / 100g of solution.
As we want to find the mass contains 11.0g of sucrose, we can write:
11.0g of sucrose * (100g of solution / 6.3g of solution) =
174.6g of solution contains the 11.0g of sucrosea sample of lead had a mass of 150 g. The molar mass of lead is 207.19 g. How many moles of lead does the sample contain?
Answer:
Explanation:
no of moles=given mass/molar mass
no of moles=150 g/207.19
no of moles=0.72
We will use dimensional analysis to answer this question.
[tex]150 g * \frac{1 g}{207.19 mol} = 0.724 mol[/tex]
The answer is 0.724 mol.
In the third century B.C., King Hieron of Syracuse asked the famous mathematician Archimedes to determine if his crown was made of pure gold. This was a puzzling problem for Archimedes-he knew how to measure the weight of the crown, but how could he measure the volume? Archimedes solved the problem when he got into his bath and noticed the water spilling over the sides of the tub. He realized that the volume of the displaced water must be equal to the volume of the object placed into the water. Archimedes was so excited by. his discovery that he jumped out of the bath and ran through the streets shouting "Eureka!" a. How can you tell if a crown is made of solid gold? b. Gold is one of the densest substances known, with a density of 19.3 g/mL. If the gold in the crown was mixed with a less-valuable metal like bronze or copper, how would that affect its density? c. What is the relationship between the object density, the liquid density, and the tendency of the object to float? d. From the experimental results obtained by you in the lab of the density of the liquid and the object, could the object float in that liquid? Explain.
Answer:
See explanation
Explanation:
a. I can conclusively tell if the crown was made of gold by measuring its density. First the mass of the crown is measured on a weighing balance. The crown is now put into a given volume of water and the volume of water displaced is accurately measured. The density of the crown is computed as mass/volume of fluid displaced. If the density of the crown is 19.3 g/mL, then it is made of solid gold.
b) When less valuable metals such as bronze or copper is mixed with gold in the crown, the density of the crown decreases and the crown becomes more brittle.
c) An object will float in a liquid when the density of the object is less than the density of the liquid. Hence the tendency of an object to float in a liquid depends on the density of the object and the density of the liquid.
d) Even though i do not know the results from your experiment but as regards the decision as to whether the object will float in the given liquid or not, reference must be made to the measured density of the object as well as the given density of the liquid. If the object is less dense (from values of density obtained from the experiment) than the liquid, then the object will float in the liquid and vice versa.
What is the change in the internal energy of a system that does 100 joules of
work and absorbs 1,000 joules of heat?
Answer:900j
Explanation:
Calculate the following quantity: volume of 1.58 M calcium chloride that must be diluted with water
to prepare 994 mL of a 6.20 x 10^-2 M chloride ion solution.