Complete Question
Sodium carbonate, Na2CO3(s), can be prepared by heating sodium bicarbonate, NaHCO3(s).
2NaHCO3(s) ------> Na2CO3(s) + CO2(g) + H2O(g) Kp = 0.23 at 100oC
If a sample of NaHCO3 is placed in an evacuated flask and allowed to achieve equilibrium at 100oC, what will the total gas pressure be?
Answer:
The value is [tex]P_T = 0.959 \ atm [/tex]
Explanation:
From the question we are told that
The equation is
[tex]2NaHCO_3_{(s)} \rightarrow Na_2CO_3_{(s)} + CO2_{(g)} + H2O_{(g)}[/tex]
Generally the equilibrium partial pressure is mathematically represented as
[tex]K_p = P_{CO_2} + P_{H_2O}[/tex]
Here
[tex] P_{CO_2} \ and \ P_{H_2O}[/tex] are partial pressures of [tex] CO_2 \ and \ H_2O [/tex] gases
Note: when writing the formula for equilibrium partial pressure we consider only the gas in the reaction
Let assume that
[tex]P_{CO_2} = a[/tex]
Generally [tex]P_{CO_2} = P_{H_2O}[/tex] since they are both products of the reaction
So
[tex]K_p = a^2 [/tex]
From the question we are told that [tex]K_p = 0.23 [/tex]
So
[tex] 0.23= a^2 [/tex]
=> [tex] a = \sqrt{0.23} [/tex]
=> [tex] a = \sqrt{0.23} [/tex]
=> [tex] a = 0.4796 \ atm [/tex]
So
[tex]P_{CO_2} = 0.4796 \ atm[/tex]
and
[tex]P_{H_2O} = 0.4796 \ atm [/tex]
So the total pressure is
[tex]P_T = 0.4796 + 0.4796[/tex]
=> [tex]P_T = 0.959 \ atm [/tex]
Enter your answer in the provided box. A sample of an unknown gas effuses in 11.1 min. An equal volume of H2 in the same apparatus under the same conditions effuses in 2.42 min. What is the molar mass of the unknown gas
Answer: The molar mass of the unknown gas is 9 g/mol
Explanation:
From Graham's law of effusion rates, the rate of effusion of a gas is inversely proportional to the square root of its molar mass.
[tex]\frac{rate_1}{rate_2}=\sqrt{\frac{M_2}{M_1}} [/tex]
[tex]rate=\frac{volume}{time} [/tex]
Rate is volume effused per unit time. Since, the volumes are same, the formula could be written as:
[tex]\frac{t_B}{t_A}=\sqrt{\frac{M_B}{M_A}}[/tex]
Putting the values in the formula:
[tex]\frac{2.42min}{11.1min}=\sqrt{\frac{M_{H_2}}{M_A}} [/tex]
[tex]\frac{2.42min}{11.1min}=\sqrt{\frac{2}{M_A}} [/tex]
Squaring both sides:
[tex]\frac{2}{M_A}=0.218[/tex]
[tex]M_A=9g/mol[/tex]
The molar mass of the unknown gas is 9 g/mol
Someone plz hello me ASAP it would be appreciated on question 7 btw
Answer:
Kinetic Energy is the correct Answer.
Explanation:
At the highest point on the roller coaster (assuming it has no velocity), the object has a maximum quantity of gravitational potential energy. As the object begins moving down to the bottom, its gravitational potential energy begins to decrease and the Kinetic Energy starts to increase.
Which is one way that minerals crystallize from materials dissolved in water?
from the air
from solutions that evaporate
from hot water solutions when water boils
from the soil
Answer:
the second answer its science behind it
Answer:
b
Explanation:
The energy required to ionize boron is 801 kJ/mol. You may want to reference (Pages 93 - 98) Section 2.5 while completing this problem. Part A What minimum frequency of light is required to ionize boron
Answer:
The frequency is [tex]f = 2,01 * 10^{15} \ Hz [/tex]
Explanation:
From the question we are told that
The energy required to ionize boron is [tex]E_b = 801 KJ/mol[/tex]
Generally the ionization energy of boron pre atom is mathematically represented as
[tex]E_a = \frac{E_b}{N_A}[/tex]
Here [tex]N_A[/tex] is the Avogadro's constant with value [tex]N_A = 6.022*10^{23}[/tex]
So
[tex]E_a = \frac{801}{6.022*10^{23}}[/tex]
=> [tex]E_a = 1.330 *10^{-18} \ J/atom [/tex]
Generally the energy required to liberate one electron from an atom is equivalent to the ionization energy per atom and this mathematically represented as
[tex]E = hf = E_a[/tex]
=> [tex] hf = E_a[/tex]
Here h is the Planks constant with value [tex]h = 6.626 *10^{-34}[/tex]
So
[tex]f = \frac{1.330 *10^{-18}}{ 6.626 *10^{-34}}[/tex]
=> [tex]f = 2,01 * 10^{15} \ Hz [/tex]
explain the reason each step of the separation is performed with three portions of the solvent rather than with a single poriton of solvent
Answer:
Several extractions is more effective than a single extraction.
Explanation:
When extraction is carried out multiple times, for instance, in this case, the extraction was carried out with three portions of the solvent rather than with just a single portion of the solvent, the amount of material left in the residue will be lower, because the extraction is more complete.
Several extractions with smaller volumes of solvent are more effective than a single extraction with a large volume of solvent.
A gaseous mixture contains 441.0 Torr H2(g), 387.3 Torr N2(g), and 74.5 Torr Ar(g). Calculate the mole fraction, ????, of each of these gases.
????H2=
????N2=
????Ar=
Answer:
XH₂ = 0.4885
XN₂ = 0.4290
XAr = 0.0825
Explanation:
Step 1: Given data
Partial pressure of H₂ (pH₂): 441.0 TorrPartial pressure of N₂ (pN₂): 387.3 TorrPartial pressure of Ar (pAr): 74.5 TorrStep 2: Calculate the total pressure (P)
The total pressure is equal to the sum of the partial pressures of all the gases.
P = pH₂ + pN₂ + pAr = 441.0 Torr + 387.3 Torr + 74.5 Torr = 902.8 Torr
Step 3: Calculate the mole fraction (X) of each gas
We will use the following expression.
Xi = pi / P
where,
Xi: mole fraction of the gas i
pi: partial pressure of the gas i
P: total pressure
XH₂ = pH₂ / P = 441.0 Torr / 902.8 Torr = 0.4885
XN₂ = pN₂ / P = 387.3 Torr / 902.8 Torr = 0.4290
XAr = pAr / P = 74.5 Torr / 902.8 Torr = 0.0825
Question: Can a penny dropped from a building kill a pedestrian below?
Hypothesis:
Controls:
Independent variable:
Dependent variable:
Conclusion:
Answer:
Hypothesis: IF a penny is dropped from a building, THEN it would kill a pedestrian below
Controls: Same building, Same distance
Independent variable: Penny
Dependent variable: Pedestrian's death
Conclusion: The hypothesis is rejected
Explanation:
- The hypothesis is a testable explanation to an observed problem or asked question. Based on the cientific question in this question, a possible hypothesis will be: IF a penny is dropped from a building, THEN it would kill a pedestrian below
- Independent variable is the variable that is changed or manipulated in an experiment. In this case, the PENNY is the independent variable
- Dependent variable is the variable that responds to the change made to the independent variable. It is the measured variable. In this case, the dependent variable is the DEATH OF PEDESTRIANS.
- Controls are those variables that is kept constant or unchanged throughout the experiment. The controls in this experiment are: Same building, Same distance of throw etc.
- The conclusion is whether the hypothesis is accepted or not depending on the result of the experiment conducted. In this case, the hypothesis will be rejected if the penny doesn't kill a pedestrian
A certain first-order reaction has a rate constant of 2.10×10−2 s−1 at 19 ∘C. What is the value of k at 58 ∘C if Ea = 82.0 kJ/mol ?
Answer:
K₂ = 1.12s⁻¹
Explanation:
Based on Arrhenius equation:
ln K₂/K₁ = -Ea/R (1/T₂ - 1/T₁)
Where K is rate constant,
R is gas constant (8.314J/molK),
T is absolute temperature (In K) Of 1, initial state and 2, final state.
ln K₂/K₁ = -Ea/R (1/T₂ - 1/T₁)
ln K₂/2.10x10⁻²s⁻¹ = -82000J/mol/8.314J/molK (1/(273.15 + 58) - 1/(273.15 + 19))
ln K₂ / 2.10x10⁻²s⁻¹ = 3.976
K₂ / 2.10x10⁻²s⁻¹ = 53.3
K₂ = 1.12s⁻¹
The molar mass of gallium (Ga) is 69.72 g/mol.
Calculate the number of atoms in a 27.2 mg sample of Ga.
Write your answer in scientific notation using three significant figures.
atoms Ga
Answer:
2.35 x 10²⁰ atoms Ga
Explanation:
After converting from mg to g, use the molar mass as the unit converter to convert to moles. Then using Avogadro's number, 6.022 x 10²³ convert from moles to atoms of Ga.
[tex]27.2mgGa*\frac{1g}{1000mg} *\frac{1 mol Ga}{69.72gGa} *\frac{6.022*10^2^3 atoms Ga}{1 molGa} = 2.349 * 10^2^0 atoms Ga[/tex]
Then round to 3 significant figures = 2.35 x 10²⁰ atoms Ga.
The number of atoms in 27.2 mg sample of Ga is 2.35 × 10²⁰ atoms
StoichiometryFrom the question, we are to calculate the number of atoms in a 27.2 mg sample of Ga.
First, we will determine the number of moles of Ga present
Using the formula,
[tex]Number\ of\ moles = \frac{Mass}{Molar\ mass} [/tex]
Mass = 27.2 mg = 0.0272 g
Molar mass = 69.72 g/mol
Then,
[tex]Number\ of\ moles \ of\ Ga = \frac{0.0272}{69.72} [/tex]
[tex]Number\ of\ moles \ of\ Ga = [/tex] 0.000390132 moles
Now, for the number of atoms present
From the formula
Number of atoms = Number of moles × Avogadro's constant
Then,
Number of Ga atoms = 0.000390132 × 6.022×10²³
Number of Ga atoms = 2.35 × 10²⁰ atoms
Hence, the number of atoms in 27.2 mg sample of Ga is 2.35 × 10²⁰ atoms
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3. Does matter increase in
mass when mixed with
another substance?
a Yes
b. No
Answer:
b. No
Explanation:
The question above is related to "The Law of Conservation of Mass." This law states that mass is neither created nor can it be destroyed. Even if a particular matter will be mixed with another substance or it undergoes chemical reaction, the mass of the matter will remain the same. Even with a change in phase, the mass of the matter will remain the same.
The density of wind-packed snow is estimated to be 0.35 g/cm^3. A flat roof that is 35 by 43 feet has 28 inches of snow on it. How many pounds of snow are on the roof?
Answer:
There are 76728.2 pounds of snow on the roof
Explanation:
To determine how many pounds of snow are on the roof,
First we will determine the mass of the snow in grams.
From the question,
Density of snow = 0.35 g/cm³
From
Density = Mass / Volume
To determine the mass, we will first find the volume.
From the question, a flat roof that is 35 by 43 feet has 28 inches of snow on it, that is, the height of the snow on the roof is 28 inches.
Area of the roof = 35 ft × 43 ft = 1505 ft²
Volume of the snow = Area of the roof × Height of the snow
Height of the snow = 28 inches
12 inches = 1 foot
∴ 28 inches = 28/12 feet = 2.3333 ft
Hence,
Volume of the snow = 1505 ft² × 2.3333 ft = 3511.62 ft³
Volume of the snow = 3511.62 ft³
This is the volume of the snow in cubic feet
Now, we will convert cubic feet (ft³) to cubic centimeter (cm³)
1 ft = 30.48 cm
and 1 ft³ = 30.48³ cm³ = 28316.84659 cm³.
If 1 ft³ = 28316.84659 cm³
∴ 3511.62 ft³ will be 3511.62 × 28316.84659 cm³ = 99438004.83 cm³
Hence, Volume of snow = 99438004.83 cm³
Now, we can determine mass of snow in grams
From
Density = Mass / Volume
Mass = Density × Volume
Mass = 0.35 g/cm³ × 99438004.83 cm³
Mass = 34803301.69 g
Now, we will convert the mass from grams to pounds
1 pound = 453.592 grams
If 453.592 grams = 1 pound
Then, 34803301.69 g will be 34803301.69 / 453.592 pounds = 76728.2 pounds
Hence, there are 76728.2 pounds of snow on the roof.
What is the momentum of a 1kg ball moving at 5m/s?
Answer:
5Ns
momentum= mass *velocity
=1*5
=5Ns
In the ionic compound KCL, which ion is the cation, and which is the anion? PLEASE HELP
Answer:
Potassium chloride, KCl , is an ionic compound formed by the electrostatic force of attraction that holds the potassium cations and the chlorine anions together
Explanation:
Two fruit flies that are heterozygous for body color and eye color are crossed. Brown body color is dominant to black body color. Red eye color is dominant to brown eye color.
Determine the genotypes of offspring 1-8.
1
2
3
4
5
6
7
8
A 4-column table has 4 rows. The labels of the columns are Upper B Upper E, Upper B e, b Upper E, b e. The labels of the rows are Upper B Upper E, Upper B e, b Upper E, Upper B b Upper E e. The first column has entries 1, Upper B Upper B Upper E e, 4, Upper B b Upper E e. The second column has entries Upper B Upper B Upper E e, 3, Upper B b Upper E e, 7. The third column has entries Upper B b Upper E Upper E, Upper B b Upper E e, 5, b b Upper E e. The fourth column has entries 2,Upper B b e e, 6, 8.
Answer:
the answer is simple
Explanation:
jnnn B upper up of the eye color
Answer:
1. BBEE
2. BbEe
3. BBee
4. BbEE
5. bbEE
6. bbEe
7. Bbee
8.bbee
A gas has a volume of 300 mL and a pressure of 2 atm. What volume will the gas occupy when the pressure is
increased to 7 atm (total)?
Answer:
The answer is 85.71 mLExplanation:
The new volume can be found by using the formula for Boyle's law which is
[tex]P_1V_1 = P_2V_2[/tex]
where
P1 is the initial pressure
P2 is the final pressure
V1 is the initial volume
V2 is the final volume
Since we are finding the new volume
[tex]V_2 = \frac{P_1V_1}{P_2} \\[/tex]
We have
[tex]V_2 = \frac{300 \times 2}{7} = \frac{600}{7} \\ = 85.714285...[/tex]
We have the final answer as
85.71 mLHope this helps you
20 POINTS PLEASE ANSWER ASAP!!!!
Why is calcium (Ca) in group 2, period 4 on the periodic table?
A Calcium, like all group 2 elements, is nonreactive and a gas at room temperature.
B Calcium, like all period 4 elements, is nonreactive and a gas at room temperature,
C Calcium, like all group 2 elements, is reactive and a solid at room temperature.
D. Calcium, like all period 4 elements, is reactive and a solid at room temperature.
Calcium (Ca) is in group 2 and period 4 on the periodic table be because Calcium has 2 valence electrons and 4 electron shell. Thus, calcium is a metal like all other group 2 element.
The correct answer to the question is Option C. Calcium, like all group 2 elements, is reactive and a solid at room temperature.
Calcium is a group 2 element majorly because it has 2 valence electrons. It is also in period 4 because it has 4 electron shells.
Being a group 2 element, calcium is a solid at room temperature and also reactive. All elements in the group 2 are metals.
There are other elements in period 4 which are not solid. For example krypton is an element in period 4 and it is a gas and not reactive.
From the above information, we can conclude that the correct answer to the question is:
Option C. Calcium, like all group 2 elements, is reactive and a solid at room temperature.
See attached image
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Which of the following reactions will proceed as drawn below? (Yes or No)
Answer:
i wish i could help but t know either so i wish you luck for an answer once again truly sorry don'
Explanation:
i am sorry but i do not know :(
Is nuclear fission exothermic or endothermic? Explain your answer.
Answer:
Exothermic
Explanation:
Nuclear fission means splitting, so there is a lot of energy being released.
Convert
12 x 1025 kg/mL to fg/cm3
Answer:
[tex]1.2x10^{38}\frac{fg}{cm^3}[/tex]
Explanation:
Hello there!
In this case, for such unit conversion we need to realize that 1 kg is equal to 1000 g, 1 g is equal to 1x10⁹ and 1 mL equals 1 cm³, therefore we apply:
[tex]12x10^{25}kg*\frac{1000g}{1kg} *\frac{1x10^9fg}{1g} *\frac{1mL}{1cm^3} \\\\1.2x10^{38}\frac{fg}{cm^3}[/tex]
Best regards!
3. Which of the following molecules would want except to have a nonpolar covalent bond
Answer:
polar bonds are caused by different kind of atoms, because almost every atoms have different powers to attract electrons.
the answer will be the two same atoms, F2
Which of the following is NOT an example of deposition?
sand dune
river delta
cave crystal
valley
This science btw
Answer:
Cave Crystal
Explanation:
I believe it's cave crystal because sand dunes, river deltas, and valleys are all examples of deposition.
Calculate the pH of a 0.02 M solution of ascorbic acid ( K a1 = 7.9 × 10 –5; K a2 is 1.6 × 10 –12).
a.
2.9
b.
8.2
c.
11.8
d.
11.1
e.
5.8
Answer:
C
Explanation:
ou are given a solution containing a pair of enantiomers (A and B). Careful measurements show that the solution contains 98% A and 2% B. What is the ee of this solution
Complete Question
You are given a solution containing a pair of enantiomers (A and B). Careful measurements show that the solution contains 98% A and 2% B. What is the enantiomeric excess?
Answer:
The value is [tex]k = 96 %[/tex]
Explanation:
From the question we are told that
The percentage of enantiomer A is A = 98%
The percentage of enantiomer B is B = 2%
Generally the enantiomeric excess is mathematically represented as
[tex]k = \frac{A -B}{A+B} * 100[/tex]
=> [tex]k = \frac{98 -2}{98+2} * 100[/tex]
=> [tex]k = 96 %[/tex]
Suppose you produce 0.0451 g of N 2 gas with a volume of 0.0413 L and a pressure of 0.991 atm at 298 K. Based on the experimental data, what is the value of the gas constant R ?
Ideal gas law is valid only for ideal gas not for vanderwaal gas. Therefore, value of the gas constant R is 0.0821LatmK⁻¹ when volume is 0.0413 L.
What is ideal gas equation?
Ideal gas equation is the mathematical expression that relates pressure volume and temperature.
Mathematically the relation between Pressure, volume and temperature can be given as
PV=nRT
where,
P = pressure of nitrogen gas = 0.991 atm
V= volume of nitrogen gas =0.0413 L
n =number of moles of nitrogen gas = given mass ÷Molar mass
=0.0451 g ÷28
=0.0016mol
T =temperature of nitrogen gas =298 K
R = Gas constant =?
0.991 atm×0.0413 L=0.0016×R×298 K
R=0.0821LatmK⁻¹
Therefore, value of the gas constant R is 0.0821LatmK⁻¹.
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he concentration of H2S in a saturated aqueous solution at room temperature is approximately 0.1 M. Ka1=8.9x10-8 Ka2=1.0x10-19 Calculate the pH of the solution in 2 sig figs
Answer:
PH = 4.0
Explanation:
We are given;
Ka1 = 8.9 × 10^(-8)
Ka2 = 1.0 × 10^(-19)
From the 2 values of K given above, we can see that Ka2 is far smaller than Ka1.
Thus, Positive hydrogen ion (H+) will be majorly formed from first dissociation which is Ka1.
Now, the breakdown of the H2S solution is;
H2S⇌[H+] + [HS−]
Thus;
Ka1 = [[H+] × [HS2^(-)]]/(H2S)
HS2^(-) also has a positive hydrogen ion.
Thus, we can rewrite as;
Ka1 = [[H+] × [H+]]/(H2S)
Ka1 = (H+)²/(H2S)
Concentration of H2S is given as 0.1M. Thus;
8.9 × 10^(-8) = (H+)²/0.1
(H+)² = 0.1 × 8.9 × 10^(-8)
(H+) = √(0.1 × 8.9 × 10^(-8))
(H+) = 0.00009433981
Now, PH is gotten from;
PH = -log (H+)
Thus;
PH = -log 0.00009433981
PH ≈ 4.0
A major component of gasoline is octane (C8H18). When octane is burned in air, it chemically reacts with oxygen gas (O2) to produce carbon dioxide CO2 and water H2O. What mass of carbon dioxide is produced by the reaction of 7.58 g of octane? Please explain the answer to me like I'm five, I want to understand but the content makes no sense.
Answer:
Mass = 23.232 g
Explanation:
Given data:
Mass of C₈H₁₈ = 7.58 g
Mass of CO₂ produced = ?
Solution:
Chemical equation:
2C₈H₁₈ + 25O₂ → 16CO₂ + 18H₂O
Number of moles of octane:
Number of moles = mass/molar mass
Number of moles = 7.58 g/ 114.23 g/mol
Number of moles = 0.066 mol
Now we will compare the moles of CO₂ with octane from balance chemical equation.
C₈H₁₈ : CO₂
2 : 16
0.066 : 16/2×0.066 = 0.528
Mass of CO₂ produced:
Mass = number of moles × molar mass
Mass = 0.528 mol × 44 g/mol
Mass = 23.232 g
After heating the solution, you decant the liquid and wash the remaining solid with distilled water. What you are removing by this washing?
Answer:
The solvent
Explanation:
After the solid is recoverd by decanting the liquid, some solvent particles may still adhere to the solid.
In order to remove the solvent that may have adhered to the solid completely , the solid is washed before it is now dried.
In order to remove the remaining liquid present the solid material.
We are washing the solid in order to remove the liquid particles that is attached to the solid material with the help of water. Water is a universal solvent that dissolve large number of solutes in it.
Water removes the liquid from the solid by attaching with that liquid or dissolving in it so that's why we use water for washing a solid in order to remove the impurities from the solid material in which it is placed.
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When methylcyclobutane is treated with chlorine gas and heated, the total number of monochlorinated products, including stereoisomers, is
Answer:
5
Explanation:
The image attached shows the different monochlorination products obtained when chlorine gas is heated with methylcyclobutane.
We must keep in mind that the reaction occurs by free radical mechanism as shown in the image attached. The proportion in which the products are formed depends on the stability of the free radical intermediate leading to that particular product.
Image credit: askiitians
what is the relationship between the atomic number and the melting and boiling point
Answer:
As the atomic number of elements increases, the melting point increases because there are more electrons around the nucleus, which creates a stronger negatively-charged force. With stronger forces, the melting point rises. 3. Non-metals usually have low melting points.
Explanation:
The melting point rises as the atomic number of elements increases because there are more electrons surrounding the nucleus, creating a stronger negatively charged force. The melting point rises as the forces become stronger.
What is nucleus?The nucleus is made up of protons, which are positively charged, and neutrons, which are electrically neutral. Quarks are particles that make up protons and neutrons. The nucleus (plural, nuclei) is a positively charged region in the atom's center. It is made up of two types of subatomic particles that are tightly packed together. Protons, which have a positive electric charge, and neutrons, which have a neutral electric charge, are the particles. The nucleus is the most important component of the cell (plural: nuclei). It is derived from a Latin word that means "nut kernel." Definition of Nucleus: A nucleus is a double-membraned eukaryotic cell organelle that contains genetic material.To learn more about nucleus, refer to:
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Question 5 of 5
Which two phrases describe the nature of an electromagnetic force?
O A. Acts only when objects touch each other
B. Produced by interactions between magnetic objects
O c. Not a fundamental force of nature
O D. Produced by interactions between electrically charged objects
Answer:
I think it's A and D
Explanation:
I'm not sure if it's right
Answer:
The answer is B and D
Explanation:
trust fr