Answer:
a) 1.392 x 10^6 g/cm^3
b) 8.69 x 10^7 lb/ft^3
Explanation:
mass of the star m = 2.0 x 10^36 kg
radius of the star (assumed to be spherical) r = 7.0 x 10^5 km = 7.0 x 10^8 m
The density of substance ρ = mass/volume
The volume of the star = volume of a sphere = [tex]\frac{4}{3}\pi r^{3}[/tex]
==> V = [tex]\frac{4}{3}*3.142*(7.0*10^8)^{3}[/tex] = 1.437 x 10^27 m^3
density of the star ρ = (2.0 x 10^36)/(1.437 x 10^27) = 1.392 x 10^9 kg/m^3
in g/cm^3 = (1.392 x 10^9)/1000 = 1.392 x 10^6 g/cm^3
in lb/ft^3 = (1.392 x 10^9)/16.018 = 8.69 x 10^7 lb/ft^3
1.) Given 30 grams of CO2, how many moles of CO2 would you have? How many individual molecules of CO2 is that?
2., Given 22 Grams of NaCl, How many moles of Nacl would you have? How many individual molecules of NaCl is that?
3.) Given 50 grams of ammonia NH3, How many moles of NH3 would you have? How many Molecules of NH3 is that?
Answer:
1a) .68 moles 1b)4.1E-23 molecules.
2a) .37 moles 2b) 2.27E-23 molecules
Explanation:
1a) CO2 is equal to 44 grams (C→12 grams,O→16 grams[·2]) .30g/44g is .68 moles.
1b) multiply 1A by advogadros number (6.022E-23)
2a) NaCl is 58 grams. 22/58 is .37 moles.
2b) multiply 2A by advogadros number.
you'd answer #3 the same way #1 and #2
The branch of science that deals with chemicals and bonds are called chemistry. The moles are units to calculate the quantity required to use the element.
The correct answer is mentioned below.
What are moles?The mole is the base unit of the amount of substance in the International System of Units (SI). It is defined as exactly 6.02214076×10^23 elementary entities which may be atoms, molecules, ions, or electrons.According to the question, the moles to the option is as follows:-
moles of 30 grams of CO2 is[tex]n =\frac{M}{M.M}\\ \\\frac{30}{44} \\\\=0.681\\\\[/tex]
The number of molecules is [tex]0.68 *6022*10^{23} =4.09496*10^{23[/tex].
2. moles of 22 grams of NaCl is
[tex]\frac{22}{44}\\ \\=0.5\\\\[/tex]
Molecules will be [tex]0.5*6.022*10^{23} = 3.011*10^{23}[/tex]
3. moles of 50-gram ammonia
[tex]\frac{50}{17} \\\\2.94\\[/tex]
The number of molecules is [tex]2.94*6.022*10^{23} = 1770*10^{23[/tex]
For more information about the moles, refer to the link:-
https://brainly.com/question/15209553
What is an empirical formula?
Answer:
a formula giving the proportions of the elements present in a compound but not the actual numbers or arrangement of atoms.
Hope this helped!!!
Answer:
Empirical formulas show the simplest whole-number ratio of atoms in a compound
Explanation:
Why is particle size the main parameter used in selecting a mechanical phase-separation device?
Answer:
This is because mechanical phase-separation device such as filtration, centrifugation etc operate according to the unique particle size feature in which they are designed to separates.
The process of centrifugation separates particles of size range between 0.1 μm to 5.0 μm efficiently.
The process of filtration however varies as there are different types of pore sizes which covers a wide range of particle sizes.
Use the following steps to balance the redox reaction using half-reactions. Zn(s) + Fe3+ Zn2+ + Fe(s) (unbalanced) a. Write balanced oxidation and reduction half-reactions. Indicate which is the oxidation reaction and which is the reduction reaction. (6 points) b. Balance the charge in the two half-reactions by multiplying the half-reactions by the correct multiplication factors. (4 points) c. Add the equations and simplify to get the balanced equation.
Answer:
Explanation:
a )
Zn = Zn²⁺ + 2e ( oxidation reaction )
Fe³⁺ + 3e = Fe( s ) ( reduction reaction )
b )
[ Zn = Zn²⁺ + 2e ] x 3
[ Fe³⁺ + 3e = Fe( s ) ] x 2
-------------------------------------------------------------------
3 Zn + 2 Fe³⁺ + 6e = 3 Zn²⁺ + 2 Fe ( s ) + 6e
3 Zn + 2 Fe³⁺ = 3 Zn²⁺ + 2 Fe ( s )
Ethane- (-89) Butane- (0) Methanol- (64.7) Hexane- (69) Pentadecane- (270) Heptadecane- (302) a) A mixture of pendtadecane and heptadecane can be separated by______ b) Which pair of compounds are easiest to separate (i) Ethane and Pentadecane (ii) Ethane and Heptadecane (iii) Butane and Hexane (iv) Butane and Heptadecane
Answer:
(ii) Ethane and Heptadecane
Explanation:
The separation of all the species listed in the answer options for the question depends on the molar mass of each specie.
Ethane is a low molecular mass gas. It exists in the gaseous state at room temperature. However, heptadecane appears as a liquid because it has a greater relative molecular mass.
It is very easily to distinguish between the gas, ethane and the liquid heptadecane which is a high molecular mass alkane, hence the answer.
A hot metal plate at 150°C has been placed in air at room temperature. Which event would most likely take place
over the next few minutes?
Molecules in both the metal and the surrounding air will start moving at lower speeds.
Molecules in both the metal and the surrounding air will start moving at higher speeds.
The air molecules that are surrounding the metal will slow down, and the molecules in the metal will speed up
The air molecules that are surrounding the metal will speed up, and the molecules in the metal will slow down
Answer:
d
Explanation:
When two ionic compounds are dissolved in water, a double replacement reaction can... Group of answer choices occur if two of the ions form an insoluble ionic compound, which precipitates out of solution occur if the ions react to form a gas, which bubbles out of the solution never occur since all ions are in water occur if the ions react to form a gas, which bubbles out of the solution ionic compounds only react with nonmetals
Answer:
occur if two of the ions form an insoluble ionic compound, which precipitates out of solution
Explanation:
When two ionic compounds are dissolved in water, a double replacement reaction takes place if two of the ions form an insoluble ionic compound, which precipitates out of solution. In double displacement reaction ions switch partners. And hence, produce an insoluble precipitate.
Is this example of a direct proportion or an inverse proportion?
A. Direct proportion
B. inverse proportion
Answer:
Inverse proportion occurs when one value increases and the other decreases. For example, more workers on a job would reduce the time to complete the task. They are inversely proportional.
Answer:
A
Explanation:
Chromium is dissolved in sulfuric acid according to the following equation: Cr + H2SO4 ⇒ Cr2 (SO4) 3 + H2
a) How many grams of Cr2 (SO4) 3 can be obtained by reacting 165 g of 85.67% H2SO4 of purity?
b) If 485.9 g of Cr2 (SO4) 3 are obtained, what is the yield of the reaction?
Answer:
[tex]\large \boxed{\text{a)188.4 g; b) 98.67 $\, \%$}}[/tex]
Explanation:
We will need a balanced chemical equation with masses and molar masses, so, let's gather all the information in one place.
Mᵣ: 98.08 392.18
2Cr + 3H₂SO₄ ⟶ Cr₂(SO₄)₃ + 3H₂
To solve the stoichiometry problem, you must
Use the molar mass of H₂SO₄ to convert the mass of H₂SO₄ to moles of H₂SO₄ Use the molar ratio to convert moles of H₂SO₄ to moles of Cr₂(SO₄)₃ Use the molar mass of Cr₂(SO₄)₃ to convert moles of Cr₂(SO₄)₃ to mass of Cr₂(SO₄)₃
a) Mass of Cr₂(SO₄)₃
(i) Mass of pure H₂SO₄
[tex]\text{Mass of pure} = \text{165 g impure} \times \dfrac{\text{85.67 g pure} }{\text{100 g impure}} = \text{141.36 g pure}[/tex]
(ii) Moles of H₂SO₄
[tex]\text{Moles of H$_{2}$SO}_{4} = \text{141.36 g H$_{2}$SO}_{4} \times \dfrac{\text{1 mol H$_{2}$SO}_{4}}{\text{98.08 g H$_{2}$SO}_{4}} = \text{1.441 mol H$_{2}$SO}_{4}[/tex]
(iii) Moles of Cr₂(SO₄)₃
The molar ratio is 1 mol Cr₂(SO₄)₃:3 mol H₂SO₄ [tex]\text{Moles of Cr$_{2}$(SO$_{4}$)}_{3} = \text{1.441 mol H$_{2}$SO}_{4} \times \dfrac{\text{1 mol Cr$_{2}$(SO$_{4}$)}_{3}}{\text{3 mol H$_{2}$SO}_{4}} = \text{0.4804 mol Cr$_{2}$(SO$_{4}$)}_{3}[/tex]
(iv) Mass of Cr₂(SO₄)₃ [tex]\text{Mass of Cr$_{2}$(SO$_{4}$)}_{3} = \text{0.4804 mol Cr$_{2}$(SO$_{4}$)}_{3} \times \dfrac{\text{392.18 g Cr$_{2}$(SO$_{4}$)}_{3}}{\text{1 mol Cr$_{2}$(SO$_{4}$)}_{3}} = \textbf{188.4 g Cr$_{2}$(SO$_{4}$)}_{3}\\\text{The mass of Cr$_{2}$(SO$_{4}$)$_{3}$ formed is $\large \boxed{\textbf{188.4 g}}$}[/tex]
b) Percentage yield
It is impossible to get a yield of 485.9 g. I will assume you meant 185.9 g.
[tex]\text{Percentage yield} = \dfrac{\text{Actual yield}}{\text{Theoretical yield}} \times 100 \, \% = \dfrac{\text{185.9 g}}{\text{188.4 g}} \times 100 \, \% = \mathbf{98.67 \, \%}\\\\\text{The percentage yield is $\large \boxed{\mathbf{98.67 \, \%}}$}[/tex]
Determinación de pH Expresa las siguientes concentraciones de [H+ ] en función del pH • [H+] = 0.001 M • [H+] = 0.002 M • [H+] = 2.45X10-4 M • [H+] = 5.2X10-9 M • [H+] = 0.04 M
Answer:
• pH = 3.0
• pH = 2.70
• pH = 3.61
• pH = 8.28
• pH = 1.40
Explanation:
El pH es una medida en química usada para determinar el grado de acidez o basicidad en una solución.
Se define como:
pH = -log₁₀ [H⁺]
El - logaritmo de la concentración molar de H⁺
Para las concentraciones de H⁺ dadas:
• [H+] = 0.001 M
pH = -log (0.001M) = 3
pH = 3.0
• [H+] = 0.002 M
pH = -log (0.002M)
pH = 2.70
• [H+] = 2.45X10-4 M
pH = -log (2.45X10-4 M )
pH = 3.61
• [H+] = 5.2X10-9 M
pH = -log (5.2X10-9 M)
pH = 8.28
• [H+] = 0.04 M
pH = -log (0.04M)
pH = 1.40
why is carbon iv oxide used in fire extinguishers
Answer:
Carbon dioxide extinguishes work by displacing oxygen, or taking away the oxygen element of the fire triangle. The carbon dioxide is also very cold as it comes out of the extinguisher, so it cools the fuel as well.
Please help, this assignment is to hard for me. :(
Answer:
603000 J
Explanation:
The following data were obtained from the question:
Energy required (Q) =...?
Mass (M) = 10000 g
Specific heat capacity (C) = 2.01 J/g°C
Overheating temperature (T2) = 121°C
Working temperature (T1) = 91°C
Change in temperature (ΔT) =.?
Change in temperature (ΔT) =T2 – T1
Change in temperature (ΔT) = 121 – 91
Change in temperature (ΔT) = 30°C
Finally, we shall determine the energe required to overheat the car as follow:
Q = MCΔT
Q = 10000 × 2.01 × 30
Q = 603000 J
Therefore, 603000 J of energy is required to overheat the car.
What mass of Fe(OH)3 is produced when 35 mL of 0.250 M Fe(NO3)3 solution is mixed with 55 mL of a 0.180 M
KOH solution? (this is a limiting reactant problem).
Answer:
0.35 g.
Explanation:
We'll begin by calculating the number of mole of Fe(NO3)3 in 35 mL of 0.250 M Fe(NO3)3 solution.
This is illustrated below:
Molarity of Fe(NO3)3 = 0.250 M
Volume = 35 mL = 35/1000 = 0.035 L
Mole of Fe(NO3)3 =?
Molarity = mole /Volume
0.250 = mole of Fe(NO3)3 / 0.035
Cross multiply
Mole of Fe(NO3)3 = 0.25 x 0.035
Mole of Fe(NO3)3 = 8.75×10¯³ mole
Next, we shall determine the number of mole of KOH in 55 mL of 0.180 M
KOH solution. This is illustrated below:
Molarity of KOH = 0.180 M
Volume = 55 mL = 55/1000 = 0.055 L
Mole of KOH =.?
Molarity = mole /Volume
0.180 = mole of KOH /0.055
Cross multiply
Mole of KOH = 0.180 x 0.055
Mole of KOH = 9.9×10¯³ mole.
Next, we shall write the balanced equation for the reaction. This is given below:
3KOH + Fe(NO3)3 —> Fe(OH)3 + 3KNO3
From the balanced equation above,
3 moles of KOH reacted with 1 mole of Fe(NO3)3 to produce 1 mole of Fe(OH)3.
Next, we shall determine the limiting reactant. This can be obtained as follow:
From the balanced equation above,
3 moles of KOH reacted with 1 mole of Fe(NO3)3.
Therefore, 9.9×10¯³ mole of KOH will react with = (9.9×10¯³ x 1)/3 = 3.3×10¯³ mole of Fe(NO3)3.
From the above illustration, we can see that only 3.3×10¯³ mole out of 8.75×10¯³ mole of Fe(NO3)3 given is needed to react completely with 9.9×10¯³ mole of KOH.
Therefore, KOH is the limiting reactant and Fe(NO3)3 is the excess reactant.
Next, we shall determine the number of mole of Fe(OH)3 produced from the reaction.
In this case, we shall use the limiting reactant because it will give the maximum yield of Fe(OH)3 as all of it is consumed in the reaction.
The limiting reactant is KOH and the mole of Fe(OH)3 produce can be obtained as follow:
From the balanced equation above,
3 moles of KOH reacted to produce 1 mole of Fe(OH)3.
Therefore, 9.9×10¯³ mole of KOH will react to produce = (9.9×10¯³ x 1)/3 = 3.3×10¯³ mole of Fe(OH)3.
Finally, we shall convert 3.3×10¯³ mole of Fe(OH)3 to grams. This can be obtained as follow:
Molar mass of Fe(OH)3 = 56 + 3(16 + 1) = 56 + 3(17) = 107 g/mol
Mole of Fe(OH)3 = 3.3×10¯³ mole
Mass of Fe(OH)3 =?
Mole = mass /Molar mass
3.3×10¯³ = Mass of Fe(OH)3 / 107
Cross multiply
Mass of Fe(OH)3 = 3.3×10¯³ x 107
Mass of Fe(OH)3 = 0.3531 ≈ 0.35 g.
Therefore, 0.35 g of Fe(OH)3 was produced from the reaction.
explain why ply(ethene) can become a pollutant?
Answer:
ipotseeeeeeeeeeeeeeee
0.10 moles of sodium sulfate is dissolved into 12 mL of solution. What is the molar concentration of the solution?
Your answer should have two significant figures (round your answer to one decimal place).
the molar concentration should be atleast 5mL off the solution since its disolved
Answer:
8.3
Explanation:
Convert mL to L.
12 mL×1 L1000 mL=0.012 L
Solve for molarity.
Molarity=moles of solute
liters of solution=0.10 mol0.012 L=8.3 M
why does a desert cooler better on a hot dry day
Answer:On a hot dry day humidity will be less.when humidity decreases rate of evaporation increases
Answer:
The water that evaporates from a desert cooler takes in energy from the environment for filling up for the loss of energy during EVAPORATION making the environment cold.
Therefore, on a hot dry day, the Evaporation is more which means the environment will be colder.
Explanation:
I hope it is okay.
I learnt it last year, so I went back to my book and explained it better in my own way.
Thanks.
Given that the density of air is 14.4, then the vapour of sulphur IV oxide is A. 16 B. 32 C. 64 D. 128
Thank you.
Answer:
32
Explanation:
The vapour density of a gas is the number of times a given volume of gas or vapour is as heavy as the same volume of hydrogen at a particular temperature and pressure.
Vapour density = 2 × relative molecular mass of the gas or vapour
Relative molecular mass of SO2 = 32 + 2(16) = 64
Hence;
Vapour density of SO2 = 64/2
Vapour density of SO2 = 32
What is 16.30 to the 100th gram
Answer:
1.65485688 × 10121 grams
Explanation:
Aside from those discrete items, anything like rice or flour can be measured out to make up 100 grams. For example, 1/2 cup (125 ml or about 4 and 1/2 fl. oz) of dry rice weighs very close to 100 grams.
Potatoes are cut into many parts, making sure that each part has at least one eye (bud). Each piece of potato will usually grow into a new potato plant. Will a new potato plant grow, if planted only with the eye? A. Yes, a full new potato plant can grow from it. B. Yes, but the new plant will take a slightly longer time to germinate. C. No, a new potato plant will not grow because the food needed for germination comes from the potato piece. D. No, a new potato plant will not grow because the leaves emerge only from the potato piece.
Answer:
b
Explanation:
the eye is the most important so it would grow but it will take some time because if we plant it with piece it has some food
3.0 cm x 4.0 cm x 1.0 cm
[?]cm^3
Explanation:
Hi there!!
you asked to multiply these all right,
you can simply multiply it ,
=3cm × 4 cm × 1cm
= 12cm^2×1cm (4×3=12)
= 12cm^3 (12×1=12)
Therefore, theanswer is 12 cm^3.
Hope it helps..
Difference between atomic number and atomic weight any 2 points
Answer:
According to the definitions given, atomic mass which is also called atomic weight is the measured total mass of an element's atom. Whereas, atomic number is nothing but the total number of neutrons and protons in the nucleus of an atom....
can u talk to in comment section
A student made the Lewis dot diagram of a compound as shown. Mg is written with two dots shown on its top. Cl is written on the right side of Mg. Cl has seven dots around it. An arrow is shown from one dot on Mg toward the vacant space around Cl. Another arrow is shown from the other dot on Mg toward the vacant space around Cl. On the top, the art title is written as Students Lewis Dot Model. What is the error in the Lewis dot diagram?
Answer:
The dots were not properly located and arrows are not used in Lewis structures
Explanation:
If we intend to write a Lewis structure for a compound, that lewis structure must consist of only dots. These dots actually show the valence electrons on the outermost shell of the molecule.
We do not involve arrows when writing dot electron structures for compounds. The valence electrons of magnesium ought not to be written together because they are not a lone pair, rather they are two unpaired electrons. The use of an arrow suggests a coordinate covalent bond which is not the case here.
The correct lewis structure for MgCl2 is shown in the image attached to this answer.
Answer: B is the answer took the test
Explanation: both electrons of Mg should be transferred to one O atom...
Choose all the answers that apply
Protons:
Have a positive change
Have no change
Are found in the nucleus
Orbit the nucleus
Have a negative charge
What group is calcium and sodium in?
Answer:
Calcium: Alkaline Earth
Sodium: Alkali Metal
Hope it helps!
Answer:
Calcium is in Alkaline Earth
Sodium is in Alkali Metal
Which of the following is NOT a product of the electrolysis of NaCl? A. Chlorine gas B. None of these C. Hydrogen gas D. Oxygen gas
Answer:D. Oxygen gas
Explanation: because the experiment showed
begging u to answer Which is not an inter molecular force? Select one: a. Inter atomic bonds b. van der waals forces c. hydrogen bonds
Answer:
a-Interatomic bonds
Explanation:
First of all, it is not a force. Let alone be molecular force.
Which of these scientist is know for his work in understanding climate change a : edwin hubble b : christian doppler c : warren washington d : charles kuen kao
Answer: just trust me its c
Explanation: i dont cap
plz answer fast i beg u
Which are not particles that enable electrical conductivity?
Select one:
a. delocalised electrons
b. molecules
c. mobile ions
Answer:
The correct option is;
a. Delocalised electrons
Explanation:
The particles that enable electrical conductivity are the delocalised electrons
The metallic structure consists of identically shaped elements having positive ions that have a resultant alignment, surrounded by a vast array of deloclised electrons, which move freely in the metallic structure such that a metallic part usually has a high electrical conductivity.
Therefore, the freely moving delocalised electron in a metal give them the property of good conductors of electricity.
brainliest to whoever gets it the soonest, what SI unit do you use to measure the length of a book, and what tool and unit for the volume of a box?
Answer:
The SI unit of volume is the cubic meter (m 3 ), which is the volume occupied by a cube that measures 1 m on each side. This very large volume is not very convenient for typical use in a chemistry laboratory. A liter (L) is the volume of a cube that measures 10 cm (1 dm) on each side.
A gas has a volume of 25.0 mL at 2.50 atm. What is the volume at 457 mmHg if the temperature remains constant?
Answer:
≈ 0.104 liters
Explanation:
We can use Boyle's Law: [tex]P_{1}V_{1} = P_{2}V_{2}[/tex]
P₁ = 2.50 atm
V₁ = 25.0 mL
P₂ = 457 mmHg
V₂ = ?
Because pressure should be in atm we will convert 457 mmHg to units in atm:
1 atm = 760mmHg so we can divide 457 by 760 and we get ≈ 0.601atm
Next we can plug in the units to the equation for Boyle's Law:
(2.50)(25.0) = (0.601)(V₂)
Solve for V₂
V₂ will give you ≈ 104mL or 0.104L
Either is correct depending on which unit they are asking you to use
