Answer:
se lonh hion ffyuk jlngvn
0.45g sample of mineral ore is analyzed for chromium and found contain 0.560mg Cr2 O3. Express concentration of Cr2O3 in sample as percent
Answer:
0.124% of Cr2O3 in the sample
Explanation:
A mass percent is expressed as 100 times the ratio of the mass of analyte and the mass of the sample. For this problem, the equation is:
Mass Cr2O3(g) / Mass Mineral(g) * 100
To solve this question we must convert the mass of Cr2O3 to grams and then, compute the value in the equation:
Mass Cr2O3 in g:
0.560mg * (1g / 1000mg) = 5.6x10⁻⁴g Cr2O3
Percent of Cr2O3 is:
5.6x10⁻⁴g Cr2O3 / 0.45g * 100
0.124% of Cr2O3 in the sampleCalculate the number of water (H2O) molecules produced from the decomposition of 75.50 grams of Iron (III) hydroxide (Fe(OH)3).
Answer: [tex]6.38\times 10^{23}[/tex] molecules of water are produced.
Explanation:
To calculate the moles :
[tex]\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}[/tex]
[tex]\text{Moles of} Fe(OH)_3=\frac{75.50g}{106.8g/mol}=0.707moles[/tex]
The balanced chemical reaction is:
[tex]2Fe(OH)_3\rightarrow Fe_2O_3+3H_2O[/tex]
According to stoichiometry :
2 moles of [tex]Fe_2O_3[/tex] produce = 3 moles of [tex]H_2O[/tex]
Thus 0.707 moles of [tex]Fe_2O_3[/tex] will produce=[tex]\frac{3}{2}\times 0.707=1.06moles[/tex] of [tex]H_2O[/tex]
According to avogadro's law, 1 mole of every substance contains avogadro's number [tex]6.023\times 10^{23}[/tex] of particles.
Thus 1.06 moles of [tex]H_2O[/tex] contains = [tex]\frac{6.023\times 10^{23}}{1}\times 1.06=6.38\times 10^{23}[/tex] molecules
Answer:
6.381 x 10^23
Explanation:
Explain whether each of the possible reactions listed below will occur. For those that will, predict what the products will be.
Zn(s) + H₂O (l) →
Sn(s) + O2(g) →
Cd(s) + Pb(NO3)2 (aq) →
Cu (s) + HCl(aq) →
Answer:
Zn(s) + 2H₂O (l) → Zn(OH)2(aq) + H2(g)
Sn(s) + O2(g) →SnO2(s)
Cd(s) + Pb(NO3)2 (aq) →Cd(NO3)2 (aq) + Pb(s)
Cu (s) + HCl(aq) → can not occur
Explanation:
Metals reacts with liquid water to yield the corresponding metallic hydroxide and hydrogen gas as shown above; Zn(s) + 2H₂O (l) → Zn(OH)2(aq) + H2(g)
Tin reacts with oxygen to yield tin (IV) oxide. This is an oxidation reaction as shown; Sn(s) + O2(g) →SnO2(s)
The reaction between Cd and Pb(NO3)2 is a single replacement reaction. It is possible because Cd is above Pb in the electrochemical series. Hence the reaction occurs thus; Cd(s) + Pb(NO3)2 (aq) →Cd(NO3)2 (aq) + Pb(s)
Copper does not displace hydrogen from dilute acids (such as HCl) since copper is lower than hydrogen in the electrochemical series hence the reaction does not occur.
True or False: Strong HYDROGEN bonds cause surface tension.
Choose
True or False: Many polar substances are soluble in water.
True or False: Cohesion and adhesion contribute positively to the capillary action property of water.
True or False: Water's molecular shape is trigonal planar.
True or False: Most water on earth is found in the liquid form.
True or False: Surface Tension makes it possible for some insects to walk
on water.
True or False: Capillary action is how tall trees get water from the leaves TO the roots.
True or False: Water has the density of 1.0 g/mL.
True or False: Water does not change temperature easily."
True or False: Water is highly polar.
True or False: Adding soap to water increases surface tension.
True or False: Evaporation and Vaporization are the same thing."
True or False: Nonpolar substances are NEVER soluble in water."
True or False: Water is an example of an strong IONIC bond..
True or False: The solid phase of water (ice) is more dense than the liquid
phase of water.
Which measurable property of potassium can be used to support this statement: "Matter can be subdivided to the atomic level while retaining its defining characteristics."
A. Temperature
B. Density
C. Mass
D. Volume
Which shape of eyeglass lens should be placed in front of the eye in order for the image to form on the retina?
A
concave
B
convex
C
flat
D
objective
Answer:
B
convex: for long sightedness
Or
A
concave: for short sightedness
The concave shape of the eyeglass lens should be placed in front of the eye in order for the image to form on the retina. Therefore, option A is correct.
What is retina ?The retina is a layer of photoreceptor cells and glial cells within the eye that captures incoming photons and transmits them as both electrical and chemical signals to the brain, allowing the brain to perceive a visual image.
The retina converts light that enters your eye into electrical signals that your optic nerve transmits to your brain, resulting in the images you see. It's an important part of your vision. The retina is the layer at the back of your eye.
Placing concave lenses in front of a nearsighted eye reduces light refraction and increases focal length, allowing the image to form on the retina.
A concave lens, which diverges light rays before they enter the eye, allows the myopic eye to focus the image of a distant object on the retina.
Thus, option A is correct.
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How many liters of O2 would be needed to produce 5.75 moles of K₂O?
Answer:
just 1
Explanation:
Is a shrimp an arachnid?
is a pill bug a insects, arachnid, or crustaceans?
is a scorpions a insects, arachnid, or crustaceans?
Answer:
Insects belong to the class Insecta, and arachnids to the class Arachnida; both classes fall under the Arthropoda phylum, along with crustaceans (crabs, lobster and shrimp). All arthropods have an exoskeleton and jointed legs. They have segmented bodies and appendages, which are divided into different segments. Arachnids belong to an even larger group of animals called “arthropods” which also include insects and crustaceans (lobster, crabs, shrimp, and barnacles).
Explanation:
An unknown mass of Al absorbs 187.9 J of heat and increases its temperature from 23.5 °C to 35.6 °C. What is the mass of the
aluminum?
Where:
Specific Heat of Aluminum is = 0.900 J/gºC
Answer:
mass = 17.2 grams
Explanation:
q = mcΔT => m = q/cΔT = 187j / (0.90j/g°C)(35.6°C - 23.5°C) = 17.2g
PLEASE HELP ASAP In the past, California has had many droughts. Which part of the water cycle is not active when a drought is occurring?
precipitation
condensation
transpiration
evaporation
?
Answer :D: evaporation
Explanation: cus i am smart
sorry if i am wrong heh
5-O selênio e o enxofre pertencem à família VI A da tabela periódica. Sendo assim, o seleneto e o
sulfeto de hidrogênio são representados, respectivamente pelas fórmulas:
a) HSe e HS
b) H 2 Se e HS
c) HSe e H 2 S
d) H 2 Se e H 2 S
e) H 3 Se e H 3 S
Answer:
Opção D está correta
Explanation:
Conforme indicado no parágrafo -
o selênio e o enxofre pertencem à família VI A da tabela periódica
Seleneto de hidrogênio - H2Se
Sulfato de hidrogênio - H2S
Portanto, a opção D está correta
In the context of this graph, what do the slope and y-intercept mean?
Answer: The slope and y-intercept values indicate characteristics of the relationship between the two variables x and y. The slope indicates the rate of change in y per unit change in x. The y-intercept indicates the y-value when the x-value is 0.
1.
What is the molarity of a 3.6 L solution with 104 g of sucrose?
Answer:
.084 M
Explanation:
Molar mass of sucrose = 342.3
The formula to find molarity is moles of solute / liters of solution
Since we need to turn grams to moles for this equation we do 104 / 342.3 = 0.304
Now we can use the equation listed above. .304 / 3.6 = 0.084 M
why does hexane have the weakest intermolecular force?
Answer:
The only intermolecular forces present in the compound Hexane are London dispersion forces which are generally the weakest. Hexane's molecular structure proves that Dipole-Dipole forces wont exist as there aren't very polar bonds in the structure.
PLEASE HELP ASAP NO LINKS PLEASE
What is the force that keeps the planets in perfect orbit around the sun?
A) Velocity
B) Gravity
C) Centrifugal Force
D) Magnetism
Answer:
gravity
Explanation:
Gravity is the force that pulls us to the surface of the Earth, keeps the planets in orbit around the Sun and causes the formation of planets, stars and galaxies.
Hope this helped!!!
Which of the following is a correct statement?
1 :Vacuum is an opaque body
2 :Reflection takes place from the polished smooth surfaces
3 :Moon is a luminous body in the sky
4 :A pin hole camera can take pictures on moving objects
5 :Shadows are always inverted
Answer:
Reflection takes place from the polished smooth surfaces
Explanation:
A vacuum does not refer to an opaque body. An opaque body does not allow light to pass through it while a vacuum is simply empty space without air.
A smooth polished surface often acts as a mirror, it is a good reflector of light.
The moon is a non luminous body in the sky. It merely reflects the light from the sun.
A Pinhole camera can not take pictures of moving objects because it only focuses on any image placed before it.
Shadows are not inverted, the always appear upright.
HELP!
NaCl is made from 1 Na and 1 Cl. If I have 45.978 grams of Na, how many grams of NaCl can I make? (You will have to convert to moles of Na first!)
explain answer
Answer:
116.88 g
Explanation:
Step 1: Write the balanced equation for the synthesis of NaCl
Na + 1/2 Cl₂ ⇒ NaCl
Step 2: Calculate the moles corresponding to 45.978 g of Na
The molar mass of Na is 22.990 g/mol.
45.978 g × 1 mol/22.990 g = 1.9999 mol
Step 3: Calculate the number of moles of NaCl formed from 1.9999 moles of Na
The molar ratio of Na to NaCl is 1:1. The moles of NaCl formed are 1/1 × 1.9999 mol = 1.9999 mol.
Step 4: Calculate the mass corresponding to 1.9999 moles of NaCl
The molar mass of NaCl is 58.443 g/mol.
1.9999 mol × 58.443 g/mol = 116.88 g
How is the motion of particles in a book different from the motion of particles in the air around it ? (dont put link)
Answer:
the motion is different.
Explanation:
the the motion is different because the particle in a book is solid particles and solid are packed together so so they can't move freely but while the the particles in the air around it is gas particles and it are packed very loose and can move very easily anywhere like .Example - solid-book , eraser. gas-helium, oxygen.
Which applies to fusion? Check all that apply.
involves the splitting of nuclei
takes place in the Sun
releases radiation as a waste product
occurs in nuclear power plants and is used to generate electricity
plays a role in the production of essentially all elements heavier than helium
releases large amounts of energy
Answer: B, E, and F
Explanation: It showed the correct answer after i got it incorrect. (E2021)
Answer:
A
B
D
E
Explanation:
GOT IT RIGHT ON MY ASSIGNMENT
Pb(NO3)2(aq)+2KCI(aq)------- PbCl2(s)+2KNO2 (aq). how many grams of PbCl2 solution will react with a 0.46L of a 0.101m KCI solution
Answer:
6.46g of PbCl2 are produced
Explanation:
The PbCl2 will not react, is a product of the reaction. The question must be say how many grams of PbCl2 will be produced
Based on the chemical reaction:
Pb(NO3)2(aq)+2KCI(aq) → PbCl2(s)+2KNO2 (aq)
1 mole of PbCl2 is produced when 2 moles of KCl are reacting.
To solve this question we must find the moles of KCl that will react. With these moles we can find the moles of PbCl2 and the grams produced using its molar mass:
Moles KCl:
0.46L * (0.101moles / L) = 0.04646 moles KCl
Moles PbCl2:
0.04646 moles KCl * (1mol PbCl2 / 2mol KCl) =
0.02323 moles of PbCl2 are produced
Mass -Molar mass PbCl2: 278.106g/mol-
0.02323 moles * (278.106g / mol) =
6.46g of PbCl2 are producedhi so can help me with something
What does Aluminum and Magnesium oxide create
Answer: MgAl2O4 or Spinel (gemstone)
Explanation:
What is the maximum amount in moles of P2O5 that can theoretically be made from 240 g of O2 and excess phosphorus?
Answer:
hope it will help you out :)
In a nuclear power plant, what is the purpose of the cooling tower?
cools down the electric generator
reduces heat pollution to the environment
pumps cool water into the reactor
Answer:
reduces heat pollution to the environment
1. Identify the reactants in this chemical equation:
2H2 + O2 + 2H2O
Help fast !
If I have an unknown quantity of gas at a pressure of 102 kPa, a volume of 31 liters, and a temperature of 87 0C, how many moles of gas do I have?
Answer:
1 mole represents 6.023×1023 particles.
1 mole of iodine atom= 6.023×1023
Given 127.0g of iodine.
no. of iodine atom = 1 mole of iodine
1mole of magnesium = 24g of Mg = 6.023×1023no.of Mg
Given 48g of Mg = 2×6.023×1023
no. of Mg = 2 moles of Mg
1 mole of chlorine atom= 6.023× 1023
no. of chlorine atom = 35.5g of chlorine atom
Given 71g of chlorine atom=2× 6.023× 1023
no. of chlorine atom = 6.023×1023
2 moles of chlorine atom.
Given that 4g of hydrogen atom.
will be equal to 4 × 6.023 × 1023
no. of atoms of hydrogen= 4 moles of hydrogen atom.
Read the excerpt from A History of Women’s Suffrage by Stanton, Anthony, and Gage.
Another writer asserts that the tyranny of man over woman has its roots, after all, in his nobler feelings; his love, his chivalry, and his desire to protect woman in the barbarous periods of pillage, lust, and war. But wherever the roots may be traced, the results at this hour are equally disastrous to woman. Her best interests and happiness do not seem to have been consulted in the arrangements made for her protection. She has been bought and sold, caressed and crucified at the will and pleasure of her master. But if a chivalrous desire to protect woman has always been the mainspring of man's dominion over her, it should have prompted him to place in her hands the same weapons of defense he has found to be most effective against wrong and oppression.
Which statement paraphrases the authors’ argument?
Throughout history, men have strived to protect women through chivalrous action and guardianship.
Women have always been subservient to men because they have needed protection during war and pillage.
Men have not been successful protecting women because they have not given women the power to protect themselves.
During times of war, men and women rely on one another for defense, and they each have weapons for battle.
Answer:
C
Explanation:
Took the test
In her book A Vindication of the Rights of Women, British author Mary Wollstonecraft advocated that women should be treated with the same respect and decency as men, particularly when it comes to education. Thus, option C is correct.
What Women’s Suffrage by Stanton, Anthony, and Gage?A Vindication of the Rights of Woman (1792), a groundbreaking feminist text, asserts that girls should be given the same privileges as males.
So that they might become outstanding husbands, mothers, and laborers in addition to being educated to be frivolous and inept by the educational system.
Women should be given the same opportunities as men, and women share the same capacity for reasoning at birth. Women should have the same rights to influence, expertise, and power in society as men do.
Therefore, Men have failed in their attempts to safeguard women because they have not given them the means to do so.
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What are the 3 main types of clouds?
Answer:
Cumulus, Cirrus, and Stratus
Explanation:
So Cumulus Clouds are those puffy-shaped clouds, the ones that look the most solid like you could just walk on them. Cirrus are those wispy clouds that are often very high up. And Stratus Clouds are the low clouds that often cover the entire sky.
hope this helps:)
A woman needs a kidney transplant. The best candidate to donate a kidney to her is her
es -0)
A)
Co-Worker.
B)
daughter.
09
friend.
D
husband.
Answer: B
Explanation:
2C4H10+13O2-->8CO2+10H2O Using the predicted and balanced equation, How many Liters of CO2 can be produced from 150 grams of C4H10?
Answer: 233 L of [tex]CO_2[/tex] will be produced from 150 grams of [tex]C_4H_{10}[/tex]
Explanation:
To calculate the moles :
[tex]\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}[/tex] [tex]\text{Moles of} C_4H_{10}=\frac{150g}{58g/mol}=2.59moles[/tex]
The balanced chemical equation is:
[tex]2C_4H_{10}+13O_2(g)\rightarrow 8CO_2+10H_2O[/tex]
According to stoichiometry :
2 moles of [tex]C_4H_{10}[/tex] produce = 8 moles of [tex]CO_2[/tex]
Thus 2.59 moles of [tex]C_4H_{10}[/tex] will produce=[tex]\frac{8}{2}\times 2.59=10.4moles[/tex] of [tex]CO_2[/tex]
Volume of [tex]CO_2=moles\times {\text {Molar volume}}=10.4moles\times 22.4mol/L=233L[/tex]
Thus 233 L of [tex]CO_2[/tex] will be produced from 150 grams of [tex]C_4H_{10}[/tex]
What is required to make a fire? Is it exothermic or endothermic?
Answer:
Combustion as an Exothermic Reaction
Explanation:
When substances burn, they usually give off energy as heat and light. The combustion of wood is an exothermic reaction that releases a lot of energy as heat and light.
Answer:
Exothermic
Explanation:
because exothermic causes fires while endothermic doesn't