Answer:
Option (2), (3) and (5).
Explanation:
Chemical change: It is a chemical reaction in which arrangement of atoms of one or more than one substance changes to give new substances as a product.Chemical change can be in form of : color change, formation of precipitate, formation of bubbles.
In option (2), bubbles were produced when iron was placed in acid which means gas was released on adding iron to acid.Yes, it is a chemical change.
In option (3), solid that is precipitate is obtained as a product from the reaction between two liquids which means that change in arrangement of atom had taken place.Hence, a chemical change.
In option (5), white substance turned blue when water was added. Color of white solid changes to blue which means that chemical change has taken place.
So, option are (2), (3) and (5) are examples of chemical changes.
How many atoms are in each elemental sample? 7.64 g Bi
How many atoms are in each elemental sample? 35.8 g P
Answer:
• 7.64 g Bi = 2.20 x 10²² atoms
• 35.8 g P = 6.95 x 10²³ atoms
Explanation:
First calculate the number of moles in each sample:
no. of moles = mass ÷ molar mass (RMM)
• 7.64 g Bi = 7.64 ÷ 209
= 0.03656 mol
• 35.8 g P = 35.8 ÷ 31
= 1.155 mol
Then multiply the number of moles by Avogadro's constant (6.02x10²³):
• 0.03656 x 6.02x10²³ = 2.20 x 10²² atoms
• 1.155 x 6.02x10²³ = 6.95 x 10²³ atoms
The density of lead is 11.4 g/cm3. Convert the density to lb/ft3. 1 lb = 454.55 g 1 ft = 12 in 1 in = 2.54 cm
When we convert 11.4 g/cm³ to lb/ft³, the result obtained is 707.92 lb/ft³
How to convert 11.4 g/cm³ to lb/cm³454.55 g/cm³ = lb/cm³
Therefore,
11.4 g/cm³ = 11.4 / 454.55
11.4 g/cm³ = 0.025 lb/cm³
How to convert 0.025 lb/cm³ to lb/ft³cm1 ft = 12 in
1 in = 2.54 cm
Thus,
12 in = 12 × 2.54
12 in = 30.48 cm
We can say
1 ft = 30.48 cm
Therefore,
1 ft³ = 30.48³ = 28316.84 cm³
Now, we can convert 0.025 lb/cm³ to lb/ft³ as follow:
(1/28316.85) lb/cm³ = 1 lb/ft³
0.025 lb/cm³ = 0.025 ÷ (1/28316.85) = 0.025 × 28316.85
0.025 lb/cm³ = 707.92 lb/ft³
Thus,
11.4 g/cm³ = 707.92 lb/ft³
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What part of Dalton's atomic theory was later proved to be incorrect?
OA. All atoms are made up of elements that can combine in reactions.
OB. All atoms of one kind are called elements.
OC. All matter is made up of different kinds of elements.
O D. All atomsone kind are identical and cannot be divided.
Answer: All atoms of one kind are identical and cannot be divided.
Explanation:
This is a fact.
In which region is the substance in both the solid phase and the liquid phase? PLS HURRY
Answer:
2
Explanation:
At the constant temp, the substance is going from a solid to a liquid and both are present (like melting ice)
HELP ASAP!!!!!! I NEED HELP
1. Label each of the following organs on the picture below: pancreas, liver, stomach, small intestine,
large intestine.
2. In the space provided, describe the function of each organ you labeled.
The organs of the digestive system such as the pancreas, liver, stomach, small intestine, and large intestine help in the digestion of food.
What are organs?Organs are a collection of tissues that are closely related and which perform a related function.
The role and function of the organs of the digestive system are as follows:
Pancreas - produces pancreatic juice which contain digestive enzymesLiver - produces bile for the emulsification of fatStomach - serves as a temporary store of food and produces digestive juicesSmall intestine - functions in food digestionLarge Intestine - helps to remove undigested food from the bodyTherefore, the organs of the digestive system such as the pancreas, liver, stomach, small intestine, and large intestine help in the digestion of food.
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why does water evaperate
Explanation:
water evaporates because when h2o (water) particles heat up, they gain energy causing them to start to vibrate. this moves the oarticles further and further away from eachother and making the substance less dense, and turning it into a gas. meaning it has evaporated
Answer:
the sunlight heats the water up and makes the molecules move faster and faster until it becomes gas.
In the laboratory you dissolve 12.2 g of iron(II) iodide in a volumetric flask and add water to a total volume of 500 mL.
What is the molarity of the solution?
M.
What is the concentration of the iron(II) cation?
M.
What is the concentration of the iodide anion?
M.
Answer:
a.) 0.0788 M
b.) 0.0788 M
c.) 0.156 M
Explanation:
To find the molarity of the solution, you need to (1) convert grams FeI₂ to moles FeI₂ (via the molar mass from periodic table) and then (2) calculate the molarity (via the molarity equation using the moles and volume). To find the concentration of each ion, you need to multiply the compound's molarity by the amount of each ion in the molecule.
(Step 1)
Molar Mass (FeI₂): 55.845 g/mol + 2(126.90 g/mol)
Molar Mass (FeI₂): 309.645 g/mol
12.2 g FeI₂ 1 mole
------------------ x --------------------- = 0.0394 mole FeI₂
309.645 g
(Step 2)
500 mL / 1,000 = 0.5 L
Molarity (M) = moles / volume (L)
Molarity = 0.0394 mole / 0.5 L
Molarity = 0.0788 M
(Step 3)
FeI₂ = 1 iron cation and 2 iodide anions
Iron (II) Cation: 1 x 0.0788 M = 0.0788 M
Iodide Anion: 2 x 0.0788 M = 0.156 M
what effect do you think global warming might have on the availability of fresh water
Global Warming results in rising sea levels as the freshwater from the melted glaciers eventually runs into the ocean.
What is Global Warming ?
A gradual increase in the overall temperature of the earth's atmosphere generally attributed to the greenhouse effect caused by increased levels of carbon dioxide, CFCs, and other pollutants.
As the climate warms, harmful algal blooms happen more often and become more severe.
As the ocean warms, freshwater glaciers around Earth begin to melt at an unsustainable rate, which results in rising sea levels.
The freshwater from the melted glaciers eventually runs into the ocean.
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Which of the following conversion factors would be used to calculate the number of moles of Cl2 produced if 11 moles of HCl were present in the following reaction:
4HCl + O2 --> 2Cl2 + 2H2O
Group of answer choices
4 mol HCl
2 mol Cl2
1 mol HCl
4 mol Cl2
2 mol H2O
2 mol Cl2
1 mol O2
2 mol H2O
The conversion factor that would be used to calculate the number of moles of Cl2 produced if 11 moles of HCl were present in the reaction is as follows:
4 mol HCl; 2 mol Cl2
How to calculate number of moles stoichiometrically?The number of moles of a reactant or product of a reaction can be calculated using stoichiometry.
According to this question, the following balanced chemical reaction was given:
4HCl + O2 --> 2Cl2 + 2H2O
This reaction shows that 4 moles of HCl is required to produce 2 moles of Cl2, therefore, this is the conversion factor that would be used to calculate the number of moles of Cl2 if 11 moles of HCl was present.
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If a class that was 25% boy dogs had 40 dog boys in the class, how many dog girls were in this class?
What’s the anwser ????????????????????
The oxidation state of N changes from +2 to 0 while that of C changed from +2 to +4.
Oxidation and reductionOxidation is defined as an increase in oxidation number of the addition of oxygen while reduction is a decrease in oxidation number or removal of oxygen.
In the reaction shown by the equation, the oxidation number of N in NO changed from +2 to 0 in [tex]N_2[/tex] while that of C in CO changed from +2 to +4 in [tex]CO_2[/tex].
Thus, NO is acting as the oxidizing agent while CO is acting is the reducing agent.
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The oxidation state of nitrogen in NO changes from +2 to 0, and the oxidation state of carbon in CO changes from +2 to +4 as the reaction proceeds.
What is reduction?Reduction simply refers to a half-reaction through which the number of electrons (oxidation states) that are associated with the atoms of a given chemical element are changed, especially by being reduced or decreased.
Based on this chemical reaction which occurs in a car’s catalytic converter, we can logically deduce that the oxidation state of nitrogen (N) in NO changes (decreases) from +2 to 0, and the oxidation state of carbon (C) in CO changes (decreases) from +2 to +4 as the reaction proceeds:
2NO(g) + 2CO(g) ==> N₂(g) + 2CO₂(g)
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deduce the possible sets of four quantum number when n=2
Answer:
+ 1/2 and -1/2
Explanation:
if n=2 then l=n-1 i.e, l=1 and 0.
m=plus minus l
so, m= -1, 0, +1
nd spin quantum no. will be + 1/2 and -1/2
Answer:
+ 1/2 and -1/2
Explanation:n=2 then l=n-1 i.e, l=1 and 0.m=plus minus lso, m= -1, 0, +1
When 0.0075mol of alcohol x are completely burnt in excess oxygen and the gases produced are passed through an excess of limewater (calcium hydroxide solution), 3.0g of calcium carbonate are produced. When X is warmed with acidified potassium dichromate (VI) there is a color change from orange to green. What could be the identity of X?
X could be [tex]CH_3CH(OH)CH_2CH_3[/tex] when X is warmed with acidified potassium dichromate (VI) there is a colour change from orange to green.
What is alcohol?Alcohol is formed when yeast ferments (breaks down without oxygen) the sugars in different food.
Aldehydes reduce dichromate from the +6 to the +3 oxidation state, changing colour from orange to green. This colour change arises because the aldehyde can be oxidized to carboxylic acid.
Hence, X could be [tex]CH_3CH(OH)CH_2CH_3[/tex] when X is warmed with acidified potassium dichromate (VI) there is a colour change from orange to green.
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determine and compare the physical properties of potassium chloride and zinc and wax. please
Answer:
odorless, crystalline, white solid with a sour taste.
Explanation:
Your cotton T-shirt smells when you take it out of the clothes dryer. Explain why.
Answer:
When the T-shirt comes out of the clothes dryer, it is so warm that molecules from the detergent and fabric soft ener are likely to have changed phase and become gases. When they reach your nose, you are able to smell them.
Explanation:
A chamber has a pressure of 1.5 atm at a volume of 1.4 L. What is the pressure when the piston compresses the sample
to a volume of 0.60 L?
Select one:
a. 1.8 L
b. 0.64 L
c. 3.5 L
d. 1.6 L
e. 0.29 L
Answer:
C.) 3.5 atm
Explanation:
Because you are dealing with pressure and volume, you can use Boyle's Law to help you find the missing variable. The general formula looks like this:
P₁V₁ = P₂V₂
In this formula, "P₁" and "V₁" represent the pressure and volume of the chamber originally. "P₂" and "V₂" represent the final pressure and volume. You have been given the values of all the other variables but "P₂". Therefore, you can plug these values into the formula and simplify to find the final pressure.
P₁ = 1.5 atm
V₁ = 1.4 L
P₂ = ?
V₂ = 0.60 L
P₁V₁ = P₂V₂ <---- Boyle's Law formula
(1.5 atm)(1.4 L) = P₂(0.60 L) <---- Plug in values
2.1 = P₂(0.60 L) <---- Multiply 1.5 and 1.4
3.5 = P₂ <----- Divide both sides by 0.60
Why is the name of Si3N4 silicon nitride even though it has covalent bonds?
Pure silicon nitride is difficult to produce as a fully dense material. This covalently bonded material does not readily sinter and cannot be heated over 1850°C as it dissociates into silicon and nitrogen.
[tex]\textrm {Silicon nitride}[/tex] [tex]\mathrm {(Si_{3}N_{4})}[/tex] [tex]\textrm {is a chemical compound containing silicon and nitrogen.}[/tex]
[tex]\textrm {Due it to its high thermodynamic stability, it is relatively chemically}\\\textrm {inert and very hard in nature.}[/tex]
[tex]\textrm {Until 1960, it was widely believed covalent compounds could not be}\\\textrm {sintered, a process of converting a powdered material into a solid mass.}[/tex]
[tex]\textrm {Since the title of the compound was already given at the time,} \\\textrm {it was not changed later on.}[/tex]
please help asap!!!!!!!
Answer:
A.
Explanation:
Power is measured in Watts, and can we calculated by taking the work done in joules / the time in seconds. Thus, 1 Watt is 1 joule per 1 second (1 Watt = 1J/s)
Answer:
A
Explanation:
Which statement is true about the law of reflection?
Group of answer choices
The angle of reflected light is larger than the incoming angle of light.
The angle of reflected light distorts the image to appear larger or smaller.
The angle of reflected light is smaller than the incoming angle of light.
The angle of reflected light is the same as the incoming angle of light.
plssssssssssssssssssss HELP
Answer:
The law of reflection defines that upon reflection from a smooth surface, the angle of the reflected ray is equal to the angle of the incident ray, with respect to the normal to the surface that is to a line perpendicular to the surface at the point of contact.
The reflected ray is always in the plane defined by the incident ray and the normal to the surface at the point of contact of the incident ray.
The images produced by plane mirrors and curved mirrors can be understood by the law of reflection.
Law of reflection is defined as:
The principle when the light rays falls on the smooth surface, the angle of reflection is equal to the angle of incidence, also the incident ray, the reflected ray, and the normal to the surface all lie in the same plane.
What is Reflection of Light?
The process through which light rays fall on the surface and gets bounced back is known as a reflection of light.
how much of the original amount of an isotope is present after a period of four half lives
After 2 half-lives there will be 25% (1/4th) of the original isotope, and 75% (3/4 th) of the decay product
What is Half life period ?A half life is a measurement of the slope of an exponential decay function.
It is also defined as, the time it takes to halve the concentration of something in a process.
Each half life you will have half of what you had at the beginning of a given half life.
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An invasive species is a species that disrupts the ecosystem into which it is introduced by displacing species.
Invasive species can do all sorts of damage to an existing ecosystem, including changing habitats and starving native animals of food and resources.
What is an invasive species?An invasive species is an organism that causes ecological or economic harm in a new environment where it is not native.
Invasive species can change the food web in an ecosystem by destroying or replacing native food sources. The invasive species may provide little to no food value for wildlife. Invasive species can also alter the abundance or diversity of species that are important habitats for native wildlife.
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Answer:
First drop down is non-native, the second drop down is native
Explanation:
Got it right on the test. An invasive species is not from the area, therefore it is non-native.
Another type of stress is a change in ______________.
A) temperature B) liquid C) solid D) catalyst
Answer:
a) temperature
Explanation:
Also known as thermal stress. In mechanics and thermodynamics, thermal stress is mechanical stress created by any change in temperature of a material.
Hope this helps!
What do the conclusions tell about the experiment?
O A. The conclusions tell if the scientific method was followed.
B. The conclusions tell how the experiment should be repeated.
OC. The conclusions tell why the data support or reject the
hypothesis.
OD. The conclusions tell what other scientists think about the
experiment.
Answer:
The conclusion tells why the data should be rejected or supported
Explanation:
When asked to identify conclusions based on investigation descriptions, data tables, graphs and drawings, remember to do the following:
Look back at the hypothesis.
Identify the independent and dependent variables.
Look at the data carefully.
Look for an overall trend in the data.
Determine if the data support or don't support the hypothesis
The common military explosive PETN (C5H8N4O12) belongs to the same chemical family as nitroglycerin, a
compound with medicinal uses as a vasodilator. Aside from sanctioned use, the “shoe bomber” attempted to
detonate a PETN device on a commercial airline flight to Miami in 2001.
Predict the number of moles of water formed from the combustion of 1 mole PETN.
For 1 mole of C₅H₈N₄O₁₂ , 4 moles of water will be produced.
What is a Combustion Reaction ?A combustion reaction is a chemical reaction in which a fuel/explosive undergoes oxidation , which results in release of high amount of energy.
The reaction of combustion of C₅H₈N₄O₁₂ (PETN) Explosive is
C₅H₈N₄O₁₂ → 4H₂O + 3CO₂ + 2CO + 2N₂
For 1 mole of C₅H₈N₄O₁₂ , 4 moles of water will be produced.
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The Chemistry Cafe was out of bread. The cook went next door to the bakery and bought a loaf of bread which has 33 slices. Then, she sells 12 sandwiches (two pieces of bread per sandwich). How much bread did she have left? Explain your answer.
Answer:
9
Explanation:
12 sandwiches uses 24 pieces and 33-24
When an object floats in water, it displaces a volume of water that has a weight equal to the weight of the object. If a ship has a weight of 4247 tons, how many cubic feet of seawater will it displace? Seawater has a density of 1.025 g·cm-3; 1 ton = 2000 lb. (Enter your answer in scientific notation.)
The amount of seawater that will be displaced would be 1.3274 x [tex]10^5[/tex] [tex]ft^3[/tex]
Density and volumeDensity = mass/volume.
Since a floating object displaces its own weight, a 4247 tons ship will also displace the same amount of water.
4247 tons of seawater = 3.8528 x [tex]10^9[/tex] g
volume of 3.8528 x [tex]10^9[/tex] g seawater = mass/density = 3.8528 x [tex]10^9[/tex] g/1.025 = 3758829268.29 cubic centimeter.
3758829268.29 [tex]cm^3[/tex] = 132741.80 [tex]ft^3[/tex] or 1.3274 x [tex]10^5[/tex] [tex]ft^3[/tex]
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The effect of chlorofluorocarbons on the depletion of the ozone layer is well known. The use of substitutes, such as CH3CH2F(g), fluoroethane, has largely corrected the problem. Calculate the volume occupied by 0.208 mol of CH3CH2F(g) at a temperature of 298.15 K and a pressure of 1 atm.
4.87 L
8.40 L
6.46 L
5.01 L
Answer:
6.46
Explanation:
Had this one
Option D
What is the name of Si3N4
A) silicon nitride
B) trisilicon tetranitride
What is the name of Si3N4
A) silicon nitride .
Answer:
[tex]\textrm {A) silicon nitride}[/tex]
Explanation:
[tex]\textrm {The title of the compound}[/tex] [tex]\mathrm {Si_{3}N_{4} }[/tex] [tex]\textrm {is silcon nitride.}[/tex]
[tex]\textrm {It cannot be called trisilicon tetranitride because a nitride group}\\\textrm {has 3 nitrogen atoms, and tetranitride would mean it has 4 times}\\\textrm {the number of atoms.}[/tex]
[tex]\textrm {Furthermore, tri- and tetra- are prefixes used for substituent}\\\textrm {groups present in compounds. Here, since only both of them}\\\textrm {are present, it cannot be called so.}[/tex]
How many moles of propylene (C3H6) are in 25.0
g
of the substance?
0.59 moles of propylene ([tex]C_3H_6[/tex]) are in 25.0g of the substance.
What are moles?A mole is defined as 6.02214076 × [tex]10^{23}[/tex] of some chemical unit, be it atoms, molecules, ions, or others. The mole is a convenient unit to use because of the great number of atoms, molecules, or others in any substance.
Given data:
Mass of propylene = 25.0g
Molar mass of propylene=42.08 g/mol
[tex]Moles = \frac{mass}{molar \;mass}[/tex]
[tex]Moles = \frac{25.0g}{42.08 g/mol}[/tex]
Moles =0.59 moles
Hence, 0.59 moles of propylene ([tex]C_3H_6[/tex]) are in 25.0g of the substance.
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IUPAC NAME FOR
[Fe(H2O)6](NO3)3
Explanation:
hexaaqua iron (III) trinitrate
