Answer:
d
Explanation:
According to law of conservation of mass, mass is conserved during burning of paper although the mass of ash is less than paper as some of the products are given out as gas.
What is law of conservation of mass?According to law of conservation of mass, it is evident that mass is neither created nor destroyed rather it is restored at the end of a chemical reaction .
Law of conservation of mass and energy are related as mass and energy are directly proportional which is indicated by the equation E=mc².Concept of conservation of mass is widely used in field of chemistry, fluid dynamics.
Law needs to be modified in accordance with laws of quantum mechanics under the principle of mass and energy equivalence.This law was proposed by Antoine Lavoisier in the year 1789.
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Which best illustrates the way in which radiation transfers thermal energy?
A red ball at left labeled warm does not touch a blue ball labeled cool at right. Curved arrows point from the blue ball to the red ball.
A red ball at left labeled warm does not touch a blue ball labeled cool at right. Curved arrows point from the red ball to the blue ball.
A red ball at left labeled warm touches a blue ball labeled cool at right. Straight arrows point from the blue ball to the red ball.
A red ball at left labeled warm touches a blue ball labeled cool at right. Straight arrows point from the red ball to the blue ball.
Answer:
B or the second answer.
Explanation:
It's heat transfer and the objects aren't directly touching. B is the only answer that fits.
Hope this helps!
Answer:
b
Explanation:
Which sphere forms Earth's outermost layer?
Atmosphere
Biosphere
Cryosphere
Hydrosphere
Answer: I believe the answer is A.
Explanation: Well, the lithosphere is rocks and earth, the hydrosphere makes up all the water on Earth, the biosphere is us, (living things,) and the atmosphere is the air that surrounds us and our planet. So if you go in order, it's basically lithosphere, hydrosphere, biosphere, and then atmosphere.
Answer:
Atmosphere
Explanation:
I took test
How many moles of oxygen would
be consumed to produce 68.1 g
water?
Answer:
4.75 moles of oxygen would be consumed by water
Explanation:
Given data:
Mass of water produced = 68.1 g
Number of moles of oxygen consumed = ?
Solution:
Chemical equation:
C₃H₈ + 5O₂ → 3CO₂ + 4H₂O
Number of moles of water:
Number of moles = mass/molar mass
Number of moles = 68.1 g/ 18 g/mol
Number of moles = 3.8 mol
Now we will compare the moles of water with oxygen.
H₂O : O₂
4 : 5
3.8 : 5/4×3.8 = 4.75 mol
Answer: 4.75 moles of oxygen
Explanation:
The skeletal structure in line‑angle (line‑bond) mode of 2‑isopropyltoluene is shown. Identify the number of hydrogen atoms bound to each carbon atom in the structure.
Answer:
Fourteen hydrogen atoms are bounded in total to the carbon atoms in the structure
Explanation:
The boxes that show "one" indicate that there is only one hydrogen atom bonded to that particular carbon atom while those that show "zero" shows there are no hydrogen atoms bonded to that particular carbon atom. Those that show "three" indicate that there are three hydrogen atoms bonded to that particular carbon.
There are 10 carbon atoms in the structure.
NOTE that each of these carbon atoms must be surrounded with four bonds; which was how the number of hydrogen atoms (numbers in the boxes) weree determined.
how does philosophy look at man
Answer:
The philosophical view of man implies that we are moral as well as intelligence beings. It provides the framework to discover the nature of human excellence embodied by the perennial virtues towards which all men of good will tend.
NEED HELP ON 31,32,33..ONLY IF YOU KNOW PLEASE
Answer:
31. C
32. D
33. B
Explanation:
31. A plant cell is an eukaryotic cell i.e. it contains a membrane-bound nucleus, located CENTRALLY. The nucleus is the largest organelle in the plant cell. The cell/plasma membrane bounds the cell while the chloroplast organelle (site of photosynthesis) is also located in the plant cell. Based on this description, the image in OPTION C is correct.
32. Pottasium (K) is a highly reactive group 1 element. As stated in this question, pottasium reacts vigorously with water (H2O). This reactive property of K element is due to its valence electrons. However, elements in the same group as pottasium i.e same column on the periodic table will have the same number of valence electrons, hence, will behave chemically similar. Therefore, elements in the same column as pottasium will react the same way with water.
33. A reactant is a an element/compound in a chemical reaction that gets used up to form new products. They are usually the starting materials located on the left side of any equation. In this equation shown as:
2CuO + C → 2Cu + CO2
CuO and C are the REACTANTS while Cu and CO2 are the products.
How many moles are in 2.3 x10^25 atoms of phosphorus
Answer:
38.21 molesExplanation:
To find the number of moles in a substance given it's number of entities we use the formula
[tex]n = \frac{N}{L} \\[/tex]
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question we have
[tex]n = \frac{2.3 \times {10}^{25} }{6.02 \times {10}^{23} } \\ = 38.20598...[/tex]
We have the final answer as
38.21 molesHope this helps you
Write a word or phrase beginning with each letter of the word GOLD that describes the properties of these gold coins
Periodic table is divided into three metals, non metals and metalloids. The metals are kept on the left side of the periodic table. Gold is a metal which exist in d block.
What is metal ?
Metals are those elements which is hard, conduct electricity, ductile, lustrous and malleable.
The properties of gold are:
1.Gold have free electrons that's why they can conduct electricity
2. Since atoms in Gold are very closely packed in a definite crystal so gold is solid. It is not brittle that is it can not be broken down easily
3. Gold does not react with water easily.
4.Gold is denser than water hence it sink in water.
Gold is a transition element. Gold is found in d block of periodic table. Its symbol is Au.
Therefore, Gold is a metal which exist in d block.
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What is the mass of 1 mol of Ca atoms to three significant Figures of CaSO4
Answer:
40g
Explanation:
Given parameters:
Number of moles = 1mol
unknown:
mass of Ca = ?
Solution:
The number of moles of a substance is related to mass using the expression below;
Mass = number of moles x molar mass
Molar mass of Ca = 40g/mol
So;
Mass of Ca = 1 mol x 40g/mol = 40g
A hockey player is wearing ice skates and pushes against the wall propelling her backward on the ice. According to Newton's third law of motion, which of the following best compares the forces acting between the wall and the hockey player?
A.
The forces are equal and applied against gravity.
B.
The forces are equal and applied in the opposite direction.
C.
The forces are different sizes and applied in the opposite direction.
D.
The forces are equal and applied in the same direction.
Answer:
The forces are equal and applied in the opposite direction
Explanation:
Study island 100
This is the chemical formula for acetic acid (the chemical that gives the sharp taste to vinegar): An analytical chemist has determined by measurements that there are moles of oxygen in a sample of acetic acid. How many moles of hydrogen are in the sample
Answer:
0.11 mol
Explanation:
This is the chemical formula for acetic acid (the chemical that gives the sharp taste to vinegar): CH₃CO₂H. An analytical chemist has determined by measurements that there are 0.054 moles of oxygen in a sample of acetic acid. How many moles of hydrogen are in the sample?
Step 1: Given data
Formula of acetic acid: CH₃CO₂HMoles of oxygen in the sample of acetic acid: 0.054 molesStep 2: Establish the appropriate molar ratio
According to the chemical formula of acetic acid, the molar ratio of H to O is 4:2.
Step 3: Calculate the moles of atoms of hydrogen
We will use the theoretical molar ratio for acetic acid.
0.054 mol O × (4 mol H/2 mol O) = 0.11 mol H
11. Silver ions can be precipitated from aqueous solutions by the addition of aqueous chloride:
KCl(aq) + AgNO3(aq) → AgCl(s) + KNO3(aq)
Silver chloride is virtually insoluble in water so that the reaction appears to go to completion. How many grams of solid KCl must be added to 25.0 mL of 0.125 M AgNO3 solution to completely precipitate the silver?
Answer:
0.2330 grams of solid KCl
Explanation:
In order to find KCl in grams, we need to convert from moles to moles to grams..
However, we are given the volume and the molarity, so first we will use that to convert to moles of AgNO3 (silver nitrate) and then use that to convert to moles of KCl and finally to grams of KCl..
-----------------------------------------------------------------------------------------------------------------
Step 1 -> We need to convert milliliters to liters
(25.0 ml)([tex]\frac{1 L}{1000 mL}[/tex]) = 0.025 L
Step 2 -> Convert from liters and molarity to just moles of AgNO3
(0.025 L)(0.125 [tex]\frac{moles AgNO_{3} }{1 ln soln}[/tex]) = 0.003125 moles [tex]AgNO_{3}[/tex]
**Liters cancel out, so just multiply across...
Step 3 -> Now that we have moles of AgNO3, we will convert to moles of KCl
We will do this using the balanced equation
We see that in the balanced equation, for every mol of AgNO3 that reacts, one mol of KCl will react too. So we will set the dimensional analysis up like the following:
(0.003125 moles AgNO3) * [tex]\frac{1 mol KCl}{1 mol AgNO3}= 0.00312 mol KCl[/tex]
Step 4-> So now that we have moles of KCl, we will just convert to grams
We will do this using the molar mass (atomic mass) of KCl to convert to grams
0.00312 mol KCl * [tex]\frac{74.5513 grams KCl}{1 mol KCl} = 0.2329728125 grams of KCl[/tex]
This can be rounded to 0.2330 grams of KCl
a mixture of of sand,salt and sawdust was stirred into water and the mixture was allowed to stand.
a)how might you collect "pure" sawdust?
b)what is the sediment which forms?
c)the clear liquid was poured off and divided into 2 parts.one part was evaporated,and the other was distilled.
i)what substance would be collected by distillation?
ii)what would be collected by evaporation?
iii)what difference in properties allows the separation in both evaporation and distillation?
Answer:
A) To get the pure sawdust u can filter it..
B) The muddy sagment that will form .
C) The clear liquid can divide into 3 layers on the top there will be pure water in middle there will be muddy or dark layer of water and in lower layer there will be the stones or heavy particles of water .
Under what conditions does a Lunar eclipse occur?
Answer:
when the Moon moves into the Earth's shadow
when the Sun, Earth, and Moon are exactly or very closely aligned with the Earth between the other two, and only on the night of a full moon
Explanation:
What is the molarity of a HCl solution that
contains 6.27 g of HCl in 163 mL of solution?
Answer in units of M.
Answer:
M = 1.04 M
Explanation:
Given data
Molarity of solution = ?
Mass of HCl = 6.27 g
Volume of solution = 163 mL (163 mL× 1L /1000 mL = 0.163 L)
Solution:
Molarity is used to describe the concentration of solution. It tells how many moles are dissolve in per litter of solution.
Formula:
Molarity = number of moles of solute / L of solution
Number of moles of HCl:
Number of moles = mass/molar mass
Number of moles = 6.27 g / 36.5 g/mol
Number of moles = 0.17 mol
Molarity:
M = 0.17 mol/ 0.163 L
M = 1.04 M
Answer:
4.6
Explanation:
The temperature of a 700. g bar of iron decreases by 30oC when the iron is plunged into 500. g of water. What is the temperature increase of the water, assuming that no heat is lost in the transfer?
Answer:
4.5 °C
Explanation:
According to the law of conservation of energy, the sum of the heat lost by the iron and the heat gained by the water is zero.
Qi + Qw = 0
Qi = -Qw [1]
We can calculate each heat using the following expression.
Q = c × m × ΔT [2]
where,
c: specific heat capacitym: massΔT: change in the temperatureReplacing [2] in [1], we get
ci × mi × ΔTi = -cw × mw × ΔTw
ΔTw = -ci × mi × ΔTi / cw × mw
ΔTw = -0.108 cal/g.°C × 700 g × (-30 °C) / 1 cal/g.°C × 500 g
ΔTw = 4.5 °C
Humans absorb oxygen from the air they breathe in and exhale carbon dioxide gas, CO2.Carbon dioxide gas is
A
an element made of carbon and oxygen atoms.
B
a solution made of carbon and oxygen atoms.
C
a compound of carbon and oxygen atoms.
D
a mixture of carbon and oxygen atoms.
Answer:
A
an element made of carbon and oxygen atoms.
So I think the answer is going to be A An element made of carbon and oxygen atoms.
Answer?? Hurry!!! Comment dadt
Answer:
The particles in the water are always moving
Explanation:
How many atoms is 9.8 moles of calcium
Answer:
How many grams is in 10.00 moles of calcium (Ca)? The number of atoms can also be calculated using Avogadro's Constant (6.02214179×1023) / one mole of substance.
Explanation:
Hope this helps
One method used commercially to peel potatoes is to soak them in a solution of NaOH for a short time and then remove them from the NaOH. The peel will have separated from the potato and so it can then easily be sprayed off to yield beautifully peeled potatoes! The NaOH solution however, must be analyzed periodically to make sure its concentration is adequate for the reaction In one such analysis, 45.7 mL of 0.500 M H2SO4 is required to react completely with a 20.0 mL sample of the NaOH solution. The products of the reaction are Na2SO4 and water. What is the concentration of the starting NaOH solution?a. 1.14 M b. 2.28 M c. 0.438 M d. 0.500 M e. 0.571M
Answer:
b. 2.28 M
Explanation:
The reaction of neutralization of NaOH with H2SO4 is:
2NaOH + H2SO4 → Na2SO4 + 2H2O
Where 2 moles of NaOH react per mole of H2SO4
To solve the concentration of NaOH we need to find the moles of H2SO4. Using the chemical equation we can find the moles of NaOH that react and with the volume the molar concentration as follows:
Moles H2SO4:
45.7mL = 0.0457L * (0.500mol/L) = 0.02285 moles H2SO4
Moles NaOH:
0.02285 moles H2SO4 * (2moles NaOH / 1 mol H2SO4) = 0.0457moles NaOH
Molarity NaOH:
0.0457moles NaOH / 0.020L =
2.28M
Right option:
b. 2.28 MThe concentration of the starting NaOH solution is:
b. 2.28 M
Neutralization reaction:
The reaction of neutralization of NaOH with H₂SO₄ is:
2NaOH + H₂SO₄ → Na₂SO₄ + 2H₂O
Calculation for concentration of NaOH:We need to find the moles of H₂SO₄. Using the chemical equation we can find the moles of NaOH.
Moles of H₂SO₄:
45.7mL = 0.0457L * (0.500mol/L) = 0.02285 moles of H₂SO₄
Moles of NaOH:
0.02285 moles H₂SO₄ * (2moles NaOH / 1 mol H₂SO₄) = 0.0457moles NaOH
Molarity of NaOH:
0.0457moles NaOH / 0.020L =2.28M
Thus, the concentration of the starting NaOH solution is: 2.28 M.
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help me plzz in chemistry
a) f2 loses electrons and is oxidised. li gains electrons and is reduced
c)sn2+ loses electrons and is oxidised.Al gains electrons and is reduced
b)br2 loses electrons and is oxidised. I- in KI gains electrons and is reduced
Calculate the molarity of a solution of potassium hydroxide if 19.55 mL of KOH is required for the titration of a 20.20 mL sample of a 0.3467 M sulfuric acid solution.
Answer:
The correct answer is 0.3582 M.
Explanation:
Based on the given information, the volume of KOH given is 19.55 ml, the volume of sulfuric acid given is 20.20 ml, and the molarity of sulfuric acid is 0.3467 M. There is a need to find the molarity of KOH.
The formula to use in the given case is,
M1V1 = M2V2
Here M1 is the molarity of KOH, V1 is the volume of KOH, M2 is the molarity of sulfuric acid, and V2 is the volume of H2SO4.
Here V1 is 19.55 ml, M2 is 0.3467 M, and V2 is 2020 ml.
Now putting the values in the equation we get,
M1 * 19.55 = 0.3467 * 20.20
M1 * 19.55 = 7.00334
M1 = 7.00334/19.55
M1 = 0.3582 M
Hence, the molarity of the given KOH is 0.3582.
The molarity of a solution of potassium hydroxide is 0.3582M
To get the molarity of the solution of potassium hydroxide KOH, we will apply the formula;
[tex]C_1V_1=C_2V_2[/tex]
C₁ and C₂ are the concentration of the solutionV₁ and V₂ are volumes of the solutionGiven the following parameters;
C₂ = 0.3467M
V₂ = 20.20mL
V₁ = 19.55mL
C₁ = ?
Substitute the given parameters into the formula:
C₁ × 19.55 = 0.3467× 20.20
C₁ × 19.55 = 7.00334
C₁ = 7.00334/19.55
C₁ = 0.3582M
Hence the molarity of a solution of potassium hydroxide is 0.3582M
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A desert area has many species of cactus and brush as well as birds, snakes, lizards, and rodents. This desert is an example of a
Answer: Climax Commuity.
Explanation: (hope it’s right! Good luck!)
Jasmine and her partner want to test to see if there is a relationship between how much of her solar panel is exposed to sunlight and how fast her solar car will move. She uses a piece of paper to cover the solar panel different amounts of her solar panel. The chart below shows the data she collected.
What is the independent or manipulated variable for this experiment?
The average of the trials
The speed in centimeters per second
The size of the solar panel
The amount of solar panel covered
Answer:
The amount of solar panel covered
Explanation:
The variable that is the independent one is the one that Jasmine is changing. In this case, it is the amount of solar panel covered, via a piece of paper.
Answer:
D: The amount of solar panel covered
Explanation:
If a radioactive substance has a half-life of 9 days what fraction of its original mass would remain after 27 days? *
Answer:
1/8
Explanation:
If the substance has a half-life of 9 days, that means that after 9 days, half of it will be left. So, after 18 days, one-fourth will be left. And after 27 days, 1/8 would be left. It's kind of like an exponential function, if that helps.
If a radioactive substance has a half-life of 9 days, the fraction of its original mass that would remain after 27 years will be 1/8.
What is half-life?Half-life is the time when a radioactive substance is decayed half.
If the radioactive substance has a half-life of 9 day. It means it will be decayed half after 9 days. The radioactive substance will be 1/4 decayed in 18 days. The substance will be 1/8 decayed in 27 days.
Thus, the correct option is 1/8 days.
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teeth to Bachile can be see more than once
Come as the chemical mantragen has the valence electrons each hydrogen has one walence electron, and chionner
Campie eles are for this went compound
.
NH H-
CI
ou
If I have 80 grams of H2 how many molecules of H2 do I have?
Answer:
2 molecules
Explanation:
I don't know how to explain it
The chemical formula of water is H₂O. Then 1 mole of water weighs 18 gram. Hence, 80 gram of water is equal to 4.4 mole.
What is chemical formula ?
Chemical element symbols, numbers, and occasionally other symbols like parentheses, dashes, brackets, commas, and plus and minus signs are used in a chemical formula to represent information about the chemical proportions of the atoms that make up a certain chemical compound or molecule.
It displays the constituent elements and how many atoms of each element are found in a single complex molecule. It also represents the compound's molecular weight.
Water has the chemical formula H₂O. Water weights 18 grams per mole. 80 grams of water are therefore equivalent to 4.4 moles.
Thus, The chemical formula of water is H₂O. 80 grams of H₂ contain 4.4 molecules of water.
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A red laser pointer emits light at a wavelength of 488 nm. If the laser emits 7.5 10–4 J of energy per second in the form of visible radiation, how many photons per second are emitted from the laser?
a)
4.1 10–19 photons/sec
b)
5.4 10–16 photons/sec
c)
8.9 1014 photons/sec
d)
1.8 1015 photons/sec
e)
2.5 1018 photons/sec
The answer to the question, how many photons per second are emitted from the laser is d. 1.84 × 10¹⁵ photons/sec
Since the red laser pointer emits light of wavelength 488 nm, we need to find the energy of each photon from
E = hc/λ where h = Planck's constant = 6.63 × 10⁻³⁴ Js, c = speed of light = 3 × 10⁸ m/s and λ = wavelength of light = 488 nm = 488 × 10⁻⁹ m
Substituting the values of the variables into the equation, we have
E = hc/λ
E = 6.63 × 10⁻³⁴ Js × 3 × 10⁸ m/s ÷ 488 × 10⁻⁹ m
E = 19.89 × 10⁻²⁶ Jm ÷ 488 × 10⁻⁹ m
E = 0.04076 × 10⁻¹⁷ J per photon
E = 4.076 × 10⁻¹⁹ J per photon
Since the laser emits 7.5 × 10⁻⁴ J per second, the number of photons emitted from the laser per second = energy per second/energy per photon
= 7.5 × 10⁻⁴ J per second ÷ 4.076 × 10⁻¹⁹ J per photon
= 1.84 × 10¹⁵ photons/sec
The answer to the question, how many photons per second are emitted from the laser is d. 1.84 × 10¹⁵ photons/sec
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27. The compound having only primary hydrogen atoms is ( ).
(A) isobutene
(B) 2,3-dimethylbutene
(C) cyclohexane
(D) propyne
Answer:
The correct answer is - (a) isobutene.
Explanation:
A 1° or primary hydrogen atom is one that is bonded to a 1° carbon atom; a 2° hydrogen atom is one that is connected to a 2° carbon atom; In isobutene only among all the all option having only primary hydrogen atoms. rest have secondary or teritary hydrogen atoms in them
C1∘H3≡CH: (only 1∘ hydrogen atoms)
A pure substance composed of two or more different elements is aln)
a. ion
b. heterogeneous mixture
c. chemical compound
d. solid
e. solution
chemical compound
Answer:
c
Explanation:
that is my dads answer
A pure substance composed of two or more different elements is a chemical compound.
When two or more atoms are chemically combined, we refer to such a combination as a chemical compound.
Since a chemical compound contains only a given set of elements which are chemically combined together, a chemical compound is also a pure substance.
Hence, a pure substance composed of two or more different elements is a chemical compound.
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