Answer: 10 half-lives have passed.
Explanation:
What is the percentage of water in the following compound? answer using one decimal place. sodium carbonate decahydrate, na2co3 • 10h2o % by mass h2o
The percentage by mass of water in Na2CO3.10H2O from the calculation is 62.9%
What is percentage by mass?The term percentage by mass refers to the amount of a particular moiety by mass in a molecule.
In this case, we know that the molar mass of Na2CO3.10H2O is 286 g/mol the molar mass of the 10 moles of water is 180 g/mol hence the percentage by mass of water in the compound is; 180 g/mol /286 g/mol * 100/1 = 62.9%
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Answer:
63.0
Explanation:
got it wrong so it told me the answer
Some greenhouse gases, such as fluorocarbons (CFCs, HFCs, PFCs, etc.), are human-made. Others, such as water, methane, and carbon dioxide, are naturally produced. Which type of greenhouse gas (human-made or natural) is more difficult to control and eliminate?
Which types are easier? In three to five sentences, provide evidence for your argument.
Wetlands are able to remove nutrients and chemicals from water as the water flows through the area. A developer is planning to destroy most of the wetlands near a bay. In three to five sentences, explain how destroying the wetlands would impact the bay’s water quality and ecosystem.
Carbon dioxide (CO2) is the hardest human-made greenhouse gas to control because it is released with cellular respiration.
What are greenhouse gases?Greenhouse gases are gases that trap solar radiation and increase the temperature on the Earth's surface.
The easier human-made greenhouse gases to control are chlorofluorocarbons because they can be substituted in the industry by other materials.
The destruction of the wetlands would impact the bay’s water quality and ecosystem because these areas contain pure water required for the whole ecosystem.
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What happens when a catalyst is used in a reaction?.
When a catalyst is used in a reaction then it alter the rate of the reaction.
What is catalyst?Catalyst are those species which are added on the reaction to alter the rate of the reaction without being involved in the reaction.
Catalyst are of two types:
Positive catalyst: It increases the rate of the reaction.Negative catalyst: It decreases the rate of the reaction.Hence, catalyst is used to change the rate of the reaction.
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Convert 2500 calories to kilocalories or nutritional calories
Answer:
2.5 kilo calories
Explanation:
1 Calories = 0.001 Kilocalories
10 Calories = 0.01
Kilocalories 2500
Calories = 2.5 Kilocalories
Answer:
2.5 kilocalories.
Explanation:
2500 divided by 100 to get to kilo is 2.5
Which of the designations are accurate for the fatty acid?.
Answer:
Fatty acid is considered unsaturated if it contains at least one double bond. It is called monounsaturated if it contains one double bond and polyunsaturated if it contains more than one double bond.
Explanation:
i hope i helped you
which of the following pairs would have larger size ? Explain your answer
a) k or k+
b) Br or Br-
c) O2- or F-
Answer:
k
br-
o2- ion
Explanation:
a/k ion has a larger size than k+ ion bc of the size of the radius it is always smaller compared to the parent ion .
b/bc it is an anion and it always has a large size compared to the parent ion (the same thing as the first one)
c/both the anions are isoelectornic species .Since the nuclear charge of O2- ions is small,its size is therefore more than the F- ion
Describe the properties of the transuranium elements.
Nuclear properties. Isotopes of the transuranium elements are radioactive in the usual ways: they decay by emitting alpha particles, beta particles, and gamma rays; and they also fission spontaneously. The table lists significant nuclear properties of certain isotopes that are useful for chemical studies.
hope this helps
Please answer these. It's part of Quantitave Chemistry. Calculating limiting raegents
The limiting reactant refers to the reactant that is in small amount. The extent of the reaction depends on the amount of the limiting reactant.
What is limiting reactant?The term limiting reactant refers to the reactant that is in small amount, We shall now solve the questions individually.
1) The reaction equation is;
CaO + H2O → Ca(OH)2
Number of moles of CaO = 10 g/56 g/mol = 0.18 moles
Number of moles of H2O = 10 g/18 g/mol = 0.56
Since the reaction is 1:1, CaO is the limiting reactant
Mass of calcium hydroxide = 0.18 moles * 74 g/mol = 13.32 g
2) The reaction equation is;
Mg + Br2 → MgBr2
Number of moles of Mg = 1 g/24 g/mol = 0.042 moles
Number of moles of Br2= 5 g/160 g/mol = 0.031 moles
Since the reaction is 1:1, Br2 is the limiting reactant
Mass of MgBr2 = 0.031 moles * 184 g/mol = 5.7 g
3) The reaction equation is;
CuO + H2 → Cu + H2O
Number of moles of CuO= 2.00 g/80 g/mol = 0.025 moles
Number of moles of H2 = 1.00g/2 g/mol = 0.5 moles
Since the reaction is 1:1, CuO is the limiting reactant
Mass of Cu = 0.025 moles * 63.5 g/mol = 1.59 g
4) The reaction equation is;
2Na + F2 → 2NaF
Number of moles of Na = 2.30 g/23 g/mol = 0.10 moles
Number of moles of F2 = 2.85 g/38 g/mol = 0.075 moles
If 2 moles of Na react with 1 mole of F2
x moles of Na reacts with 0.075 moles of F2
x = 0.15
Hence Na is the limiting reactant
Mass of NaF = 0.10 moles * 42 g/mol = 4.2 g
5) The equation of the reaction is;
Fe2O3 + 2Al → 2Fe + Al2O3
Number of moles of Fe2O3 = 8.00 g/160 g/mol = 0.05 moles
Number of moles of Al = 2.16 g/27 g/mol = 0.08 moles
If 1 mole of Fe2O3 reacts with 2 mole of Al
x moles of Fe2O3 reacts with 0.08 moles of Al
x = 0.04 moles
Hence, Fe2O3 is the limiting reactant
1 mole of Fe2O3 yileds 2 moles of Fe
0.05 moles yileds 0.05 moles * 2 moles/1 mole = 0.1 moles
Mass of Fe = 0.1 moles * 56 g/mol = 5.6 g
6) The equation of the reaction is;
2Al + 3Cl2 → 2AlCl3
Number of moles of Al = 13.5 g/27 g/mol = 0.5 moles
Num ber of moles of Cl2 = 42.6 g /71 g/mol = 0.6 moles
If 2 moles of Al reacts with 3 moles of Cl2
x moles of Al reacts with 0.6 moles of Cl2
x = 0.4 moles
Al is the limiting reactant
Mass of AlCl3 = 0.4 moles * 133 g/mol = 53.2 g
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A 748 L hot air balloon sits on a table at 26.7oC. If the balloon is heated to 48.3oC, what is the new volume?
The new volume of the hot air balloon is 801.9L.
As the temperature of the hot air balloon on the table is increased, the its volume also increases.
Charle's lawCharle's law states that the volume of an ideal gas is directly proportional to the absolute temperature provided pressure is kept at constant.
It is expressed as;
V₁/T₁ = V₂/T₂
Given the data in the question;
Initial volume V₁ = 748LInitial temperature T₁ = 26.7°C = 299.85KFinal temperature T₂ = 48.3°C = 321.45KFinal volume V₂ = ?To calculate the new volume we subtsitute our given values into the expression above.
V₁T₂ = V₂T₁
V₂ = V₁T₂ / T₁
V₂ = ( 748L × 321.45K ) / 299.85K
V₂ = 240444.6LK / 299.85K
V₂ = 801.9L
The new volume of the hot air balloon is 801.9L.
As the temperature of the hot air balloon on the table is increased, the its volume also increases.
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Hypobromous acid (HOBr) is produced in the blood and has properties that combat pathogens. It is also used in bleaches and other cleaning products. The following is a reversible reaction:
HOBr → H+ + OBr–
a. Write the equation you would use to calculate the Ka of this reaction.
b. If [H+] at equilibrium is 9. 1 × 10–6, what is the Ka of the reaction, given a final HOBr concentration
of 0. 33 M?
From the calculations in the question, we have that the dissociation constant is 2.5 * 10^-10.
What is Ka?The term Ka has to do with the acid dissociation constant and it is obtained from; Ka = [H+] [OBr–]/[HOBr]
Now, we are told that the hydrogen ion concentration at equilibrium is 9. 1 × 10–6 and the HOBr concentration is 0.33 M, it the follows that;
Ka = (9. 1 × 10–6)^2/ 0.33
Ka = 2.5 * 10^-10
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Giving brainliest, please HELP!
Answer:
C!
Explanation: Makes since brainlist please!
What is the final step in scientific polling?
A. interpreting the results
B. selecting the sample
C. presenting carefully worded questions
D. identifying the universe
Answer:select and control A. interpreting the results
Explanation:
Why are intermolecular forces generally much weaker than bonding forces?.
Explanation:
Intermolecular forces: These are the attractive or repulsive forces acting between two molecule in interaction.
The attractive forces between molecules are of several types based on the interaction between molecules also known as Vander wall forces.
Bonding forces: They are also attractive forces acting between two constituents (atom, ion, radicals etc) and stabilizes the constituent particles by loss of energy. The bond between any two species are formed by the overlapping of corresponding orbitals.
Whenever positive overlapping occurs between species, the formation of Bonding molecular orbital (BMO) takes place. and when electron enters into BMO it loses energy. Alternative form of explaining the concept is Individual electron possess more energy than the electrons that paired or Bonded.
Now coming to your question,
All the intermolecular forces are formed by weak attractive forces (vanderwall forces) which includes Ion-dipole forces, Ion-induced-dipole forces, Dipole-dipole forces, Dipole-induced-dipole forces, Hydrogen bonds & London forces.
All these forces are temporary and weak, and formed by the poles generated on molecule due to shift of electron, for e.g. Any molecule having more electron at one pole and less electron at another pole then that molecule start acting as charged body when that charged body comes in contact with opposite pole of another charged body the interaction takes place, since the electrons are dynamic and unsteady it's not possible that the pole will keep acting same as before. hence the intermolecular forces are generally weaker.
On the other side the Bonding electrons, are formed by the various strong overlapping such as between Head to Head overlapping leads to formation of Sigma bond which is the strongest bond takes alot of Energy to break & Lateral overlapping lead to formation of pi bond which is also stronger bond than that of Hydrogen bond.
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What is the Molecular Formula for Fiber?
Answer:
Description. Dietary fiber is mostly derived from the plant cell wall. It mainly includes cellulose, hemicellulose, pectic polysaccharides, oligosaccharides, resistant starch, and lignin.
Explanation:
I hope help you and thanks for heart and rate my answer
The brain and spinal cord work together to allow the body to think and react to the environment.
What is the spinal cord?
a cell
a tissue
an organ
an organ system
Answer:
B . a tissue
Explanation:
What else can you use besides vinegar for dying eggs?.
You can use lemon or lime juice as a 1 to 1 replacement for vinegar in egg dye recipes.
For example, if the recipe calls for 1 teaspoon (4.9 mL) of vinegar, use 1 teaspoon (4.9 mL) of lemon or lime juice.
You can use fresh or bottled lemon or lime juice. Both will work the same way.
Hope this helps :))
Devices that are made to replace injured or damaged body parts are called
• A. Prosthetic devices
• B. Scaffolds
C. Genetically engineered devices
D. Artificial intelligence
Answer:
Prosthetic Devices
Explanation:
I’m a genius and it’s the answer :D
what is magnetism?explain any three evidence that support terrestrial magnetism.
Answer:
Magnetism is the force exerted by magnets when they attract or repel each other.
For Evidence of terrestrial magnetism
When a magnetic body is buried inside the earth in a North-South direction, it gets magnetized due to the effect of terrestrial magnetism. A freely suspended magnet faces a North-South direction
Explanation:
The reason why magnetism acts this way is caused by the motion of electric charges. Every substance is made of tiny units called atoms. Each atom contains electrons, particles that carry electric charges.
I really hope this helps you.
g. Name a separating method for each of the question. (3)
I. Sodium chloride from the sodium chloride salt solution
II. Pure water from the sea water
III. Sand from the mixture of sand and salt solution
If the order of a reaction with the regard to reagent A is 2, when the concentration of A doubles, the rate will
Answer:
Rate will double
Explanation:
Since the concentration of A is doubling the rate of reaction will also double, since in this scenario concentration is proportional to rate of reaction. So if the concentration of A were to triple the rate of reaction would also triple.
How much grams of sucrose (C12H22O11) do you need to get one kilogram of invert sugar?
Answer:
You would need 85.5 g
Explanation:
Molarity=Moles of soluteVolume of solution (in litres)0.25 M=n1 Ln = 0.25 molSo, we need 0.25 mol of sucrose to make 0.25 M solution.Molar mass of sucrose (C12H22O11)=342 g/mol Mass of 0.25 mol sucrose is0.25mol×342gmol=85.5 g
Explanation:
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Have A Great Day
~Zero~
Use the information in the table to describe the temperature-vs.-time diagrams.
Which number on the graph represents a solid?
Which number on the graph represents the phase change melting?
Which number on the graph represents the phase change boiling?
Answer:
Have to give me more a little more information
Explanation:
Answer:
answer in picture
Explanation:
What is the molecular formula of a compound with an empirical formula of ch and a molar mass of 78. 1 g/mol?.
Answer:
answer is in the explanation
Explanation:
Answer. Explanation: ->So, molecular formula = (CH)n = (CH)6 =C6H6; in this case we substituted the calculated value of n. ->Therefore, the molecular formula of the compound having the molecular weight 78 g/mol is (D) - C6H6.
Give an example of a change that the ecosystem was able to recover from and return to equilibrium.
Answer:
The Fox is at the top of the food chain; so, the other animals could increase in population and the fox could return
Moderate drought is an illustration of a shift that the prairie ecosystem was able to adapt to and return to balance. The amount of water that is accessible to both plants and animals reduces during a drought, which affects both plant development and the number of herbivores.
A forest ecosystem can recover from fire because diverse creatures play distinct functions in various ways and locations. Many species' dispersed habitats enable them to resprout or grow from seeds that are ignited by fire, protecting populations from being entirely wiped off.
Ecosystems are living things that are susceptible to a wide range of abiotic and biotic perturbations brought on by the forces of nature and/or human activities.
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Why can ionic table salt and covalent rubbing alcohol both dissolve in water?
Answer:
please don't trust those scam links
Who developed the first scientific atomic theory?
Answer:
John Dalton
Explanation:
John Dalton (1766-1844) is the scientist credited for proposing the atomic theory. This theory explains several concepts that are relevant in the observable world.
Given the following reaction: 2NH3(g) + 3Cl2(g) → N2(g) + 6HCl(g)? How many grams of chlorine must react to produce 16 L of nitrogen gas at 1.2 ATM and 23 °C?
Consider the N₂ gas produced:
Pressure, P = 1.2 atm
Volume, V = 16 L
Gas constant, R = 0.08206 L atm / (mol K)
Temperature, T = (273 + 23) K = 296 K
Gas law: PV = nRT
Then, n = PV/(RT)
No. of moles of N₂, n
= 1.2 × 16 / (0.08206 × 300)
= 0.79 mol
According to the given equation, mole ratio Cl₂ :
N₂ = 3 : 1
No. of moles of Cl₂ needed
= (0.79 mol) × 3
= 2.37 mol
Mass of Cl₂ needed
= (2.37 mol) × (35.5 × 2 g/mol)
= 168 g
How many grams of nickel would be electroplated by passing a constant current of 7.2 A through a solution of NiSO4 for 90.0 min
The amount of nickel that would be electroplated by passing a constant current of 7.2 A through a solution of NiSO₄ for 90 min is 11.83g.
How much charge will be deposited by equivalent mass?Equivalent mass of any substance will be electroplated by 96485 coloumb of charge.
Equivalent mass of Ni in NiSO₄ = 58.7/2 = 29.35g
So that 96485 coloumb of charge = deposited 29.35g of Ni
Also charge will be calculated by usimg the below equation as:
Q = (I)(t), where
I = current = 7.2 ampere
t = time = 90 min = 5400 sec
Q = (7.2)(5400) = 38,880 coloumb
By using both the equations of coloumb, we calculate the grams of Ni electroplated by 38,880 coloumb charge as:
Mass of Ni = (29.35g)(38,880/96,485)
Mass = 11.826 grams = 11.83g
Hence required mass of nickle is 11.83 grams.
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SnO2 + 2H2Sn + 2H2O
If you form 42.5g of H2O from the above reaction, how many moles of H2 were present at
the start of the reaction
Answer: 2.36 moles
Explanation:
Using 1 g/mol for the atomic mass of hydrogen and 16 g/mol for the atomic mass of oxygen, we get that the gram-formula mass of water is 1(2)+16=18 g/mol. Thus, 42.5 grams of water is the same as 2.36 moles.
From the reaction, we know that for every 2 moles of water produced, 2 moles of dihydridotin are consumed. In each mole of dihydridotin, there is 1 mole of hydrogen, meaning that 2 moles of hydrogen are consumed.
Thus, the answer is 2.36 moles.
Explain what "LEO the lion goes GER" means based upon what you have learned
"LEO the lion goes GER" means based upon the oxidation and reduction reactions.
What is oxidation and reduction reaction?Oxidation reactions are those reactions in which lossing of electrons are taking place from the substrate molecule and in reduction process gaining of electrons is done by substrate molecules.
The phrase "LEO the lion goes GER" is used in the context of oxidation and reduction reactions. Meaning of the terms:
LEO → Lose electrons = oxidation
GER → Gain electrons = reduction
Hence the given line is based on oxidation and reduction.
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Answer:
Leo: lose electron(s) = oxidation. Ger: gain electron(s) = reduction.
Explanation: