Answer:
C) C₆H₁₂O₆.
Explanation:
We can determine the molecular formula by calculating the molecular mass of different choices.Molecular mass = ∑(no. of atoms * atomic mass).
A) CH₂O:
molecular mass = atomic mass of C + 2*atomic mass of H + atomic mass of O = (12.0 g/mol) + (2 * 1.0 g/mol) + (16.0 g/mol) = 30.0 g/mol.
B) C₃H₈O₃:
molecular mass = 3(atomic mass of C) + 8(atomic mass of H) + 3(atomic mass of O) = 3(12.0 g/mol) + 8(1.0 g/mol) + 3(16.0 g/mol) = 92.0 g/mol.
C) C₆H₁₂O₆:
molecular mass = 6(atomic mass of C) + 12(atomic mass of H) + 6(atomic mass of O) = 6(12.0 g/mol) + 12(1.0 g/mol) + 6(16.0 g/mol) = 180.0 g/mol.
D) C₈H₁₆O₈:
molecular mass = 8(atomic mass of C) + 16(atomic mass of H) + 8(atomic mass of O) = 8(12.0 g/mol) + 16(1.0 g/mol) + 8(16.0 g/mol) = 240.0 g/mol.
So, the right choice is: C) C₆H₁₂O₆.
The molecular formula of the compound is the C₆H₁₂O₆. The correct option is C.
The empirical formula of the fructose and the glucose = CH₂O
The molecular mass of the compound = 180.15948 g/mol
The empirical formula mass of the molecule, CH₂O = 12 + 2(1) + 16 = 30 g/mol
The number of empirical formula units = 180.15948 g/mol / 30 g/mol
The number of empirical formula units = 6
The molecular formula of the compound = 6( CH₂O)
The molecular formula of the compound = C₆H₁₂O₆
Therefore, the molecular formula of the compound is C₆H₁₂O₆. The option C is correct.
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Na2O How many atoms of each element are in this compound? A. 2 sodium atoms and 1 oxygen atom B. 2 sodium atoms and 2 oxygen atoms C.1 sodium atoms and 1 oxygen atoms D.1 sodium atom and 2 oxygen atoms
Answer:
A
Explanation:
There are 2 sodium atoms and 1 oxygen atom.
In Na2O, there are 2 sodium atoms and 1 oxygen atom, as indicated by the chemical formula, which represents a 2:1 ratio of sodium to oxygen with an overall neutral charge.
The compound Na2O consists of two elements: sodium (Na) and oxygen (O). According to the chemical formula, for every one unit of this compound, there are two sodium atoms and one oxygen atom. This is because the subscript '2' next to Na in the formula indicates there are two sodium atoms, while the absence of a number next to O implies there is one oxygen atom. Hence, in the compound Na2O, the ratio of sodium to oxygen atoms is 2:1, which is due to the need for the number of electrons lost by sodium (each Na atom loses one electron) to equal the number of electrons gained by oxygen (the O atom gains two electrons) and ensure the compound has an overall neutral charge. Therefore, the correct answer is A: 2 sodium atoms and 1 oxygen atom.
Green plants use light from the sun to drive photosynthesis. photosynthesis is a chemical reaction in which water (H2O) and carbon dioxide (CO2) chemically react to form the simple sugar glucose (C6H12O6) and oxygen gas (O2). What mass of water is consumed by the reaction of 7.3 g of carbon dioxide?
Answer:
Mass of H₂O is 3.0g
Explanation:
The reaction equation is given as:
6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂
Parameters that are known:
Mass of CO₂ used = 7.3g
Unknown: mass of water consumed = ?
Solution
To solve this kind of problem, we simply apply some mole concept relationships.
First, we work from the known to the unknown. From the problem, we have 7.3g of CO₂ that was used. We can find the number of moles from this value using the expression below:Number of moles of CO₂ = [tex]\frac{mass}{molar mass}[/tex]
From this number of moles of CO₂, we can use the balanced equation to relate the number of moles of CO₂ to that of H₂O:6 moles of CO₂ reacted with 6 moles of H₂O(1:1)
We can then use the mole relationship with mass to find the unknown.Workings
>>>> Number of moles of CO₂ =?
Molar mass of CO₂ :
Atomic mass of C = 12g
Atomic mass of O = 16g
Molar mass of CO₂ = 12 + (2 x16) = 44gmol⁻¹
Number of moles of CO₂ = [tex]\frac{7.3}{44}[/tex] = 0.166moles
>>>>>> if 6 moles of CO₂ reacted with 6 moles of H₂O, then 0.166moles of CO₂ would produce 0.166moles of H₂O
>>>>>> Mass of water consumed = number of mole of H₂O x molar mass
Mass of H₂0 = 0.166 x ?
Molar mass of H₂O:
Atomic mass of H = 1g
Atomic mass of O = 16
Molar mass of H₂O = (2x1) + 16 = 18gmol⁻¹
Mass of H₂O = 0.166 x 18 = 3.0g
Answer:
The mass of water when it is reacted with [tex]7.3[/tex]g of carbon dioxide is [tex]3[/tex]g.
Explanation:
Given:
Green plants use light from the sun to drive photosynthesis.
sugar glucose:
[tex](C_6H_1_2O_6)[/tex]
oxygen gas:
[tex](O_2)[/tex]
Step 1:
To find the mass of water is consumed by the reaction of [tex]7.3[/tex] g of carbon dioxide
Let,
Mass of water consumed = number of mole of [tex]H_{2} O[/tex] x molar mass
First we have to find molar mass,so
Number of moles of [tex]CO_{2}[/tex][tex]=\frac{mass}{molarmass}[/tex]
Molar mass of [tex]CO_{2}[/tex]Atomic mass = g
Molar mass
= [tex]12 + (2 x16)[/tex]
[tex]=44gmol^{-1}[/tex]
Therefore,Number of moles of
[tex]$\mathrm{CO}_{2}=\frac{7.3}{44}[/tex]
[tex]=0.166 \mathrm}$[/tex]moles
Step 2:
Now we have to find,
Molar mass of [tex]$\mathrm{H}_{2} \mathrm{O}$[/tex]
Atomic mass of [tex]{H\mathrm $}=1 \mathrm{~g}$[/tex]
Atomic mass of [tex]$O=16$[/tex]
Molar mass of
[tex]$\mathrm{H}_{2} \mathrm{O}=(2 \times 1)+16[/tex]
[tex]=18 \mathrm{gmol}^{-1}$[/tex]
Step 3:
Substitute in the formula,
Mass of [tex]H_{2}O[/tex] = [tex]0.166[/tex]x [tex]18[/tex] = [tex]3.0[/tex]g
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How would the measured ph of the diluted material compare to the ph of the original undiluted sample?
Answer:
It would become more neutral when diluted
Explanation:
Assuming you dilute it with water, the more diluted the substance, the more neutral (and closer to 7), it would be. Ie straight lemon juice is more acidic than lemonade, which is more acidic than water. I hope this helps :)
The pH of a diluted sample would usually be higher than that of the undiluted original, due to the lesser concentration of hydrogen ions in the diluted sample. During titration, there are three main states - initial, pre-equivalence and post-equivalence - and the pH behaves differently in each of these states.
Explanation:The measured pH of a diluted sample would be higher compared to the pH of the original undiluted sample. This is because when a solution is diluted, it has a lower concentration of hydrogen ions (H+), which means it is less acidic and in turn, has a higher pH.
In the initial state, the pH is determined by the acid being titrated. If you have two samples that are equally concentrated; a weaker acid will have a higher initial pH compared to a stronger one.
At the pre-equivalence point (where the volume of added titrant is between 0 and 25 mL), the solution’s pH increases gradually as the acid reacts with added titrant. The observed solution will include unreacted acid and its reaction product, its conjugate base. At the equivalence point one observes a drastic rise in pH as the transition happens from acidic to either neutral (for strong acid sample) or basic (for weak acid sample).
Post-equivalence, the pH is determined by the amount of excess strong base titrant added. Similarly with the increase in volume of the added titrant (> 25 mL), you would notice that the titration curves of the two samples will look quite similar.
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What should one avoid if they are suffering from acid reflux (too much acid in the body)? (Choose all that apply)
Tomato juice
Black coffee
Lemon juice
Orange juice
Answer:
- Tomato juice
- Lemon juice
- Orange juice
Explanation:
If someone is suffering from acidic reflux then it would be for the best if that person avoids food and drinks that can contribute to even higher acidic content in that person's organism. The easiest way to know what should be avoided is to get informed about the Vitamin C content of the foods and drinks. The fruits in general are something that should be avoided in this kind of circumstances, especially the tomatoes, lemons, and oranges, as they are highly acidic, so any products from them, especially in the form of juice, should be avoided.
The molar mass of an element is the mass of one
Answer:
The molar mass of an element is the mass of one mole of atoms of the element.Explanation:
The molar mass of an element is its atomic mass, i.e. the mass in grams of one mole of atoms of the element.
Remember 1 mol is approximately 6.022 × 10²³.
So, 1 mol of atoms is 6.022 × 10²³ atoms.
The molar mass is an average: it is the weighted average mass of the natural isotopes of the element, taking into account their relative abundance.
For example, the molar mass or atomic mass of carbon is 12,0107 g/mol, instead of 12.0000, becasue carbon exists in several forms (isotopes), and so the weighted average is not a whole number.
Radioactive iodine-131 has a half-life of eight days. The amount of a 200.0 gram sample left after 32 days would be
Answer:
12.5 g
Explanation:
Nuclear half-life,
t
1/2
, is the amount of time required for a quantity of a radioactive material to fall to half its value as measured at the beginning of the time period.
Iodine-131 is a radioactive isotope with a half-life of 8 days. After 32 days, or four half-lives, the original 200 gram sample of iodine-131 would decay leaving only 12.5 grams of the radioactive isotope.
Explanation:The subject of your question falls under Physics, particularly in the area of nuclear chemistry, where we study radioactivity and nuclear decay. In your case, you're talking about Iodine-131, a radioactive isotope with a half-life of 8 days.
The half-life concept means that, in a given time period, half of the initial sample would have decayed. Here, you have an initial amount of 200 grams, and after four half-lives (since 32 days is 4 times the half-life of 8 days), only 1/16th of the original sample is undecayed because the material halves each time (1/2 after 1 half-life, 1/4 after 2 half-lives, 1/8 after 3 half-lives, and so forth).
Accordingly, after 32 days, or four half-lives, 200 grams of Iodine-131 would reduce to 200/16 = 12.5 grams.
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Hydrocarbons that have one or more double or triple bonds are _____.
A. unsaturated
B. saturated
C. aromatic
D. substituted
Answer:
A. Aromatic
Explanation:
Answer: A. unsaturated
Explanation:
Saturated hydrocarbons are defined as the hydrocarbons in which a single bond is present between carbon and carbon atoms. The general formula for these hydrocarbons is [tex]C_nH_{2n+2}[/tex]
Unsaturated hydrocarbons are defined as the hydrocarbons which have double or triple covalent C-C bonds. They are known as alkenes and alkynes respectively. The general formula for these hydrocarbons is [tex]C_nH_{2n}[/tex] and [tex]C_nH_{2n-2}[/tex]
Aromatic hydrocarbons are those hydrocarbons in which Huckel's rule [tex](2n+2)\pi[/tex] is obeyed. Example: Benzene
Substituted hydrocarbons are those hydrocarbons in which hydrogen is replaced by some other element. Example: [tex]CH_3Cl[/tex]
The characteristic functional groups of a protein are _____.
Answer:
[tex]\boxed{\text{amide groups}}[/tex]
Explanation:
A protein is a long chain of amino acids linked together by amide groups.
The general structure is
[tex]\rm \left[-NHCHR-\underbrace{\hbox{CO-NH}}_{\hbox{amide group}}-CHRCO-\right]_{n}[/tex]
What is another name of a chain of amino acids
Answer:
Amino acids are the structural units (monomers) that make up proteins. They join together to form short polymer chains called peptides or longer chains called either polypeptides or proteins.
Explanation:
These polymers are linear and unbranched, with each amino acid within the chain attached to two neighboring amino acids.
A protein is made up of one or more polypeptide chains are chains of amino acids, whose sequence is encoded by a gene.
What is protein ?A structure composed of amino acids. The body need proteins to operate correctly. They serve as the building blocks for several bodily components, including the skin, hair, and enzymes, cytokines, and antibodies.
These amino acids are arranged in a long chain and joined to one another by covalent peptide bonds to form proteins. Consequently, polypeptides are another name for proteins.
The substances known as amino acids, or the "building blocks of proteins," serve a variety of vital functions in your body.
Thus, protein is made up of one or more polypeptide chains are chains of amino acids, whose sequence is encoded by a gene.
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At what stage of a chemical reaction is chemical energy at its highest level?
In any chemical reaction, value of chemical energy is highest at the threshold energy point.
What are chemical reactions?Chemical reactions are those equations in which reactants combine with each other for the formation of the products.
During the process of a chemical reaction, an intermediate complex is formed in which bonds of reactant as well as of products are present and it is most unstable because of high potential energy. This complex is formed at the threshold energy point which is the highest energy level of any chemical reaction.
Hence threshold energy is the highest energy level.
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s it possible for several scientists who have never met each other to contribute to the same scientific knowledge, theory, or law?
Explain your answer. (4 points)
Answer:
Yes
Explanation:
People in the same scientific field quickly come to know one another because they publish the same sort of articles in journals that are dedicated to their field.
Their experiments and findings are immediately understood by others reading the journal. Its a case of news travels fast, especially when the news is known to everyone.
If you were given two transparent liquids how would you determine which is pure and which is salt water
Select the atoms that belong to the same element
Answer:Top Right and Bottom Right.
Explanation:
Proton's define an elements Identity
Answer: The atoms which belong to the same element are atom 2 and atom 5.
Explanation:
Elements are identified by their atomic numbers.
Atomic number is defined as the number of protons or number of electrons that are present in an element.
Atomic number = Number of protons = Number of electrons
Two atoms having same number of protons will belong to same element.
From the given image, atom 2 and atom 5 have same number of protons which are 11.
Thus, both the atoms belong to same element.
Hence, the correct answer is atom 2 and atom 5.
#15 fill in the following table regarding ions
Answer:
[tex]P^{3-}[/tex] Anion Gained 3 18
[tex]Sr^{2+}[/tex] Cation Lost 2 36
[tex]Fe^{3+}[/tex] Cation Lost 3 23
Explanation:
Looking at the ionic notation, the negative symbol (-) indicates that there are more electrons than protons and the positive symbol (+) indicates that there are more protons than electrons.
The number tells you how many was gained or lost.
To determine how many electrons are left, you base this off how many protons there are. The number of protons in an atom is expressed by the atomic number. In a stable atom, you have an equal number of protons and electrons.
Ions occur when electrons are gained or lost.
A cation is positively charged because it LOST an electron. Since there are more protons than electrons, the charge would be positive.
An anion is negatively charged because it gained an electron. Since there are more electrons than protons, the charge would be negative.
Using the explanation above, you can see how the answers were obtained. As for the last column, just use basic math to do this.
The atomic number of Phosphorus (P) is 15, so this means that there are 15 protons. Since it gained 3 electrons, just add 3 to 15:
15 + 3 = 18
Sr has an atomic number 38. Since it lost 2 electrons, just subtract 2 from the atomic number.
38-2 = 36
Fe has an atomic number 26. It lost 3 electrons, so we subtract again.
26-3 = 23
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Amanda was asked to make a solution of salt water using 32.0 grams of NaCl and 0.75 Liter of water. Amanda realized that first, she needed to find the number of moles there are in 32 grams of NaCl. She set up the following calculation to find the number of moles of NaCl.
32.0 g NaCl x 1 mole NaCl = 0.55 moles of NaCl
58.45 g NaCl
A. Did Amanda find the number of moles of NaCl correctly? If not, explain.
B. What does Amanda need to do next to calculate the molarity of the NaCl solution? Show your work for full credit.
Answer:
A. Yes, Amanda find the number of moles of NaCl correctly.
B. 0.73 M.
Explanation:
A. Did Amanda find the number of moles of NaCl correctly? If not, explain.
Yes, Amanda find the number of moles of NaCl correctly.The relation to find the no. of moles of NaCl is:No. of moles (n) of NaCl = mass/molar mass.
mass of NaCl = 32.0 g, molar mass of NaCl = 58.45 g/mol.
∴ No. of moles (n) of NaCl = mass/molar mass = (32.0 g)/(58.45 g/mol) = (32.0 g NaCl)*(1 mol of NaCl)/(58.45 g NaCl) = 0.547 mol ≅ 0.55 mol.
B. What does Amanda need to do next to calculate the molarity of the NaCl solution? Show your work for full credit.
Molarity is the no. of moles of solute dissolved in a 1.0 liter of a solution.
∴ M = (no. of moles of NaCl)/(volume of solution (L)) = (0.55 mol)/(0.75 L) = 0.73 M.
Which half-reaction correctly represents reduction?
A) Ag -> Ag+ + e–
B) F2 -> 2 F– + 2e–
C) Au3+ + 3e– -> Au
D) Fe2+ + e– -> Fe3+
The half-reaction that is correctly represents reduction is Au₃⁺ + 3e– -> Au. The correct option is C.
What is half-reactions?
The half-reaction is an oxidation and reduction reaction of a redox reaction. It can be either oxidation or reduction. The half-reaction occurs due to change in oxidation state of a reactant.
An example is Zn Cu galvanic cell.
Thus, the correct option is C) Au3+ + 3e– -> Au.
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What is the molar mass of MgCl2? Report your answer to the nearest 0.1 g/mol.
Answer:
95.2 g/mol
Explanation:
To calculate the molar mass of MgCl2
We have to separately see the molar masses of Magnesium and Chlorine
Molar mass of Magnesium: 24.305 g/mol
Molar mass of Chlorine: 35.453 g/mol
As there are two atoms of chlorine in the said molecule so the molar mass of chlorine will be multiplied by 2.
35.453*2 = 70.906 g/mol
So the total molar mass of the said molecule = Molar mass of Mg + Molar mass of two atoms of chlorine
= 24.305 + 70.906
=95.211 g/mol
Rounding off to .1
95.2 g/mol
The molar mass of magnesium chloride (MgCl₂) is calculated by summing the molar mass of magnesium (24.31 g/mol) with twice the molar mass of chlorine (35.45 g/mol for each Cl), resulting in 95.21 g/mol.
The molar mass of magnesium chloride (MgCl₂) can be calculated by adding the molar masses of magnesium (Mg) and chlorine (Cl) in the compound. Magnesium has a molar mass of 24.31 g/mol, and since there are two chlorine atoms in MgCl₂, we must consider the molar mass of Cl (approximately 35.45 g/mol) twice.
Thus, the molar mass of MgCl₂ is calculated as:
24.31 g/mol (for Mg) + 2 * 35.45 g/mol (for Cl) = 95.21 g/mol.
Therefore, the molar mass of MgCl₂ is 95.21 g/mol, which we would report to the nearest 0.1 g/mol as required.
Can Sodium be used to distinguish between cyclobutanol and butanoic acid
Answer:
[tex]\boxed{\text{No}}[/tex]
Explanation:
Na reacts with all OH groups to produce hydrogen.
The reaction with cyclobutanol is shown below.
The reaction with butanoic acid is
[tex]\rm CH_{3}CH_{2}CH_{2}COOH\xrightarrow{\text{Na}} CH_{3}CH_{2}CH_{2}COO^{-} + H_{2}[/tex]
Both compounds release bubbles of hydrogen, so you can't use sodium to distinguish between them.
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When 0.5 g of powdered iron (III) oxide was added to 100 cm3 of hydrogen peroxide, water and oxygen were produced. Iron (III) oxide was not used up in the reaction. Based on the information, which of the following is likely to increase the rate formation of the products?
A. Replacing the powdered iron oxide with its cubical crystals
B. Using 150 cm3 of hydrogen peroxide
C. Removing iron oxide from the reaction mixture
D. Using 1.0 gram of iron oxide
Its B. Using 150 cm3 of hydrogen peroxide
The answer is B because when you calculate it you will get the same amount of hydrogen peroxide.
Good luck,!
What is the oxidation state of nitrogen in nano2
Answer:
Therefore, the oxidation state of N in NaNO₂ is +3
Explanation:
Problem: calculating the oxidation state of nitrogen N in NaNO₂
let us denote the oxidation number of Nitrogen as N:
We know from the periodic table that Na has an oxidation number of +1 i.e it will readily want to lose 1 electron so as to complete its octet.
Oxygen is known to have an oxidation number of -2
Summation of the oxidation number of each atoms is 0 for neutral compound.
Therefore to calculate the oxidation state of Nitrogen in NaNO₂, we express as:
+1 + N + (-2 x 2) = 0
1 + N = 4
N = 4-1 = +3
Therefore, the oxidation state of N in NaNO₂ is +3
If 89.6 joules of heat 20.0 grams of iron from 30.0 C to 40.0 C, what is the specific heat of the iron in J/g.C?
Answer:
H = m c ΔT
89.6 J = (20.0 g) × c × (40.0 - 30.0)°C
Specific heat of iron, c = 89.6 / [20.0 × (40.0 - 30.0)] J/(g°C) = 0.448 J/(g°C)
If 89.6 joules of heat 20.0 grams of iron from 30.0 C to 40.0 C, then the specific heat of the iron in J/g. degree C is 0.448 J/g. degree C.
How do we calculate the specific heat?The formula which we used to calculate the amount of specific heat of any substance involved in a chemical reaction is:
Q = mcΔT, where
Q = absorbed heat = 89.6 Jm = mass = 20gc = specific heat = ?ΔT = change in temperature = 40 - 30 = 10 degree COn putting all these values, we get
c = 89.6 / (20)(10) = 0.448 J/g. degree C
Hence, 0.448 J/g. degree C is the specific heat of iron.
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In an acid-base neutralization reaction 38.74 ml of 0.500 m potassium hydroxide reacts with 50.00 ml of sulfuric acid solution. What is the concentration of the h2so4 solution?
Answer:
0.2 M.
Explanation:
For the acid-base neutralization, we have the role:The no. of millimoles of acid is equal to that of the base at the neutralization.
∴ (XMV) KOH = (XMV) H₂SO₄.
X is the no. of reproducible H⁺ (for acid) or OH⁻ (for base),
M is the molarity.
V is the volume.
For KOH:X = 1, M = 0.5 M, V = 38.74 mL.
For H₂SO₄:X = 2, M = ??? M, V = 50.0 mL.
∴ M of H₂SO₄ = (XMV) KOH/(XV) H₂SO₄ = (1)(0.5 M)(38.74 mL)/(2)(50.0 mL) = 0.1937 M ≅ 0.2 M.
The concentration of the sulfuric acid (H2SO4) in the solution is 0.1937 M, as calculated by using the balanced chemical equation for the reaction, the stoichiometric ratio of the reactants, and the principle of molarity.
Explanation:The student is asking about an acid-base neutralization reaction involving a known volume and concentration of potassium hydroxide reacting with a known volume but an unknown concentration of sulfuric acid. The goal is to calculate the concentration of the sulfuric acid.
To answer this, we first need to know that the balanced chemical equation for this reaction is: H2SO4 + 2KOH -> K2SO4 + 2H2O. According to this stoichiometry, it takes one molecule of sulfuric acid to neutralize two molecules of potassium hydroxide. Therefore, the moles of potassium hydroxide is 0.01937 mol (calculated by volume (in liters) multiplied by molarity).
Based on the stoichiometric ratio, the required moles of sulfuric acid to the given moles of potassium hydroxide is 0.009685 mol. We can then calculate the concentration of H2SO4 by dividing this value by its volume (in liters): 0.009685 mol / 0.05 L = 0.1937 M.
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Jeff used an equal arm balance to weigh a 4.312 g sample of sodium chloride. Which of these measurements made by Jeff is the most accurate? (5 points) 4.5 g 4.1 g 4.2 g 4.3 g
Answer:
4.3.
Explanation:
Measurements that are close to the known value are said to be accurate, whereas measurements that are close to each other are said to be precise.The most closest measurement to the known value is 4.3 g.So, the right choice is: 4.3 g.Answer: The most accurate measurement made by Jeff is 4.3 g
Explanation:
Accuracy is defined as the closeness of a measured value to a standard or known value.
For Example: If the mass of a substance is 58 kg and one person weighed 57 kg and another person weighed 60 kg. Then, the weight measured by first person is more accurate.
We are given:
Mass of the sample = 4.312 g
So, the measurement close to 4.312 grams will be the accurate value.
Hence, the most accurate measurement made by Jeff is 4.3 g
How much heat is released when 105 g of steam at 100.0°C is cooled to ice at -15.0°C? The enthalpy of vaporization of water is 40.67 kJ/mol, the enthalpy of fusion for water is 6.01 kJ/mol, the molar heat capacity of liquid water is 75.4 J/(mol • °C), and the molar heat capacity of ice is 36.4 J/(mol • °C).
Final answer:
To determine the amount of heat released when cooling 105 g of steam at 100.0°C to ice at -15.0°C, we calculate the heat released during condensation, cooling of water, freezing, and further cooling of ice to the final temperature, totaling 319.4 kJ of heat released.
Explanation:
To calculate the total heat released when 105 g of steam at 100.0°C is cooled to ice at -15.0°C, we will break down the process into several steps and calculate the heat change for each step. The molecular weight of water (H2O) is approximately 18 g/mol, so the number of moles of water in 105 g is 105 g / 18 g/mol = 5.83 mol.
First, steam is condensed to liquid water at 100.0°C. The heat released is calculated using the enthalpy of vaporization: Heat = number of moles × enthalpy of vaporization = 5.83 mol × 40.67 kJ/mol = 237.3 kJ.Next, the liquid water is cooled from 100.0°C to 0°C. The heat released is: Heat = number of moles × heat capacity of liquid water × temperature change = 5.83 mol × 75.4 J/mol°C × 100°C = 43.9 kJ.Then, the liquid water is frozen at 0°C. The heat released during freezing is: Heat = number of moles × enthalpy of fusion = 5.83 mol × 6.01 kJ/mol = 35.0 kJ.Finally, the ice is cooled from 0°C to -15.0°C. The heat released is: Heat = number of moles × heat capacity of ice × temperature change = 5.83 mol × 36.4 J/mol°C × 15°C = 3.2 kJ.The total heat released during the whole process is the sum of heat released in each step: 237.3 kJ + 43.9 kJ + 35.0 kJ + 3.2 kJ = 319.4 kJ.
What is required for a chemical reaction to occur?
Answer:
In order to a chemical reaction to occur it is necessary that the reactants collide with enough energy and with the right orientation.Explanation:
The conditions for a chemical reaction to occur are explained by the collision theory.
The collision must provide enough energy to overcome the energy barrier called activation energy.
If the energy of the collision is less than the activation energy then the bonds of the reactants will not be broken and the reactants will not be transformed into other substances (products).
Also, to brake the bonds of the reactants and form the new ones of the transition state (intermediate compound known as activated complex), it is needed that the atoms of one molecule hit the right atoms of the other molecule, this is the collision must have the appropriate orientation to yield the products.
What is the place of metalloids in the periodic table?
Which compound is bonded covalently? A.KF B.MgS C.BeO D.SO2
Answer:
SO2 is bonded covalently
Explanation:
Atoms that share electrons in a chemical bond have covalent bonds.
Which statement best describes the electronegativity of an element?
A.
Electronegativity of an atom is its ability to lose electrons during cation formation.
B.
Electronegativity of an atom is its ability to share electrons during a covalent bond formation.
C.
Electronegativity of an atom is its ability to gain electrons during anion formation.
D.
Electronegativity of an atom is its ability to produce energy while losing an electron.
E.
Electronegativity of an atom is its ability to attract electrons during bond formation.
Answer: The correct answer is Option E.
Explanation:
Electronegativity is the chemical property of an element. This is defined as the tendency of an atom to attract the shared pair of electrons towards itself when a bond is formed.
This property of an atom increases as we move from left to right in a period because the number of charge on the nucleus increases.
But this property decreases as we move from top to bottom in a group because electrons get added up in the new shells which make it further far away from the nucleus.
Thus, the correct answer is Option E.
Polonium (Po) decays by alpha emission. What will be the mass number of the new atom produced by the alpha decay of Po?
The mass number of the new atom produced by the alpha decay of Polonium (Po) will decrease by 4, as an alpha particle (consisting of 2 protons and 2 neutrons) is emitted.
Explanation:The mass number of a new atom produced by the alpha decay of Polonium (Po) will be reduced by 4. This is because during alpha decay, an atom emits an alpha particle, which consists of 2 protons and 2 neutrons, equivalent to a helium-4 nucleus. Therefore, the subtraction of these particles from the parent atom result in a decrease in the mass number by 4.
For example, if we consider Polonium-209 undergoing alpha decay, we use the subtraction method (209 - 4 = 205) to determine the mass number of the resulting atom, which in this case would be Lead-205 (Pb-205). This is consistent with the general pattern observed in radioactive decay of heavy nuclei.
Can y’all help me solve these three questions on my review packet?
Answer:
12.
Infrared has the lower frequency while visible light has a higher frequency.
13.
As = 33
1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p³
K = 19
1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹
Sr = 38
1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s²
Kr = 36
1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶
14. SEE ATTACHED PICTURE
Explanation:
12. The relationship between wavelength and frequency can be seen in the equations:
[tex]F=\dfrac{c}{\lambda}[/tex] and [tex]\lambda=\dfrac{c}{F}[/tex]
Where:
λ = wavelength
F = frequency
c = constant (speed of light)
As you can see that they are indirectly proportional. So as the frequency increases, the wavelength decreases and vis-a-vis.
13. Electronic configuration of an element can be determined using the pattern attached. It determines the electronic structure of an atom. Remember:
s subshell holds 2 electrons
p subshell holds 6 electrons
d subshell holds 10 electrons
f subshell holds 14 electrons
You know when to stop when the number of electrons sum up to the atomic number (which is the number of protons) in a stable atom.
As = 33
1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p³ (Stop here because the electrons sum up to 33)
K = 19
1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹
Sr = 38
1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s²
Kr = 36
1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶
14. Lewis Dot symbol represents how many valence electrons an atom has. You can determine the Lewis Dot Structure also based on the electronic configuration of the element by adding up the number of electrons there are in the highest energy level. The energy level is indicated by the numerical coefficient.
S = 16
1s² 2s² 2p⁶ 3s² 3p⁴
Notice that the highest energy level that appears here is 3, so add up the number of electrons.
2 + 4 = 6 (This is how many valence electrons Sulfur (S) has.)
So we draw the symbol of Sulfur and put three dots around it.
C = 6
1s² 2s² 2p²
2 + 2 = 4
Sr = 38
1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s²
2 valence electrons (Because there are only 2 electrons in the 5th energy level)
*Fe = 26
1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁶
2 valence electrons (Because there are only 2 electrons in the 4th energy level)
Al = 13 1s² 2s² 2p⁶ 3s² 3p¹
2 + 1 = 3
*Note: Fe or Iron is a transition metal. Technically, 3d in this case is a higher energy level. However, when it comes to Lewis dot structure, d and f shells that are not filled are usually omitted, so it will follow the 4s. Generally when putting dots around we follow the sequence of the X element shown in the attached file.