Answer:
D. 0.60 L.
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) NaOH = (XMV) H₂SO₄.
X is the no. of reproducible H⁺ (for acid) or OH⁻ (for base),
M is the molarity.
V is the volume.
For NaOH:X = 1, M = 4.0 M, V = ??? L.
For H₂SO₄:X = 2, M = 4.0 M, V = 0.3 L.
∴ V of NaOH = (XMV) H₂SO₄/(XM) NaOH = (2)(4.0 M)(0.3 L)/(1)(4.0 M) = 0.6 L.
So, the right choice is: D. 0.60 L.
What is the physical state of the smallest alkanes at room temperature?
They are gases at room temperature
Hope this helps:)
The smallest alkanes, which are those with one to four carbon atoms, are gases at room temperature due to their nonpolar nature and weak dispersion forces.
The physical state of the smallest alkanes at room temperature can be understood by analyzing their properties and boiling points. Alkanes are nonpolar molecules associated through weak dispersion forces. The boiling point of a substance is a rough measure of the energy needed to separate molecules from each other. In the case of the smallest alkanes, specifically those with one to four carbon atoms, they are gases at room temperature. Example alkanes that are gases at room temperature include methane (CH4), ethane (C2H6), propane (C3H8), and butane (C4H10). In contrast, the physical state changes as the number of carbons increases; alkanes become liquids and eventually solids as the carbon chain length and molecular weight increase.
1+1is= Make that as a ?
Answer: The correct answer to this problem is 2.
Explanation:
We are given a mathematical problem, which is:
1 + 1 = ?
To solve this, we use the mathematical operator known as addition. In this, we add two numbers and the resulting value is the answer to the problem.
By adding 1 and 1, we get:
[tex]\Rightarrow 1+1=2[/tex]
Thus, the correct answer to this problem is 2.
Compound MN decomposes to form M and N in a reaction that is first-order with respect to MN and first order overall. The half-life for the reaction is 2.3 × 10^4 s. What is the rate constant of this reaction at 25°C? MN → M + N a) 3.0 × 10^3 s
b) 1.6 × 10^(–4) s^(–1)
c) 3.0 × 10^(–5) s^(–1)
d) 3.3 × 10^(–4) s^(–1)
Answer:
Option c) 3.0 × 10 ⁻⁵ s⁻¹Explanation:
The reaction given follows this pattern:
1) Decomposition reaction:
MN → M + N2) First-order kinetic with respect to MN and first-order overall:
Rate: r = - d{MN]/ dt = k [MN]Integration: -d[MN] / [MN] = kdtSolution:
[tex]ln\frac{[MN]}{[MN]_0}=-kt[/tex]
Half-life time: [MN]/[MN]o= 1/2t = τ
∴ τ = ln(2) / k ⇒ k = ln (2) / τ = ln(2) / 2.3 × 10⁴ s / ln(2) = 3.0 × 10⁻⁵ s⁻¹
The rate constant for a first-order reaction can be calculated using the half-life of the reaction. In this case, the rate constant for the given reaction at 25°C is 3.0 × 10⁻⁵ s⁻¹.So,option c is correct.
The rate law for a first-order reaction is given by: Rate = k[reactant]
The half-life of a first-order reaction can be calculated using the formula: t1/2 = 0.693 / k
Given that the half-life of the reaction is 2.3 × 10⁴s and it is first order overall, the rate constant can be calculated as k = 0.693 /[tex]t_{ 1/2}[/tex] = 0.693 / 2.3 × 10⁴ = 3.0 × 10⁻⁵ s⁻¹.
What needs to be done to balance this equation
Do you nothing (equation is balanced)
Change O2 to O4 on the left side of the equation
Add coefficient 2 to O2 on the left side of the equation
Remove Coefficient in front of H2O on the right side of the equation
Answer : The correct option is, Add coefficient 2 to [tex]O_2[/tex] on the left side of the equation.
Explanation :
Balanced chemical reaction : It is defined as the reaction in which the number of atoms of individual elements present on reactant side must be equal to the product side.
The reactants and the products are separated by right arrow.
The species present on the left side of the right arrow is known as reactant and the species present on the right side of the right arrow is known as product.
If the amount of atoms of each type on the left and right sides of a reaction differs then to balance the equation by adding coefficient in the front of the elements or molecule or compound in the chemical equation.
The coefficient tell us about that how many molecules or atoms present in the chemical equation.
The given chemical reaction is,
[tex]CH_4+O_2\rightarrow CO_2+2H_2O[/tex]
This reaction is an unbalanced chemical reaction because in this reaction number of oxygen atoms are not balanced.
In order to balance the chemical equation, the coefficient '2' put before the [tex]O_2[/tex] and we get the balanced chemical equation.
The balanced chemical reaction will be,
[tex]CH_4+2O_2\rightarrow CO_2+2H_2O[/tex]
Hence, the correct option is, Add coefficient 2 to [tex]O_2[/tex] on the left side of the equation.
What condition must be satisfied by a balanced chemical equation?
Answer:
The chemical equation needs to be balanced so that it follows the law of conservation of mass. A balanced chemical equation occurs when the number of the different atoms of elements in the reactants side is equal to that of the products side. Balancing chemical equations is a process of trial and error.
Explanation:
Arrange these elements according to electronegativity. Rb F Al N Na
Answer:
Rb, Na, Al, N, F
Explanation:
Rb has an EN of 0.8, Na with 0.9 EN, Al with 1.5 EN, N with 3.0 EN, and F with 4.0 EN.
The elements Rb, F, Al, N, and Na are arranged in order of increasing electronegativity as Rb < Na < Al < N < F. Fluorine is the most electronegative while Rubidium is the least.
Explanation:Electronegativity is a measure of the ability of an atom to attract electrons. In general, electronegativity increases from left to right across a period and decreases down a group in the periodic table. Based on this trend, the elements Rb, F, Al, N, and Na can be arranged in order of increasing electronegativity as follows: Rb < Na < Al < N < F. It's important to note that Fluorine (F) is the most electronegative element on the periodic table, followed by Nitrogen (N). Al (Aluminum), Na (Sodium), and Rb (Rubidium) are less electronegative as you go from right to left and down the periodic table.
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The elements Rb, F, Al, N, and Na are arranged in order of increasing electronegativity as Rb < Na < Al < N < F. Fluorine is the most electronegative while Rubidium is the least.
Explanation:Electronegativity is a measure of the ability of an atom to attract electrons. In general, electronegativity increases from left to right across a period and decreases down a group in the periodic table. Based on this trend, the elements Rb, F, Al, N, and Na can be arranged in order of increasing electronegativity as follows: Rb < Na < Al < N < F. It's important to note that Fluorine (F) is the most electronegative element on the periodic table, followed by Nitrogen (N). Al (Aluminum), Na (Sodium), and Rb (Rubidium) are less electronegative as you go from right to left and down the periodic table.
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a geologist concludes that a rock sample is an extrusive igneous rock. Based on this information, which statement about the rock is accurate?....please help me
Answer: The rock formed from cooling lava.
Explanation:Extrusive igneous rocks, also known as volcanic rocks, are formed at the crust's surface as a result of the partial melting of rocks within the mantle and crust.
A geologist concludes that a rock sample is an extrusive igneous rock.The rock formed from cooling lava is accurate.
What is Rock?A rock is a natural substance composed of solid crystals of different minerals that have been fused together into a solid lump. The minerals may or may not have been formed at the same timeThere are three kinds of rock: igneous, sedimentary, and metamorphic.A geologist concludes that a rock sample is an extrusive igneous rock.The rock formed from cooling lava is accurate.
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December 21 is the first day of winter in the northern hemisphere. What season is it in the southern hemisphere? A. Beginning of winter B. Beginning of spring C. Beginning of summer D. Beginning of autumn (fall)
Summer because the seasons in the Southern Hemisphere is the opposite of the seasons in the northern hemisphere.
1. For most of the 17 years in which he was active, the identity of the Unabomber remained a mystery.
True False
2. Polygraph machines measure physical changes in the body when the individual is asked 'yes' and 'no' questions.
True
False
3.False positives occur when the examinee tells the truth but his response is recorded as a lie.
True
False
Answer they are all true.
Explanation:
The Unabomber had no identity until he finally confessed in 1998. Therefore, the answer is true, (its almost like a trick question.)
The Polygraph machine does measure physical changes in the body, so the answer is true.
False positives are when the examinee tells a truth but it is recorded as a lie.
Which formula can be used to calculate the actual yield?
(Percent yield × theoretical yield) ÷ 100
(Percent yield ÷ theoretical yield) × 100
(Theoretical yield ÷ percent yield) × 100
(Theoretical yield × amount of reactants) ÷ 100
Answer:
(Percent yield × theoretical yield) ÷ 100.
Explanation:
∵ percent yield of the reaction = [(actual yield)/(theoretical yield)] x 100.
∴ actual yield = [(percent yield of the reaction) x (theoretical yield)]/100.
So the right choice is: (Percent yield × theoretical yield) ÷ 100 .
Answer : The correct option is, [tex]\frac{(\text{Percent yield}\times \text{Theoretical yield})}{100}[/tex]
Explanation :
The formula used for the percent yield will be :
[tex]\text{Percent yield}=\frac{\text{Actual yield}}{\text{Theoretical yield}}\times 100[/tex]
or,
[tex]\text{Actual yield}=\frac{(\text{Percent yield}\times \text{Theoretical yield})}{100}[/tex]
For example : If we are given that the percentage yield of a sample is 94.92% and the theoretical yield is 83.475 g. Now calculate the actual yield of the sample.
By using formula we get the value of actual yield.
[tex]\text{Actual yield}=\frac{(94.92\times 83.475)}{100}=79.23g[/tex]
Thus, the actual yield is, 79.23 g.
Hence, the formula used to calculate the actual yield can be, [tex]\frac{(\text{Percent yield}\times \text{Theoretical yield})}{100}[/tex]
how many grams are in 2.3 x10-4 moles of calcium phosphate ca3(po3)2
Final answer:
To find the number of grams in 2.3 x 10-4 moles of calcium phosphate (Ca3(PO4)2), you need to calculate the molar mass of calcium phosphate and then convert moles to grams.
Explanation:
To find the number of grams in 2.3 x 10-4 moles of calcium phosphate (Ca3(PO4)2), we need to calculate the molar mass of calcium phosphate and then convert moles to grams.
The molar mass of Ca3(PO4)2 can be calculated by adding the atomic masses of calcium (Ca), phosphorus (P), and oxygen (O). The atomic masses are: Ca = 40.078 g/mol, P = 30.973761 g/mol, O = 15.9994 g/mol.
Calculating the molar mass:
3Ca: (3 atoms) (40.078 g/mol/atom) = 120.234 g/mol2P: (2 atoms) (30.973761 g/mol/atom) = 61.947522 g/mol8O: (8 atoms) (15.9994 g/mol/atom) = 127.9952 g/molTotal molar mass of Ca3(PO4)2 = 120.234 g/mol + 61.947522 g/mol + 127.9952 g/mol = 310.176722 g/mol.
Now, we can use the equation:
mass(g) = moles x molar mass(g/mol)
Substituting the given values:
mass(g) = 2.3 x 10-4 moles x 310.176722 g/mol
Calculating the result:
mass(g) = 0.0712 g
Therefore, there are 0.0712 grams in 2.3 x 10-4 moles of calcium phosphate (Ca3(PO4)2).
Which formula equation shows a reversible reaction? a. 2Na+F2–> 2NaF b. CaCO3–> CaO+CO2 c. NH4CI(s)—–NH3(g.+HCI(g. 2H2O2(aq)–pt—> 2H2O(I)+O2(g.?
Answer:
The choice c. NH₄CI(s) ⇄ NH₃(g) + HCI(g) is the reversible reaction.Explanation:
The formula equations given are:
a. 2Na + F₂ → 2NaF b. CaCO₃ → CaO + CO₂ c. NH₄CI(s) ⇄ NH₃(g) + HCI(g)d. 2H₂O₂(aq) → 2H₂O(I)+O₂(g)
[there is also a Pt symbol over the arrow, which means that Pt
is a catalyst]
Reversible reactions are reactions that may happen in both directions, i.e. there is a direct or forward reaction and a reverse reaction.
The symbol used to show a reversible reaction is the double arrow (⇄).
The double arrow shows tha both left side substances and right side substances are reactants and products.
In the reaction NH₄CI(s) ⇄ NH₃(g) + HCI(g) you have:
NH₄CI(s) → NH₃(g) + HCI(g) is the direct reaction. In this, NH₄CI(s) is the reactant and NH₃(g) + HCI(g) are the products.NH₄CI(s) ← NH₃(g) + HCI(g) (notice the arrow goes from right to left) is the reverse reaction. In this, NH₄CI(s) is the product and both NH₃(g) and HCI(g) are the reactants.All the other equations are written with a single arrow, so they are not reversible reactions.
Answer:
just did edge test, got 100%:
C. NH4Cl(s)<-->NH3(g) + HCl(g)
During an experiment, 104 grams of calcium carbonate reacted with an excess amount of hydrochloric acid. If the percent yield of the reaction was 80.15%, what was the actual amount of calcium chloride formed? CaCO3 + HCl → CaCl2 + CO2 + H2O 90.1 grams 92.4 grams 109.2 grams 115.3 grams
Answer:
92.4 grams.
Explanation:
From the balanced reaction:CaCO₃ + 2HCl → CaCl₂ + CO₂ + H₂O,
1.0 mole of CaCO₃ reacts with 2.0 moles of HCl to produce 1.0 mole of CaCl₂, 1.0 mole of CO₂, and 1.0 mole of H₂O.
We need to calculate the no. of moles of (104 g) of CaCO₃:no. of moles of CaCO₃ = mass/molar mass = (104 g)/(100.08 g/mol) = 1.039 mol.
Using cross multiplication:
1.0 mole of CaCO₃ produce → 1.0 mole of CaCl₂.
∴ 1.039 mole of CaCO₃ produce → 1.039 mole of CaCl₂.
∴ The amount of CaCl₂ produced = no. of moles x molar mass = (1.039 mol)(110.98 g/mol) = 114.3 g.
∵ percent yield of the reaction = [(actual yield)/(theoretical yield)] x 100.
Percent yield of the reaction = 80.15%, theoretical yield = 115.3 g.
∴ actual yield = [(percent yield of the reaction)(theoretical yield)]/100 = [(80.15%)/(115.3 g)] / 100 = 92.42 g ≅ 92.4 g.
The reaction 3o2 -> 2o3 has a rate of change of o2 concentation equal to -0.90 mol/l*s. what is the rate of change of o3 concentration
Answer:
0.6 mol/L.s.
Explanation:
For the reaction:3O₂ → 2O₃,
the rate of the reaction = - 1/3d[O₂]/dt = 1/2d[O₃]/dt
where, d[O₂]/dt is the rate of change of O₂ concentation = - 0.9 mol/L.s.
d[O₃]/dt is the rate of change of O₃ concentration.
∴ d[O₃]/dt = - 2/3(d[O₂]/dt) = - 2/3(- 0.9 mol/L.s) = 0.6 mol/L.s.
What is the function of the cell membrane? (4 points) To add structure and support to the shape of the cell To control what substances enter and leave the cell To monitor the amount of glucose needed by the cell To prevent waste from entering and leaving the cell
Answer:
To control what substances enter and leave the cell
Explanation:
The cell membrane controls the movement of substances in and out of cells and organelles. In this way, it is selectively permeable to ions and organic molecules.
Answer:
To control what substances enter and leave the cell
Explanation:
Select true or false: if the ph of pure water is 7.0, the hydroxide ion concentration in pure water is 1 × 10–7 m.
Answer:
True
Explanation:
as the ph of pure water is 7
(-)log(10^-7) = 7
The statement if the pH of pure water is 7.0, the hydroxide ion concentration in pure water is 1 × 10⁻⁷M is true.
How do we calculate the hydroxide ion concentration?Hydroxide ion concentration in the solution will be calculated by using the below equation as:
pOH = -log[OH⁻]
Relation between pH and pOH is :
pH + pOH = 14
Given that, pH = 7
So, pOH = 14 - 7 = 7
By using first equation, we have
7 = -log[OH⁻]
[OH⁻] = 10⁻⁷M
Hence, hydroxide ion concentration in pure water is 1×10⁻⁷M.
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A gas occupies a volume of 2.4 L at 14.1 kPa. What volume will the gas occupy at 84.6 kPa?
Answer:
0.40 LExplanation:
Boyle's law for gases states that, at constant temperature, the volume and pressure of a fixed amount of gas are inversely related.
Mathematically, that is:
PV = constantP₁V₁ = P₂V₂Here, you have:
V₁ = 2.4 LP₁ = 14.1 KpaP₂ = 84.6 KPaV₂ = ?Then, you can solve for V₂:
V₂ = P₁V₁ / P₂Substitute and compute:
V₂ = 14.1 KPa × 2.4L / 84.6 KPa = 0.40 L ← answerAnswer:
0.40 L
Explanation:
DOUBLE POINTS!!Please help ASAP!! 1 hour left !!
Explain the difference between temperature and heat. Also, state what determines the direction of heat transfer.
Everything helps !! Thanks in advance!! Giving brainliest!!
Temperature is a measurement of heat whereas heat is just an energy.
With that being said the heat is moving from hot to cold.
Answer:
Explanation:
So let's define both of these . these are two different things
Temperature : it's average kinetic energy of the particles within the system .
So if I increase the motion of particles ,the temperature will increase . If I decrease the motion of particles ,the temperature will decrease
Heat : it is the flow of energy due to temperature difference .
If I have a metal strip and I heat one side of it and the other side is cold then due to temperature difference ,heat will flow from the heated part of the metal strip to cold part of the strip.
------------------
Heat only provides a direction of the flow of heat while temperature is just the average kinetic energy of the substance ( it has no direction .BUT here are some more differences :
Heat is measured by a device called caloriometer
Temperature is measured by Thermometer
Unit of heat : joules
Unit if temperature : Kelvin
What type of compound is always an electrolyte? A. Nonpolar covalent B. Polar covalent C. Network solid D. Ionic
The answer is d ionic
HELP ASAP PLEASE!!!
Formulas for acids usually begin with one or more _____ ions.
hydrogen ions
H2SO4
HNO3
H3PO4
etc
How is an isotope different from the standard form of a chemical element?
Answer:
The standard form of a chemical element is the natural mixture of several isotopes of the same element, which is atoms with the same number of protons but different number of neutrons, while an isotope is a particular kind of atom with a definite number of neutrons.Explanation:
A chemical element is a pure substance formed by atoms with the same atomic number (number of protons). This is because it is the number of protons what identifies an element.
For example: oxygen is a chemical element, so oxygen is formed by only atoms of oxygen, and the atomic number of those atoms is 8, because every oxygen atom has 8 protons.
Nevertheless, some atoms of oxygen, may have different number of neutrons. Isotopes are different kind of atoms of the same element, which only differ in the number of neutrons. So, some atoms of oxygen will have 8 neutrons, other 9 neutrons, and other 10 neutrons (those are the stable isotopes of oxygen).
That difference in neutrons, is generally accepted that, does not modifiy substantially the chemical properties of the element, but the mass number. So, the isotopes with more neutrons wil be heavier, and the isotopes with less neutrons will be lighter.
Mass number = number of protons + number of neutrons.In general a chemical element is formed by a mixutre of isotopes of the same element.
Answer:
its B :diffrent number of neutrons
Explanation:
Metals and nonmetals can react with each other to form ions. Complete these statements.A potassium atom gains or loses (electrons/protons/neutrons) and forms how many ion?A sulfur atom gains or loses (electrons/protons/neutrons) and forms how many ion?
A potassium atom loses one electron to form a potassium ion with a +1 charge, while a sulfur atom gains two electrons to form a sulfide ion with a -2 charge.
Explanation:Metals and nonmetals can react with each other to form ions through the transfer of electrons. When a potassium atom reacts, it loses one electron and forms a potassium ion with a +1 charge (K+). Potassium is an alkali metal and it typically loses one electron to achieve a noble gas electron configuration.
On the other hand, a sulfur atom typically gains two electrons to form a sulfide ion with a -2 charge (S2-). As a nonmetal, sulfur gains electrons to achieve an octet, resembling the electron configuration of a noble gas.
[GT.02]Which of these forces in carbon-14 isotopes transforms a neutron into a proton?gravitational forceselectromagnetic forcesweak nuclear forcesstrong nuclear forces
Answer:
The weak nuclear force.
Explanation:
This force is active in radioactivity.
Which gas law is considered when scuba diving?
Ideal gas law
Charles law
Boyles law
Combined gas law
The law is Boyel's law.
Explanation:One of the primary laws of material science that impacts the submerged jumping condition for scuba jumpers is Boyle's law.
The law states that as weight changes, the volume of gases in a jumper's body pits and adaptable gear changes as well. Where the water weight builds, 'air spaces' reduces in size, yet as water weight diminishes, the 'air spaces' increments in size. Where the two changes are in direct extent to the weight increment or lessening, the temperature is held consistent.
Recently you viewed a movie in which a spaceship blows up outside a space station. The people inside the space station jump with surprise upon hearing the explosion. What is wrong with this scenario? Sound is a transverse wave. Sound needs a medium through which to travel. Sound is a longitudinal wave. There are no such things as space stations. NEXT
Answer:
Sound needs a medium through which to travel.
Explanation:
In space there is no air or medium. Sound waves need medium to travel. It cannot travel through vacuum. Sounds waves are mechanical waves unlike electromagnetic waves. Electromagnetic waves can travel through vacuum. But mechanical waves such as sound waves needs a medium to propagate the energy. So it is very unlikely that people inside the space station can hear the explosion that occurs in space outside the space station.
1.A sample of pure calcium fluoride with a mass of 15.0 g contains 7.70 g of calcium. How much calcium is contained in 40.0 g of calcium fluoride? 2.Silver has two isotopes. One isotope contains 60 neutrons and has a percent abundance of 51.839% the other contains 62 neutrons. Give the atomic symbols for the two isotopes.3.What is the average atomic weight of silver? What is the mass (in grams) of a single chlorine molecule? 4.How many moles of ethanol (CH_3CH_2OH) are in 141 mg?
These are five questions and five answers.
1) Question 1. A sample of pure calcium fluoride with a mass of 15.0 g contains 7.70 g of calcium. How much calcium is contained in 40.0 g of calcium fluoride?
Answer:
20.5 g CaExplanation:
Calcium fluoride being a pure substance, has a fixed chemical compositon, which means that their elements (atoms), in any sample, are always in the same proportion.
Then, you can set the followoing proportion:
7.70 g Ca / 15.0 g CaF₂ = x / 40.0 g CaF₂Now, solve for x:
x = 40.0 g CaF₂ × 7.70 g Ca / 15.0 g CaF₂ = 20.5 g Ca.The answer must be expressed with 3 significan figures, since the three data are given with 3 significan figures.
2) Question 2. Silver has two isotopes. One isotope contains 60 neutrons and has a percent abundance of 51.839% the other contains 62 neutrons. Give the atomic symbols for the two isotopes.
Answer:
Isotope that contains 60 neutrons: ¹⁰⁷₄₇AgIsotope that contains 62 neutrons: ¹⁰⁹₄₇AgExplanation:
Isotopes are atoms of the same element, with different number of neutrons, so all the isotopes of an element have the same atomic number, Z (number of protons) and different mass number A (number of neutrons + protons).The atomic symbols for isotopes uses the chemical symbol of the atom (Ag for silver); a subscript to the left of the chemical symbol that represents the atomic mass (47 for silver); and a superscript to the left of the chemical symbol that represents the mass number.The mass number, A, for each silver isotope is calculated in this way:
Isotope that contains 60 neutrons: A = 60 + 47 = 107
Isotope that contains 62 neutrons: A = 62 + 47 = 109
Then, the respective atomic symboles are:Isotope with 60 neutrons: ¹⁰⁷₄₇Ag
Isotope with 62 neutrons: ¹⁰⁹₄₇Ag
3) Question 3. What is the average atomic weight of silver? What is the mass (in grams) of a single chlorine molecule?
Answer:
107.96 amuExplanation:
The atomic wieght of the elements is the weighted average weight of the different isotopes of the same element found in the nature, taking into account their relative abundance.
Average atomic weight = ∑( abundance × individual atomic weight)
Average atomic weight of silver = (abundace of isotope 1 × atomic weight isotope 1) + (abundance isotope 2 × atomic weight isotope 2)Abundance isotope 1 = 51.839%Atomic weight isotope 1 = mass number = 60 neutrons + 47 protons = 107 a.m.uAbundance isotope 2 = 100% - 51.839% = 48.161%Atomic weight isotope 2 = 62 neutrons + 47 protons = 109 a.m.u.Average atomic weight of silve = 107 amu × 51.839% + 109 amu × 48.161% = 107.96 amu4) Question without number: What is the mass (in grams) of a single chlorine molecule
Answer:
1.177 × 10⁻²² gExplanation:
The chlorine molecule is diatomic. That means that each molecule contains two atoms. The chemical formula of chlorine molecule is Cl₂.
The mass of one mole of molecules of Cl₂ is 2 × 35.453 g/mol = 70.906 g/mol
Mass of a single molecule = mass of one mol / number of molecules in one molMass of a single molecule = 70.906 g/mol / (6.022 × 10²³ molecules / mol)Mass of a single molecule = 11.77 × 10⁻²³ g = 1.177 × 10⁻²² g5) Question 4. How many moles of ethanol (CH₃CH₂OH) are in 141 mg?
Answer:
0.00301 molExplanation:
Molar mass of CH₃CH₂OH = 2 × 12.011 g/mol + 6 × 1.008 g/mol + 15.999 g/mol = 46.069 g/mol.Formula: number of moles = mass in grams / molar massCalculation: number of moles = 141 mg × ( 1 g /1000 mg) / (46.069 g/mol = 0.00301 molIn 40.0 g of calcium fluoride, there is 20.53 g of calcium. Silver has two isotopes represented by Ag-107 and Ag-109, with the average atomic weight of silver calculated by using their percent abundances. For ethanol, 141 mg corresponds to 0.00306 moles.
Calcium is contained in 40.0 g of calcium fluoride (CaF₂), we use a proportional relationship based on the information provided:
15.0 g of CaF₂ contains 7.70 g of calcium.
40.0 g of CaF₂ contains X g of calcium.
By setting up a proportion, we solve for X:
(7.70 g Ca / 15.0 g CaF₂) = (X g Ca / 40.0 g CaF₂)X = (7.70 g Ca / 15.0 g CaF₂)
40.0 g CaF₂)
X = 20.53 g of calcium.
The atomic symbols for the two isotopes of silver are: Ag-107 (47 protons + 60 neutrons) and Ag-109 (47 protons + 62 neutrons).
The average atomic weight of silver is calculated considering the weighted average of these isotopes and their percent abundances. The mass of a single chlorine molecule (Cl₂), not a chlorine atom, would be the sum of the atomic masses of the two chlorine atoms. However, the specific mass for a single molecule of Cl₂ in grams is a very small number, given that it's typically calculated in atomic mass units.
Finding the number of moles of ethanol (CH₃CH₂OH) in 141 mg:
The molar mass of ethanol is approximately 46.07 g/mol. Therefore:(141 mg) (Unit conversion from mg to g: 141 mg * (1 g/ 1000 mg)) (Divide by the molar mass of ethanol: (0.141 g) / 46.07 g/mol) = 0.00306 mol of ethanol.
Solve using the correct gas law formula: If the pressure exerted by gas at 25 °C in a constant volume of 3.81 atm, What will the pressure be at 50 °C?
Answer:
4.31 atm.
Explanation:
We can use the general law of ideal gas: PV = nRT.where, P is the pressure of the gas in atm.
V is the volume of the gas in L.
n is the no. of moles of the gas in mol.
R is the general gas constant,
T is the temperature of the gas in K.
If n and V are constant, and have different values of P and T:(P₁T₂) = (P₂T₁)
Knowing that:
P₁ = 3.81 atm, T₁ = 25°C + 273 = 298 K,
P₂ = ??? atm, T₂ = 50°C + 273 = 323 K,
Applying in the above equation(P₁T₂) = (P₂T₁)
∴ P₂ = (P₁T₂)/(T₁) = (3.81 atm)(323 K)/(298 K) = 4.31 atm.
When a 3.22 g sample of an unknown hydrate of sodium sulfate, Na2SO4 . X H2O (s), is heated, H2O (molar mass 18 g) is driven off. The mass of the anhydrous Na2SO4 (s) (molar mass 142 g) that remains is 1.42g. the value of X in the hydrate is
Answer:
[tex]\boxed{x = 10}[/tex]
Explanation:
This is like an empirical formula question, except that you are finding the molar ratio of compounds instead of atoms.
Step 1. Gather the information in one place.
M_r: 142 18
Na₂SO₄·xH₂O(s) ⟶ Na₂SO₄(s) + xH₂O(g)
m/g: 3.22 1.42
Step 2. Calculate the mass of the water
Mass of H₂O = mass of Na₂SO₄·xH₂O – mass of Na₂SO₄
= 3.22 – 1.42 = 1.80 g
Step 3. Calculate the moles of each product
Na₂SO₄: [tex]n = \text{1.42 g} \times \dfrac{\text{1 mol}}{\text{142 g}} = \text{0.0100 mol}[/tex]
H₂O: [tex]n = \text{1.80 g} \times \dfrac{\text{1 mol}}{\text{18 g}} = \text{0.100 mol}[/tex]
Step 4. Calculate the molar ratios
[tex]\dfrac{\text{moles of Na$_{2}$SO$_{4}$}}{\text{moles of H$_{2}$O}} = \dfrac{0.0100}{0.100} = \dfrac{1}{10}[/tex]
[tex]\boxed{x = 10}[/tex] , so the formula of the compound is Na₂SO₄·10H₂O
A 75.0-liter canister contains 15.82 moles of argon at a pressure of 546.8 kilopascals. What is the temperature of the canister?
Answer:
312 KExplanation:
1) Data:
a) V = 75.0 liter
b) n = 15.82 mol
c) p = 546.8 kPa
d) T = ?
2) Formula:
Ideal gas equation: pV = nRTWhere:
n = number of molesV = volumep = absolute pressureT = absolute temperatureR = Universal Gas constat: 8.314 kPa - liter / K-mol3) Solution:
a) Solve the equation for T:
T = pV / (nR)b) Substitute and compute:
T = 546.8 kPa × 75.0 l iter / (15.82 mol × 8.314 kPa-liter/K-mol) = 312 K(since the volume is expressed with 3 significant figures, the answer must show also 3 significant figures)
A student increases the temperature of a 200cm3 balloom from 60 degress C to 180 degrees C. What will the new volume of the balloon be? (Be careful with units)
600cm^3
100cm^3
236cm^3
272cm^3
Answer:
The new volume of the balloon is 600cm³
Explanation:
Given parameters:
Initial Volume, which is V₁ = 200cm³
Initial temperature, T₁ = 60°C
Final temperature T₂ = 180°C
Final Volume V₂ =?
To solve this kind of problem, we apply one of the gas laws that shows the relationship between volume and temperature.
This law is the Charles law, it states that " the volume of a fixed mass of a gas is directly proportional to its absolute temperature if pressure is constant".
It is simply expressed as:
V₁/T₁ = V₂/T₂
Since our unknown is V₂, we make it the subject of the expression given above:
V₂ = V₁T₂/T₁
Now input the corresponding values and solve:
V₂ = 200 x 180 / 60
V₂ = 36000/60
V₂ = 600cm³
The new volume of the balloon is 600cm³