Which of the following aqueous solutions has the lowest pH? Why?
a. 0.1 M HCl;
b. 0.1 M acetic acid (pKa = 4.86);
c. 0.1 M formic acid (pKa = 3.75
An ice cube melts in the hot sun. Is this exothermic or endothermic and
why?
Answer:
Endothermic
Explanation:
In order to melt the ice cube, heat is required, so the process is endothermic. Endothermic reaction In an endothermic reaction, the products are higher in energy than the reactants. Therefore, the change in enthalpy is positive, and heat is absorbed from the surroundings by the reaction.
When is a chemical equation considered balanced
Answer:
If each side of the equation has the same number of atoms of a given element, that element is balanced. If all elements are balanced, the equation is balanced.
Explanation:
A 1.00 gram sample of which of the following compounds contains the greatest mass of oxygen? And explain.
1. K2O2
2. Na2O
3. BeO
Answer:
BeO will have the greatest mass composition of oxygen
Explanation:
To solve this problem, we would find the mass composition of oxygen in each of the given sample.
To find this mass composition, let us derive the molecular mass of the given species;
K₂O₂ = 2(39) + 2(16) = 110g/mol
Na₂O = 2(23) + 16 = 62g/mol
BeO = 9 + 16 = 25g/mol
Now; we know that mass of each sample is 1g;
mass composition of O in K₂O₂ = [tex]\frac{32}{110}[/tex] x 1= 0.29g
mass composition of O in Na₂O = [tex]\frac{16}{62}[/tex] x 1 = 0.26g
mass composition of O in BeO = [tex]\frac{16}{25}[/tex] x 1 = 0.64g
We can see that BeO will have the greatest mass composition of oxygen.
The mass composition of oxygen has been highest in BeO. Thus, option 3 is correct.
The molecular mass has been the mass of each element that has been present in the compound. The molecular mass of given compounds have been:
[tex]\rm K_2O_2[/tex] = 2(mass of K) + 2(mass of O)= 2 (39) + 2 (16)
= 110 g/mol
[tex]\rm Na_2O[/tex]= 2(mass of N) + mass of O= 2 (23) + 16
= 62 g/mol
BeO = mass of Be + mass of O= 9 + 16
= 23 g/mol
The mass composition of oxygen in 1 gram of the following compounds have been:
Mass composition = [tex]\rm \dfrac{Mass\;of\;Oxygen}{Molecular\;mass\;of\;compound}\;\times\;weight\;of\;sample[/tex]
[tex]\rm K_2O_2[/tex] = [tex]\rm \dfrac{32}{110}\;\times\;1\;gram[/tex][tex]\rm K_2O_2[/tex] = 0.29 grams
[tex]\rm Na_2O[/tex] = [tex]\rm \dfrac{16}{62}\;\times\;1\;gram[/tex][tex]\rm Na_2O[/tex] = 0.26 grams
BeO = [tex]\rm \dfrac{16}{23}\;\times\;1\;gram[/tex]BeO = 0.64 grams.
The mass composition of oxygen has been highest in BeO. Thus, option 3 is correct.
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Write the net ionic equation for the acid-base reaction
PH3(aq) + HCl(aq) - PH4Cl(aq)
Explanation:
i dont understand dont you already have the equation?
The net ionic equation for the acid-base reaction PH[tex]_3[/tex](aq) + HCl(aq) [tex]\rightarrow[/tex] PH[tex]_4[/tex]Cl(aq) is PH[tex]_3[/tex](aq) + H⁺ (aq) [tex]\rightarrow[/tex] PH[tex]_4[/tex]⁺ .
What is net ionic equation?Chemical reaction equations can be written in a variety of ways. Unbalanced chemical equations, which identify the species involved, balanced chemical equations, which identify the number and type of species, molecular equations, that also express compounds as molecules rather than component ions, and net ionic equations, which only address the species which contribute to a reaction, are some of the most popular.
A chemical equation for just a process known as the net ionic equation only includes the species that are really involved in the reaction.
PH[tex]_3[/tex](aq) + HCl(aq) [tex]\rightarrow[/tex] PH[tex]_4[/tex]Cl(aq)
PH[tex]_3[/tex](aq) + H⁺ (aq) + Cl⁻ (aq) [tex]\rightarrow[/tex] PH[tex]_4[/tex]⁺ (aq) + Cl⁻ (aq)
PH[tex]_3[/tex](aq) + H⁺ (aq) [tex]\rightarrow[/tex] PH[tex]_4[/tex]⁺
Therefore, the net ionic equation for the acid-base reaction is PH[tex]_3[/tex](aq) + H⁺ (aq) [tex]\rightarrow[/tex] PH[tex]_4[/tex]⁺ .
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How does Newton’s second law apply to the golf tee balanced on the hoop? How does Newton’s second law apply to the golf tee when the hoop is pulled away?
please answer asap
There are total three laws of newtons, first law of newtons, second law of newton and third law of newton. Therefore, when a golf club is subjected to an imbalanced force, its velocity changes, which is according to newton’s second law.
What is newton's second law?According to Newton's Second Law of Motion, acceleration (gaining speed) occurs when a force acts on a mass (object). Riding a bicycle is a great example of this rule of motion in action. The mass is represented by your bicycle. The force is generated by your leg muscles pulling on the pedals of your bicycle.
The ball remains balanced on the tee due to the balanced forces of gravity downhill and upward. Force equals mass multiplied by acceleration (f=ma). When a golf club is subjected to an imbalanced force, its velocity changes.
Therefore, when a golf club is subjected to an imbalanced force, its velocity changes, which is according to newton’s second law.
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What is the density of a glass piece that has mass of 18 g and a volume of 24 mL?
Answer:
The answer is 0.75 g/mLExplanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\ [/tex]
From the question we have
[tex]density = \frac{18}{24} = \frac{3}{4} \\ [/tex]
We have the final answer as
0.75 g/mLHope this helps you
plzzzzz Plzzz Wil givr brainleast which type of weathering causes the mineral composition of rocks to change
Answer:
Chemical
Explanation:
Cause it is
What most likely to cuase the rate of a chemical reaction to increase
Answer:
An increase on temperature.
Explanation:
Answer: adding a catalyst or increasing temperature
Explanation:
Hello I was wondering if anyone knew how to draw the molecular geometry of fentanyl. I already did the Lewis structure.
Answer:
i dont
Explanation:
Name 2 ways heat can be transferred through convention.
Answer:
Heat can travel from one place to another in three ways: Conduction, Convection and Radiation. Both conduction and convection require matter to transfer heat. If there is a temperature difference between two systems heat will always find a way to transfer from the higher to lower system.
Explanation:
What is the oxidation number of P in PF6−?
Which are correct ???
Answer:
last one
Explanation:
endothermic reactions release energy
What mass is contributed by Br-79?
Answer:
Calculate the mass of BR -79? Bromine has 2 naturally occurring isotopes (Br-79 and Br-81) and has an atomic mass of 79.904 amu
Explanation:
if i get this wrong srry
Which temperature is warmest
A. 0°C
B. 273 K
C. 32°F
D. 30°C
Answer:
your answer should be B.273 K
Explanation:
How much heat would be required to convert 5.31 mol of a pure substance from a liquid at 40.0°C to a gas at 113.0°C?
Answer:
Q = 7.7 KJ
Explanation:
The complete question carries the following data:
Specific Heat Capacity of Liquid State = C(l) = 1.45 J/mol.°C
Specific Heat Capacity of Gaseous State = C(g) = 0.65 J/mol.°C
Boiling Temperature = Tb = 88.5°C
Heat of Vaporization = ΔH(vap) = 1.23 KJ/mol
Now, first we calculate the heat required (Q₁) to raise he temperature to boiling point:
Q₁ = n*C(l)*ΔT₁
where,
n = no. of moles = 5.31 mol
ΔT₁ = Temperature difference from 40°C to Tb = 88.5°C - 40°C = 48.5°C
Therefore,
Q₁ = (5.31 mol)(1.45 J/mol.°C)(48.5°C)
Q₁ = 373.4 J = 0.37 KJ
Now, we calculate the heat required (Q₂) to change its phase:
Q₂ = nΔH(vap)
Q₂ = (5.31 mol)(1.23 KJ/mol)
Q₂ = 6.53 KJ
Now, we calculate the heat required (Q₃) to raise he temperature to boiling point:
Q₃ = n*C(g)*ΔT₃
where,
n = no. of moles = 5.31 mol
ΔT₃ = Temperature difference from Tb to 113°C = 113°C - 88.5°C = 24.5°C
Therefore,
Q₃ = (5.31 mol)(0.65 J/mol.°C)(24.5°C)
Q₃ = 84.5 J = 0.08 KJ
So, the total heat required to convert 5.31 mol of this pure substance from a liquid at 40°C to a gas at 113°C is:
Q = Q₁ + Q₂ + Q₃
Q = 0.37 KJ + 6.53 KJ + 0.08 KJ
Q = 7.7 KJ
The total heat required to convert the pure substance from liquid to gas at the given temperature is 814 J.
The given parameters;
molar heat capacity of liquid, C(l) = 1.45 J/mol.⁰Cmolar heat capacity of gas, C(g) = 0.65 J/mol.⁰CThe total heat required to convert the pure substance from liquid to gas at the given temperature is calculated as follows;
[tex]Q = nc_l \Delta \theta + nc_g \Delta \theta \\\\ \Delta \theta = (113 - 40) = 73^0 C \\\\Q = (5.31 \ mol \times 1.45 \frac{J}{mol .\ ^0C} \times 73\ ^0C) + (5.31 \ mol \times 0.65 \frac{J}{mol .\ ^0C} \times 73 \ ^0C)\\\\Q = 814 \ J[/tex]
Thus, the total heat required to convert the pure substance from liquid to gas at the given temperature is 814 J.
"Your question is not complete, it seems to be missing the following information;"
How much heat would be required to convert 5.31 mol of a pure substance from a liquid at 40.0°C to a gas at 113.0°C? (molar heat capacity of liquid, C(l) is 1.45 J/mol.⁰C and molar heat capacity of gas, C(g) is 0.65 J/mol.⁰C).
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What are some foods that bacteria helps in the production of?
Answer:
yeasts, moulds, bread, beer, wine, ...
Explanation:
Which of the following conclusions about the two intermolecular forces is correct? X represents London dispersion forces, and Y represents ion-dipole forces. X represents dipole-dipole forces, and Y represents ion-dipole forces. X represents hydrogen bonding, and Y represents dipole-dipole forces. X represents London dispersion forces, and Y represents dipole-dipole forces.
Answer:
X represents London dispersion forces, and Y represents dipole-dipole forces.
Explanation:
Solubility
Mixtures and Solutions
Acellus
If 1.23 g of chlorine gas dissolves in
0.95 L of water at 15.6 psi, at what
pressure (in psi) would you be able
to dissolve 1.89 g in the same
amount of water?
The pressure : 23.48 psi
Further eplanationHenry's Law stated that the solubility of a gas is proportional to its partial pressure
Can be formulated
S = kH. P.
S = gas solubility, mol / L
kH = Henry constant, mol / L.atm
P = partial gas pressure
1.23 g Cl₂MW Cl₂ = 71 g/mol
mol of 1.23 g Cl₂ :
[tex]\tt mol=\dfrac{1.23}{71}=0.017[/tex]
Solubility O₂ : 0.017 mol/0.95 L =0.01789 mol/L
Henry's constant for O₂ :
P = 15.6 psi= 1.061517 atm
[tex]\tt S=kH.P\\\\kH=\dfrac{0.01789}{1,061517}=0.0169[/tex]
1.89 g Cl₂[tex]\tt \dfrac{1.89}{71}=0.026[/tex]
[tex]\tt S=0.026:0.95=0.027\\\\P=\dfrac{S}{kH}=\dfrac{0.027}{0.0169}=1.598~atm=23,48~psi[/tex]
Answer:24.0
Explanation:
What is the name of the process that is used to clean up environmental waste and how does it work?
Answer:
Environmental cleanup includes removal of heavy metals and other toxic contaminants from the environment and the process is called remediation.
When given the following: density = 0.79 g/mL and mass =8g (answer can be found in your reading) What is the volume of the object?
HELP ASAP!!!!!!!!!!!!!
Answer:
V = 10.12 mL
Explanation:
Given that,
Density, d = 0.79 g/mL
Mass, m = 8 g
We need to find the volume of the object. Density is equal to the mass per unit volume. It can be given by :
[tex]d=\dfrac{m}{V}[/tex]
Where V is the volume of the object
[tex]V=\dfrac{m}{d}\\\\=\dfrac{8\ g}{0.79\ g/mL}\\\\V=10.12\ mL[/tex]
So, the volume of the object is 10.12 mL.
Salt is water solution is made salt or water
Answer:
Both
Explanation:
because salt water comes from water mixing with salt
The critical resolved shear stress for a metal is 35 MPa. Determine the maximum possible yield strength (in MPa) for a single crystal of this metal that is pulled in tension.
Answer:
The maximum possible yield strength for a single crystal is 70 MPa.
Explanation:
To find the maximum possible yield strength for a single crystal we need to use the following equation:
[tex]\sigma_{y} = \frac{\tau_{CRSS}}{m_{max}}[/tex]
Where:
[tex]m_{max}[/tex] is the maximum value for Schmid factor
[tex]\tau_{CRSS}[/tex] is the critical resolved shear stress = 35 MPa
[tex] \sigma_{y}[/tex] is the yield strength =?
The Schmid factor is given by:
[tex]m = cos(\phi)cos(\lambda)[/tex]
And its maximum value is obtained when λ = 45° and Φ = 45°, so:
[tex] m = cos(45)cos(45) = 0.5 [/tex]
Finally, the maximum possible yield strength is:
[tex]\sigma_{y} = \frac{\tau_{CRSS}}{m_{max}} = \frac{35 MPa}{0.5} = 70 MPa[/tex]
Therefore, the maximum possible yield strength for a single crystal is 70 MPa.
I hope it helps you!
PLEASE HELP IM TIMED
Which of the following is not an oxidation-reduction reaction?
Upper X e upper F subscript 6 (s) right arrow upper X e upper F subscript 4 (s) plus upper F subscript 2 (g).
2 upper C s (s) plus upper I subscript 2 (g) right arrow 2 upper C s upper I (s).
2 upper H subscript 2 upper S upper O subscript 4 (a q) plus 2 upper B a (upper O upper H) subscript 2 (a q) right arrow 2 upper B a upper S upper O subscript 4 upper H subscript 2 upper O (l).
Upper Z n (s) lus 2 upper A g upper N upper O subscript 3 (a q) right arrow upper Z n (upper N upper O subscript 3) subscript 2 (a q) plus upper A g (s).
Answer: choice 2
Explanation:
PLEASE HELP ME!!!!!!!!!!!!!!!!!!!
WRITE A SHORT PASSAGE ON HOW FIBRES ARE SPUN
HELPPP WILL MARK AS BRAINLIEST
Answer: Spun yarn is made by twisting staple fibers together
To make a cohesive thread Or “single”. Twisting fibers, into yarn in the process called spinning can be dated back to the upper Paleolithic. Yarn spinning was one of the first processes to be industrialized.
Explanation:
What is the Atomic number of 12
Answer:
atomic number of 12 is MG
Explanation:
Magnesium
Calculate the number of moles of solute in 431.9 L of 0.722 M sodium cyanide.
Answer:
[tex]312 \ mol \ solute[/tex]
General Formulas and Concepts:
Chemistry
Molarity = moles of solute / liters of solutionExplanation:
Step 1: Define variables
M = 0.722
L = 431.9
m = x
Step 2: Solve for x
Substitute: [tex]0.722 \ M=\frac{x \ mol}{431.9 \ L}[/tex]Isolate x: [tex]311.832=x \ mol[/tex]Rewrite: [tex]x=311.832 \ mol[/tex]Step 3: Check
Our smallest sig figs is 3. Follow sig figs rules.
[tex]311.832 \ mol \approx 312 \ mol \ solute[/tex]
i will give the first person brainliest! please helppp
okay so the Answer is c
What volume of a 0.155 M potassium hydroxide solution is required to neutralize 25.7 mL of a 0.388 M hydrobromic acid solution
Answer: Therefore, the volume of a 0.155 M potassium hydroxide solution is 56.0 ml
Explanation:
Molarity of a solution is defined as the number of moles of solute dissolved per Liter of the solution.
According to the neutralization law,
[tex]n_1M_1V_1=n_2M_2V_2[/tex]
where,
[tex]M_1[/tex] = molarity of [tex]HBr[/tex] solution = 0.338 M
[tex]V_1[/tex] = volume of [tex]HBr[/tex] solution = 25.7 ml
[tex]M_2[/tex] = molarity of [tex]KOH[/tex] solution = 0.155 M
[tex]V_2[/tex] = volume of [tex]KOH[/tex] solution = ?
[tex]n_1[/tex] = valency of [tex]HBr[/tex] = 1
[tex]n_2[/tex] = valency of [tex]KOH[/tex] = 1
[tex]1\times 0.338\times 25.7=1\times 0.155\times V_2[/tex]
[tex]V_2=56.0ml[/tex]
Therefore, the volume of a 0.155 M potassium hydroxide solution is 56.0 ml
Question in picture!!!!!!
Answer:
6 atoms
Explanation:
