Answer:
1.44 × 10⁻⁶
Explanation:
Step 1: Given data
Concentration of the acid (Ca): 1.21 MpH of the solution: 2.88Step 2: Calculate the concentration of H⁺ ions
We will use the definition of pH.
pH = -log [H⁺]
[H⁺] = antilog -pH = antilog -2.88 = 1.32 × 10⁻³ M
Step 3: Calculate the acid dissociation constant of the acid (Ka)
For a weak monoprotic acid, we will use the following expression.
Ka = [H⁺]²/Ca
Ka = (1.32 × 10⁻³)²/1.21 = 1.44 × 10⁻⁶
I need help with the practice question at the bottom. Thank you.
Explanation:
For this question, we apply the equation: Q = mCp AT Where m is the mass of the substance, Cp
is its specific heat capacity and AT is the
temperature change. Q = 896 x 0.45 x (5-94)
Q = -35884.8 Joules
So about -36 kilojoules of heat is released.
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What type of a liquid will have a pH value equal to 12? (1 point)
Basic
Neutral
Strong acid
Weak aci
Answer: it will be basic
pH that ranges from 0-6 are acid
pH of EXACTLY 7 is neutral
pH greater than 7 are strongly basic or base
Identify the change in state that does NOT have an increase in entropy. Identify the change in state that does NOT have an increase in entropy. water evaporating dry ice subliming steam condensing water boiling popsicle melting
Answer:
condensing water
Explanation:
Entropy refers to the level of disorderliness in a system. The entropy of liquids is greater than that of solids. The entropy of gases is greater than that of liquids.
A process of physical change involving a change of state from solid to liquid or liquid to gas is accompanied by increase in entropy.
However, a change of state involving a change from liquid to solid or gas to liquid is accompanied by decrease in entropy.
Hence, steam condensing to water leads to decrease and not increase in entropy of the system.
What is unit? Write down the units of mass, temperature and power
Explanation:
a single thing, person, or group forming part of a whole There are 36 units in my apartment building. the least whole number : one. a fixed quantity (as of length, time, or value) used as a standard of measurement An inch is a unit of length.mass=kilogram (kg)
temperature=kelvin
power=watt
hope it helps
stay safe healthy and happy..The total entropy of a system and its surroundings always increases for a spontaneous process. This is a statement of
Answer:
second law of thermodynamics
Explanation:
According to the second law of thermodynamics, the total entropy of a system and its surroundings always increases for a spontaneous process.
Entropy is defined as the degree of disorderliness of a system. The entropy of a system never remains constant. It either increases or decreases in a process. The total entropy is the sum of the entropy of the system and its surrounding. The total entropy must increase in a spontaneous process.
Thus, the implication of this law is that even, if the entropy of a system decreases, this must be compensated for by increase in entropy of the surroundings in order for the process to be spontaneous.
The speed of sound depends on the __?_____ and ____?____ of the medium through which it travels
Answer:
Density and rigidity
In water, Vanillin, C8H8O3, has a solubility of 0.070 moles of vanillin per liter of solution at 25C. What will be produced if 5.00 g of vanillin are added to 1 L of water at 25 C?
Answer:
The full amount (5.00 g) will be dissolved in 1 L of water at 25°C.
Explanation:
The molecular weight (MW) of Vanillin (C₈H₈O₃) is calculated from the chemical formula as follows:
MW(C₈H₈O₃) = (12 g/mol x 8) + (1 g/mol x 8) + (16 g/mol x 3) = 152 g/mol
If 0.070 mol of C₈H₈O₃ are soluble per liter of water at 25°C, the maximum mass that can be dissolved in 1 L is:
0.070 mol x 152 g/mol = 10.64 g
Since 5.00 g is lesser than the maximum amount that can be dissolved (10.64 g), the added amount will be completely dissolved in 1 L of water at 25°C.
. Gastric juice, the digestive fluid produced in the stomach, contains hydrochloric acid, HCl. Milk of Magnesia, a suspension of solid Mg(OH)2 in an aqueous medium, is sometimes used to neutralize excess stomach acid. Write a complete balanced equation for the neutralization reaction, and identify the conjugate acid-base pairs.
Answer:
Mg(OH)2 + 2HCI = MgCI2 + 2H2O
Explanation:
Please correct me if I am wrong
A cation is a
negative electrode.
negatively charged ion.
positively charged ion.
positive electrode
Answer:
Each electrode attracts ions that are of the opposite charge. Positively charged ions, or cations, move toward the electron-providing cathode, which is negative; negatively charged ions, or anions, move toward the positive anode.
which of the following is not an instance of benefit in from gases ?
1) filling thermometers
2) inflating tyres
3) in LP gas cylinders
4) in pressure cookers
Answer:
1) filling thermometers
Explanation:
thermometers are filled with liquid mercury
Please help meee! Chemistry!
P=18000000/6 zeros. not sure how to do rest
Explanation:
a) [tex]n = \dfrac{PV}{RT} = \dfrac{(1.8×10^7\:\text{Pa})(3\:\text{L})}{(8310\:\text{L•Pa/mol•K})(300\:\text{K})}[/tex]
[tex]\:\:\:\:\:\:\:= 21.7\:\text{mol}[/tex]
b) [tex]P = \dfrac{nRT}{V}[/tex]
[tex]\:\:\:\:\:\:\:\:\:= \dfrac{(50\:\text{mol})(8310\:\text{L•Pa/mol•K})(300\:K)}{(3\:L)}[/tex]
[tex]\:\:\:\:\:\:\:\:\:=4.2×10^7\:\text{Pa}[/tex]
this was in my science test just want to see if anyone knows?? the wording is so confusing
the relative atomic mass of an element compares the mass of an atom of an element with the mass of an atom of.......
Answer:
the molar mass of the element
When we react a weak acid with a strong base of equal amounts and concentration, the component of the reaction that will have the greatest effect on the pH of the solution is: Select the correct answer below:_________
a. the reactant acid
b. the reactant base
c. the conjugate acid of the strong base
d. the conjugate base of the weak acid
Answer:
d. the conjugate base of the weak acid
Explanation:
The strong base (BOH) is completely dissociated in water:
BOH → B⁺ + OH⁻
The resulting conjugate acid (OH⁻) is a weak acid, so it remains in solution as OH⁻ ions.
By other hand, the weak acid (HA) is only slightly dissociated in water:
HA ⇄ H⁺ + A⁻
The resulting conjugate base (A⁻) is a weak base. Thus, it reacts with H⁺ ions from water to form HA, increasing the concentration of OH⁻ ions in the solution.
Therefore, the resulting solution will have a pH > 7 (basic).
How many doubtful digit(s) is/are allowed in any measured quantity?
(Only 3 choices.)
A.) 1
B.) 2
C.) zero
Answer:
zero
Explanation:
I I think one should be so accurate with measurements and experiments
Plz!!!!Plz!!!!!help help
Answer:
false
Explanation:
category 1 is the worst
How long must a 40.0 amp current flow through a solution of iron(III) chloride in order to produce 5.00 moles of iron?
Answer:
10.1 h
Explanation:
Let's consider the reduction half-reaction of iron from an aqueous solution of iron (III) chloride.
Fe³⁺(aq) + 3 e⁻ ⇒ Fe(s)
We can calculate the time required to produce 5.00 moles of Fe using the following relationships.
1 mole of Fe is produced when 3 moles of electrons circulate.1 mole of electrons has a charge of 96486 C (Faraday's constant).1 A = 1 C/s.1 h = 3600 s.[tex]5.00molFe \times \frac{3 mole^{-} }{1molFe} \times\frac{96486C}{1mole^{-} } \times \frac{1s}{40.0C} \times \frac{1h}{3600s} = 10.1 h[/tex]
Gaseous methane will react with gaseous oxygen to produce gaseous carbon dioxide and gaseous water . Suppose 9.6 g of methane is mixed with 64.9 g of oxygen. Calculate the maximum mass of water that could be produced by the chemical reaction. Round your answer to significant digits.
Answer:
21.6 g
Explanation:
The reaction that takes place is:
CH₄ + 2O₂ → CO₂ + 2H₂OFirst we convert the given masses of both reactants into moles, using their respective molar masses:
9.6 g CH₄ ÷ 16 g/mol = 0.6 mol CH₄64.9 g O₂ ÷ 32 g/mol = 2.03 mol O₂0.6 moles of CH₄ would react completely with (2 * 0.6) 1.2 moles of O₂. As there are more O₂ moles than required, O₂ is the reactant in excess and CH₄ is the limiting reactant.
Now we calculate how many moles of water are produced, using the number of moles of the limiting reactant:
0.6 mol CH₄ * [tex]\frac{2molH_2O}{1molCH_4}[/tex] = 1.2 mol H₂OFinally we convert 1.2 moles of water into grams, using its molar mass:
1.2 mol * 18 g/mol = 21.6 gA 1.19 g sample of an unknown halogen occupies 109 mL at 398 K and 1.41 atm. What is the identity of the halogen
Answer:
The halogen is Iodine.
Explanation:
Using the ideal gas equation, we find the number of moles of gas present, n.
PV = nRT where P = pressure of gas = 1.41 atm, V = volume of gas = 109 mL = 0.109 L, n = number of moles of gas, R = molar gas constant = 0.082 L-atm/mol-K and T = temperature of gas = 398 K
Since PV = nRT, making n subject of the formula, we have
n = PV/RT
substituting the values of the variables into the equation, we have
n = 1.41 atm × 0.109 L/(0.082 L-atm/mol-K × 398 K)
n = 0.15369 atm-L/32.636 L-atm/mol
n = 0.0047 mol
Since n = m/M where m = mass of gas = 1.19 g and M = relative molecular mass of gas
So, M = m/n
M = 1.19 g/0.0047 mol
M = 252.7 g
Since halogens are diatomic the relative atomic mass is M/2 = 252.7g/2 = 126.34 g
From tables, the only halogen with this atomic mass is Iodine.
So, the halogen is Iodine.
Which mechanisms is most significant in returning the ion concentrations to the resting state?
Answer:
Active transport by the Na+-K+ pump
Explanation:
Active transport by the Na+-K+ pump
Maintenance (and restoration) of the resting ion concentrations depends on the Na+-K+ pump. Once gated ion channels are closed, the combined action of the pump and ion leakage (particularly that of K+) establishes a resting membrane potential in a typical neuron of around âˆ'70 mV.
What are the concentrations of hydronium and hydroxide ions in a solution with pH 2.6?
Please help omg. Ive been stuck for 15 minutes
Answer:
The concentrations of hydronium and hydroxide ions in a solution with pH 2.6 are 2.51*10⁻³ and 3.98*10⁻¹² respectively.
Explanation:
pH is a measure of the acidity or alkalinity of an aqueous solution. The pH indicates the concentration of hydrogen ions present in certain solutions. Mathematically it is defined as the opposite of the base 10 logarithm or the negative logarithm of the activity of hydrogen ions, whose equation is
pH= -log [H⁺]
So, being pH= 2.6 and replacing in the definition of pH:
2.6= -log [H⁺]
[tex][H^{+} ]=10^{-2.6}[/tex]
[H⁺]=2.51*10⁻³
pOH is a measure of the concentration of hydroxide ions (OH⁻). The sum between the pOH and the pH results in 14:
pOH + pH= 14
So, being pH= 2.6:
pOH + 2.6= 14
pOH= 14 - 2.6
pOH= 11.4
The pOH is defined as the negative logarithm of the activity of the hydroxide ions. That is, the concentration of OH⁻ ions:
pOH= - log [OH⁻]
Being pOH= 11.4 and replacing
11.4= -log [OH⁻]
[tex][OH^{-} ]=10^{-11.4}[/tex]
[OH⁻]= 3.98*10⁻¹²
The concentrations of hydronium and hydroxide ions in a solution with pH 2.6 are 2.51*10⁻³ and 3.98*10⁻¹² respectively.
Which event would be impossible to explain by using John Dalton's model of the atom?
Answer:
That is, the atom is a solid and indivisible mass. However, the fenomenom by which an iron atom emits particles when it is struck by light (known as the photoelectric effect) can not be explaind by this indivisible atom model.
In some sheep, the presence of horns is produced by an autosomal allele that is dominant in males and recessive in females.A horned female is crossed with a hornless male. One of the resulting F1 females is crossed with a hornless male. What proportion of the male and female progeny from this cross will have horns?(5 marks)
Answer:
1/2 f1 will cross
Explanation:
answer it
What kind of light would an electron experiencing n=4 to n=2 drop emit?
Hi there!
[tex]\large\boxed{\text{Visible Light.}}[/tex]
According to the diagram and the arrows, a drop from level 4 (n = 4) to level 2 (n = 2) produces orange visible light.
[tex]\red\large{{}}[/tex]
A 2,31M solution of trans-4-methyl-2-pentene (C6H12, 85mL) is combined with 7,5mL of 3,55M elemental bromine to form an addition product. With an expectation of 100% yield, more than 25mmols of elemental bromine would be consumed during this chemical process.
a. True
b. False
Answer:
The statement is false
Explanation:
Number of moles of alkene = 2.31 × 85/1000 = 0.196 moles
Number of moles of Br2 = 3.55 × 7.5/1000 = 0.0266 moles
Given that the reaction is 1:1
1 mole of alkene reacts with 1 mole of bromine
0.196 moles of alkene should react with 0.196 moles of bromine
Hence, to achieve 100%yield, 0.196 moles of bromine and not 25mmols of elemental bromine
When 1-methylcyclopentene undergoes acid catalyzed hydration, the major product formed is 1-methylcyclopentanol. What change(s) in the reactants would result in 2-methylcyclopentanol being the major product
Answer:
Conversion of 1-methyl cyclopentene to 2-methyl cyclopentanol.
Explanation:
When alkenes react with diborane followed by the reaction with hydrogen peroxide and NaOH then the least substituted carbon in the double bond will be substituted.
The formation of 2-methyl cyclopentanol from 1-methyl cyclopentene is shown below:
Cal is titrating 57.7 mL of 0.311 M HBr with 0.304 M Ba(OH)2. How many mL of Ba(OH)2 does Cal need to add to reach the equivalence point?
Answer:
118.06 mL
Explanation:
The neutralization reaction between HBr (acid) and Ba(OH)₂ (base) is the following:
2HBr + Ba(OH)₂ → BaBr₂ + 2H₂O
According to the equation, 2 moles of HBr react with 1 mol Ba(OH)₂. Thus, at the equivalence point the moles of acid and base react completely:
2 moles HBr = 1 mol Ba(OH)₂
We can replace the moles by the product of the molar concentration (M) and volume (V):
2 x (M HBr) x (V HBr) = M Ba(OH)₂ x V Ba(OH)₂
Now, we introduce the data in the equation to calculate the volume in mL of Ba(OH)₂:
V Ba(OH)₂ = (2 x (M HBr) x (V HBr))/M Ba(OH)₂
= (2 x 0.311 M x 57.7 mL)/(0.304 M)
= 118.06 mL
Therefore, 118 mL of Ba(OH)₂ are needed.
An unknown weak acid with a concentration of 0.530 M has a pH of 5.600. What is the Ka of the weak acid
Answer:
Ka = 3.45x10⁻⁶
Explanation:
First we calculate [H⁺], using the given pH:
pH = -log[H⁺][H⁺] = [tex]10^{-pH}=10^{-5.6}[/tex] [H⁺] = 2.51x10⁻⁶ MTo solve this problem we can use the following formula describing a monoprotic weak acid:
[H⁺] = [tex]\sqrt{C*Ka}[/tex]We input the data that we already know:
2.51x10⁻⁶ = [tex]\sqrt{0.530*Ka}[/tex]And solve for Ka:
Ka = 3.45x10⁻⁶Imagine you are celebrating a birthday in December and need balloons. The temperature in the
store where you are purchasing the balloons is approximately 25°C and each balloon is filled
to a volume of 2 liters to obtain maximum pressure.
Use the gas laws to explain what will happen to the volume and pressure of the gas in the
balloon when go outside, where the temperature is 0°C. Include both Charles's Law
and Gay-
Lussac's Law in your answer.
ILL GIVE BRAINIEST PLEASE HELP
A 25.0 mL sample of a saturated C a ( O H ) 2 solution is titrated with 0.029 M H C l , and the equivalence point is reached after 37.3 mL of titrant are dispensed. Based on this data, what is the concentration (M) of the hydroxide ion?
Answer:
0.043 M
Explanation:
The reaction that takes place is:
Ca(OH)₂ + 2HCl → CaCl₂ + 2H₂OFirst we calculate how many HCl moles reacted, using the given concentration and volume required to reach the equivalence point:
0.029 M HCl * 37.3 mL = 1.0817 mmol HCl = 1.0817 mmol H⁺As 1 mol of H⁺ reacts with 1 mol of OH⁻, in the 25.0 mL of the Ca(OH)₂ sample there are 1.0817 mmoles of OH⁻.
With that in mind we can calculate the hydroxide ion concentration in the original sample solution, using the calculated number of moles and given volume:
1.0817 mmol OH⁻ / 25.0 mL = 0.043 MThe titration is termed the neutralization reaction with the acid and base. The concentration of hydroxide in the titration is 0.0865 M.
What is a neutralization reaction?The neutralization reaction is given as the reaction in which the acid and base react to form the salt and water, stabilizing the pH of the solution.
The neutralization of acid and base to identify the strength can be given as:
[tex]\rm M_V_1=M_2V_2[/tex]
Substituting the strength and the volume of calcium hydroxide and the HCl with the volume:
[tex]\rm 0.029\;M\;\times\;37.3\;mL=M_2\;\times\;25\;mL\\M_2=\dfrac{ 0.029\;M\;\times\;37.3\;mL}{25\;mL} \\M_2=0.0432\;M[/tex]
The strength of the calcium hydroxide in the reaction is 0.04326 M.
One molar unit of calcium hydroxide results in 2 molar units of hydroxide. The molar unit of hydroxide in 0.04326 M calcium hydroxide is:
[tex]\rm 1\;M\;Ca(OH)_2=2\;M\;OH^-\\\\0.04326\;M\;Ca(OH)_2=0.04326\;\times\;2\;M\;OH^-\\0.04326\;M\;Ca(OH)_2=0.0865\;M\;OH^-[/tex]
The concentration of hydroxide ion in the titration is 0.0865 M.
Learn more about molarity, here:
https://brainly.com/question/12127540
A cylinder contains 3.1 L of oxygen at 300 K and 2.7 atm. The gas is heated, causing a piston in the cylinder to move outward. The heating causes the temperature to rise to 610 K and the volume of the cylinder to increase to 9.4 L.
How many moles of gas are in the cylinder?
Express your answer using two significant figures.
Answer: The moles of gas present in the cylinder is 0.34 moles.
Explanation:
Given: [tex]P_{1}[/tex] = 2.7 atm, [tex]V_{1}[/tex] = 3.1 L, [tex]T_{1}[/tex] = 300 K
[tex]P_{2}[/tex] = ?, [tex]V_{2}[/tex] = 9.4 L, [tex]T_{2}[/tex] = 610 K
Formula used to calculate the final temperature is as follows.
[tex]\frac{P_{1}V_{1}}{T_{1}} = \frac{P_{2}V_{2}}{T_{2}}[/tex]
Substitute the values into above formula as follows.
[tex]\frac{P_{1}V_{1}}{T_{1}} = \frac{P_{2}V_{2}}{T_{2}}\\\frac{2.7 atm \times 3.1 L}{300 K} = \frac{P_{2} \times 9.4 L}{610 K}\\P_{2} = \frac{5105.7}{2820} atm\\= 1.81 atm[/tex]
Now, moles present upon heating the cylinder are as follows.
[tex]P_{2}V_{2} = n_{2}RT_{2}\\1.81 atm \times 9.4 L = n_{2} \times 0.0821 L atm/mol K \times 610 K\\n_{2} = \frac{17.014}{50.081} mol\\= 0.34 mol[/tex]
Thus, we can conclude that moles of gas present in the cylinder is 0.34 moles.
