Answer:
pH = 1.92Explanation:
[H+] = 0.1x0.03x2 + 0.2x0.03 = 0.012 mol
[OH-] = 0.001x0.05x2 = 0.0001 mol
=> [H+] dư = 0.012 - 0.0001 =0.0119 mol
pH = -log[H+] = 1.92
Determine whether each description relates to wavelength or frequency.
a. Increases as energy decreases
b. Often measured in units such as nanometers (nm)
c. Often measured in units such as Hertz (Hz)
d. Increases as energy increases
e. A measure of cycles per unit time
f. A measure of distance
g. Frequency Wavelength
Answer:
Wavelength
a. Increases as energy decreases
b. Often measured in units such as nanometers (nm)
f. A measure of distance
Frequency
c. Often measured in units such as Hertz (Hz)
d. Increases as energy increases
e. A measure of cycles per unit time
Explanation:
Wavelength increases when the energy decreases whereas frequency increases as energy increases. Wavelength is measured in nanometers (nm) whereas frequency is measured in hertz. Frequency refers to the number of cycles in a unit of time while on the other hand, the distance between successive crests of a wave, especially in a sound wave or electromagnetic wave is known as wavelength.
Identify the isoelectronic elements.
i. Cl-, F-, Br-, I-, At-
ii. Ne, Ar, Kr, Xe, He
iii. N3-, S2-, Br-, Cs+, Sr2+
iv. N3-, O2-, F-, Na+, Mg2+
v. Li+, Na+, K+, Rb+,Cs+
Answer:
iv. N³⁻, O²⁻, F⁻, Na⁺, Mg²⁺
Explanation:
Isoelectronic elements are those that have the same number of electrons. So, if at least 2 elements differ in their number of electrons, the series is not of isoelectronic elements.
To know the number of electrons we will consider the atomic number and add electrons if it is an anion and subtract electrons it is a cation.
Identify the isoelectronic elements.
i. Cl⁻, F⁻, Br⁻, I⁻, At⁻. NO. Cl⁻ has 18 electrons (17+1) and F⁻ has 10 electrons (9+1). ii. Ne, Ar, Kr, Xe, He. NO. Ne has 10 electrons and Ar has 18. iii. N³⁻, S²⁻, Br⁻, Cs⁺, Sr²⁺. NO. N³⁻ has 10 electrons (7+3) and S²⁻ has 18 (16+2).iv. N³⁻, O²⁻, F⁻, Na⁺, Mg²⁺. YES. They all have 10 electrons v. Li⁺, Na⁺, K⁺, Rb⁺, Cs⁺. NO. Li⁺ has 2 electrons (3-1) and Na⁺ has 10 (11-1).In an activity in which dye was added to two beakers of water, the beaker on the hot
plate mixed the dye into the water much faster then the beaker at room temperature.
Which statement best explains why there is a difference in the speed at which the
dye mixed in the water between the two beakers.
Liquid hexane
(CH,(CH), CH) will react with gaseous oxygen (0) to produce gaseous carbon dioxide (CO2) and gaseous water (1,0). Suppose 1.72 g
of hexane is mixed with 8.0 g of oxygen. Calculate the maximum mass of water that could be produced by the chemical reaction. Be sure your answer has the
correct number of significant digits.
Answer: The mass of [tex]H_2O[/tex] produced is 2.52 g
Explanation:
The number of moles is defined as the ratio of the mass of a substance to its molar mass. The equation used is:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] ......(1)
For hexane:Given mass of hexane = 1.72 g
Molar mass of hexane = 86.18 g/mol
Putting values in equation 1, we get:
[tex]\text{Moles of hexane}=\frac{1.72g}{86.18g/mol}=0.020mol[/tex]
For oxygen gas:Given mass of oxygen gas = 8.0 g
Molar mass of oxygen gas= 32 g/mol
Putting values in equation 1, we get:
[tex]\text{Moles of water}=\frac{8.0g}{32g/mol}=0.25mol[/tex]
The chemical equation for the combustion of hexane follows:
[tex]2C_6H_{14}+19O_2\rightarrow 12CO_2+14H_2O[/tex]
By stoichiometry of the reaction:
If 2 moles of hexane reacts with 19 moles of oxygen gas
So, 0.020 moles of hexane will react with = [tex]\frac{19}{2}\times 0.020=0.19mol[/tex] of oxygen gas
As the given amount of oxygen gas is more than the required amount. Thus, it is present in excess and is considered as an excess reagent.
Thus, hexane is considered a limiting reagent because it limits the formation of the product.
By the stoichiometry of the reaction:
If 2 moles of hexane produces 14 moles of [tex]H_2O[/tex]
So, 0.020 moles of hexane will produce = [tex]\frac{14}{2}\times 0.020=0.14mol[/tex] of [tex]H_2O[/tex]
We know, molar mass of [tex]H_2O[/tex] = 18 g/mol
Putting values in above equation, we get:
[tex]\text{Mass of }H_2O=(0.14mol\times 18g/mol)=2.52g[/tex]
Hence, the mass of [tex]H_2O[/tex] produced is 2.52 g
Write a balanced, net ionic equation for the precipitation reaction of CaCl2 and Cs3PO4 in an aqueous solution. Remember to include the proper physical states and charges of ions.
Answer:
3Ca²⁺(aq) + 2PO4³⁻(aq) → Ca3(PO4)2(s)
Explanation:
The calcium of CaCl2 reacts with the phosphate ion od Cs3PO4 to produce the insoluble salt Ca3(PO4)2 and CsCl. The unbalanced reaction is:
CaCl2(aq) + Cs3PO4(aq) → Ca3(PO4)2(s) + CsCl(aq)
To balance the calciums:
3CaCl2(aq) + Cs3PO4(aq) → Ca3(PO4)2(s) + CsCl(aq)
The chlorides:
3CaCl2(aq) + Cs3PO4(aq) → Ca3(PO4)2(s) + 6CsCl(aq)
And the Cs:
3CaCl2(aq) + 2Cs3PO4(aq) → Ca3(PO4)2(s) + 6CsCl(aq)
This is the balanced reaction, the ionic equation is:
3Ca²⁺(aq) + 6Cl⁻(aq) + 6Cs⁺(aq) + 2PO4³⁻(aq) → Ca3(PO4)2(s) + 6Cs⁺(aq) + 6Cl⁻(aq)
Subtracting the ions that don't react:
3Ca²⁺(aq) + 2PO4³⁻(aq) → Ca3(PO4)2(s)This is the net ionic equation
The balanced, net ionic equation for the precipitation reaction of CaCl₂ and Cs₃PO₄ in an aqueous solution can be written as follows:
3Ca²⁺(aq) + 2PO₄³⁻(aq) -> Ca₃(PO₄)₂(s)
A balanced equation is a chemical equation in which the number of atoms of each element on both sides of the equation is equal. It follows the law of conservation of mass, which states that matter cannot be created or destroyed in a chemical reaction.
In a balanced equation, the coefficients in front of each compound or molecule indicate the number of moles or molecules involved in the reaction. By adjusting these coefficients, the equation is balanced in terms of both mass and charge.
In this equation, Ca²⁺ ions from calcium chloride (CaCl₂) combine with PO₄³⁻ ions from cesium phosphate (Cs₃PO₄) to form solid calcium phosphate (Ca₃(PO₄)₂). The net ionic equation represents only the species directly involved in the reaction and excludes spectator ions, which do not participate in the formation of the precipitate. The physical states are denoted as (aq) for aqueous and (s) for solid.
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What happens to the concentration of hydron What happens to the pH of a buffer when a small amount of acid is added? It will decrease by 10 points. It will increase by 10 points. It will stay about the same.ium ions as the pH of a solution increases? Disabled A. hydronium ion concentration increases Student Selected Incorrect B. hydronium ion concentration stays the same Disabled C. hydronium ion concentration decreases
Answer:
B
Explanation:
the concentration will be the same disabled
Which type of chemistry studies the chemical reactions that occur in the human body?
O biochemistry
O materials chemistry
O physical chemistry
O environmental chemistry
Answer:
Which type of chemistry studies the chemical reactions that occur in the human body? .
biochemistry
The correct answer is biochemistry.
What is Biochemistry?Biochemistry is the study of the chemical process that occur in living things.Why other Options are incorrect?Materials Chemistry is the section of Materials Science and Engineering that investigates the chemical nature of materials.Physical chemistry is the branch of chemistry that deals with physical structure of chemical compound. Environmental chemistry is the study of chemical process that deals with environment.
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Which of the following statements is true?
A. Igneous rocks usually form in visible layers.
B. Metamorphic rocks are formed from eroded sediment
C. Sedimentary rocks form from cooling magma
D. The rock cycle recycles rock on Earth's surface.
Answer:
b
Explanation:
bc why not
Acetic acid has a Ka of 1.75x10^-5. The weak acid approximation (for this class) would be allowed for which of the following initial concentrations of acetic acid?
a. 1.75E^-6
b. 1.75E^-5
c. 0.00175
d. 0.0175
e. 0.175
Answer:
e. 0.175
Explanation:
The equilibrium constant of a reaction is the value of its reaction quotient when at equilibrium. The equilibrium concentration of a product or reactant depends on the initial concentrations and equilibrium constant of the reactants and products.
The weak acid approximation depends on the initial concentration and equilibrium constant ([tex]K_a[/tex]). The farther the initial concentration and equilibrium constant are from one another, the more likely the approximation would be valid.
At 900 oC, Kp = 1.04 for the reactionCaCO31(s) arrow CaO (s) + CO2 (g)At a low temperature, dry ice (solid CO2), calcium oxide, and calcium carbonate are introduced into a 50.0-L reaction chamber. The temperature is raised to 900 oC, resulting in the dry ice converting to gaseous CO2. For the following mixtures, will the initial amount of calcium oxide increase, decrease, or remain the same as the system moves toward equilibrium at 9000 oC?a. 655 gCaCO3, 95.0 gCaO, PCO2 = 2.55 atm.b. 780 gCaCO3, 1.00 gCaO, PCO2 = 1.o4 atm.c. 0.14 gCaCO3, 5000 gCaO,PCO2 = 1.04 atm.d. 715 gCaCO3, 813 gCaO, PCO2 = 0.211 atm.
Answer:
a)the reaction will proceed to the left, the mass of CaO will decrease.
b)the reaction is in equilibrium, mass of CaO will not change.
c)the reaction is in equilibrium, mass of CaO will not change.
d) the reaction will proceed to the right, the mass of CaO will increase.
Explanation:
Step 1: Data given
At 900°C, Kp = 1.04 ( Kp is only for compounds that are in gaseous state)
Volume of the chamber = 50.0L
Temperature is raised to 900 °C
Step 2: The reaction
CaCO31(s) ⇔ CaO (s) + CO2 (g)
Kp for CO2 = 1.04
Step 3: First mix : 655g CaCO3, 95.0g CaO, PCO2 = 2.55 atm
We only consider CO2 here
pCO2 > Kp this means the reaction will proceed to the left, the mass of CaO will decrease.
Step 4: 780g CaCO3, 1.00g CaO, PCO2 = 1.04 atm.
We only consider CO2 here
pCO2 = Kp this means the reaction is in equilibrium, mass of CaO will not change.
Step 5: 0.14g CaCO3, 5000g CaO, PCO2 = 1.04 atm
We only consider CO2 here
pCO2 = Kp this means the reaction is in equilibrium, mass of CaO will not change.
Step 6: 715g CaCO3, 813g CaO, PCO2 = 0.211 atm
We only consider CO2 here
pCO2 < Kp this means the reaction will proceed to the right, the mass of CaO will increase.
2) If the density of chloroform is 1.48 g/mL, what is the volume of 541 g of chloroform?
Answer:
V = 365.54 mL
Explanation:
Given that,
The density of chloroform, d = 1.48 g/mL
The mass of chloroform, m = 541 g
We need to find the volume of chloroform.
We know that,
Density = mass/volume
So,
[tex]V=\dfrac{m}{d}\\\\V=\dfrac{541\ g}{1.48\ g/mL}\\\\=365.54\ mL[/tex]
So, the volume of chloroform is 365.54 mL.
Kolbe's reaction with an example
Answer:
∵
Explanation:
Type the correct answer in the box.
Calculate the density of the substance.
A sample of a substance has a mass of 27.3 grams and a volume of 7.0 centimeters3. The density of this substance is ____
grams/centimeter3.
Answer:
3.9g/cm3
Explanation:
Density ( d)=?
Mass(m)=27.3g
Volume (v)=7.0cm3
D=m÷v
D=27.3g÷7.0cm3
D=3.9g/cm3
Project: Global Temperature Change
Research and write an essay about the rise of global temperatures over the past century.
PLEASE HELP THIS IS 10% OF MY GRADE
Answer:
Im sorry i cant write a whole essay right now but these sourcea could help.
https://climate.nasa.gov/effects/
https://www.climate.gov/news-features/understanding-climate/climate-change-global-temperature
Answer:
have you done it yet?
Explanation:
..
D. Write the name of the branched alkane next to the drawing of the molecule. (2 points)
Answer: hello your question lacks some data attached below is the missing data
answer :
a) 3-methyl heptane
b) 2-methyl pentane
c) 2-methyl heptane
d) 2-methyl hexane
e) 3-methyl hexane
Explanation:
we will select the longest carbon chain as the branched alkane and name it
a) 3-methyl heptane ( first diagram )
b) 2-methyl pentane ( second diagram )
c) 2-methyl heptane ( third diagram )
d) 2-methyl hexane ( fourth diagram )
e) 3-methyl hexane ( fifth diagram )
Note : sixth diagram = first diagram
ACTUAL YIELD VS THEORETICAL YIELD?
Actual yield over theoretical yield, then multiply by 100
Calculate [H3O+] and [OH−] for each of the following solutions at 25 ∘C given the pH.
pH= 11.22
Answer: The value of [tex][H_{3}O^{+}][/tex] is [tex]6.025 \times 10^{-12}[/tex] M and [tex][OH^{-}][/tex] is [tex]1 \times 10^{-14}[/tex].
Explanation:
pH is the negative logarithm of concentration of hydrogen ion.
It is given that pH is 11.22. So, the value of concentration of hydrogen ions is calculated as follows.
[tex]pH = - log [H^{+}]\\11.22 = - log [H^{+}]\\conc. H^{+} = 6.025 \times 10^{-12}[/tex] M
Let the value [tex]6.025 \times 10^{-12}[/tex] is considered as equal to 0. Hence, the relation between pH and pOH value is as follows.
pH + pOH = 14
0 + pOH = 14
pOH = 14
Now, pOH is the negative logarithm of concentration of hydroxide ions.
Hence, [tex][OH^{-}][/tex] is calculated as follows.
[tex]pOH = - log [OH^{-}]\\14 = - log [OH^{-}]\\conc. OH^{-} = 1 \times 10^{-14} M[/tex]
Thus, we can conclude that the value of [tex][H_{3}O^{+}][/tex] is [tex]6.025 \times 10^{-12}[/tex] M and [tex][OH^{-}][/tex] is [tex]1 \times 10^{-14}[/tex].
What mass of hydrochloric acid that reacted with zinc will produced 0.15dm3 of hydrogen at st.p? Equation for this reaction:
Zn + 2HCl ------> ZnCl2 + H2
Answer:
[tex]{ \tt{22.4 \: dm {}^{3} \: contains \: 1 \: mole \: of \: hydrogen }} \\ { \tt{0.15 \: {dm}^{3} \: will \: contain \: ( \frac{0.15}{22.4} \times 1) \: moles }} \\ = 0.0067 \: moles \\ { \bf{mole \: ratio = 1 :1 }} \\ { \tt{1 \: mole \: weighs \: 65.38 \: g}} \\ { \tt{0.0067 \: moles \: weighs \: (0.0067 \times 65.38) \: g}} \\ = 0.44 \: g[/tex]
What are some of the reasons why the United States did not adopt the metric system of measure?
at the time most of its trade was with France who did not use the metric system
the House of Representatives defeated the bill calling for conversion to metrics in 1974
the US was waiting for all other industrialized countries to adopt it before proceeding
at the time most of its trade was with England and Canada who did not use the metric system
Answer: in 1975, the United States passed the Metric Conversion Act. The legislation was meant to slowly transition its units of measurement from feet and pounds to meters and kilograms, bringing the US up to speed with the rest of the world. There was only one issue: the law was completely voluntary. Of course, that meant it pretty much never took off
Explanation:
they passed the metric act
For the neutralization reaction between pyridine and propanoic acid, draw curved arrows to indicate the direction of electron flow. Draw curved arrows to show the movement of electrons in this step of the mechanism.
Answer:
For the neutralization reaction between pyridine and propanoic acid, draw curved arrows to indicate the direction of electron flow.
Draw curved arrows to show the movement of electrons in this step of the mechanism.
Explanation:
According to Bronsted acid-base theory, an acid is a substance which is a proton donor.
Base is the proton acceptor.
In the given example, acid is propanoic acid and it loses the proton.
Pyridine is the base and it accepts the proton from propanoic acid.
The entire reaction is shown below:
Please help quick thanks
Answer:
Q = 6019J
Explanation:
Using the formula as follows:
Q = m × c × ∆T
Where;
c = specific heat capacity
Q = amount of heat (J)
m = mass of substance
∆T = change in temperature (°C)
According to the information given in this question,
m = 80g
c = 4.18 J/g°C
Initial temperature = 25°C
Final temperature = 43°C
∆T = 43°C - 25°C = 18°C
Q = 80 × 4.18 × 18
Q = 6019.2J
1. How many atoms of chlorine are present in 1.70x1023 molecules Cl2?
Explanation:
the answer is in the image above
using standard reduction potentials
Cr+3e = Cr -0.4 volt
Cl2+2e = 2Cl +1.36 volt
what the value of E for the cell with reaction
2Cr +3Cl2 = 3Cr +6Cl
Answer:
Hindi ko Po alam sorry po
A series of measurements in the lab led to an experimental result of 32.9 mL, with a calculated standard deviation of 0.3 mL. What is the standard way to report this result?
Answer: The standard way to report this result is [tex]32.9\pm 0.3 mL[/tex]
Explanation:
The standard method of representing a result is:
[tex]\text{Calculated value }\pm \text{ Standard deviation}[/tex]
The reporting of a result is done in correct significant figures.
We are given:
Calculated value = 32.9 mL
Standard deviation = 0.3 mL
Rule of significant figures applied when numbers are added or subtracted:
The number having less number of significant figures after the decimal point will determine the number of significant figures in the final answer.
Number of significant figures after the decimal point = 1
Hence, the standard way to report this result is [tex]32.9\pm 0.3 mL[/tex]
Kavitha was doing an experiment to find out the percentage of water absorbed by the soil. She observed that soil 'sample A' absorbed more water compared to soil 'sample B'. If soil sample B is loamy soil, sample A contains which type of soil ?
{Note :- this question contains 2 points so please type the answer in a " short answer " type question
Answer:
Clay soil
Explanation:
We were told in the question about two samples of soil A and B. Sample B was confirmed to be loamy soil but it was discovered that sample A absorbed more water than sample B.
We now have to think about the kind of soil that has the greatest ability to absorb water. That soil type is called clay soil.
Clay soils possess a large surface area which is responsible for its ability to absorb more water. Hence, clay soil has the greatest water holding capacity.
5. What, if anything, is wrong with the nuclear equation shown below?
O
179
179 W
+
e
Re
-1
75
74
O A. The daughter product has the wrong atomic number.
O B. The daughter product has the wrong mass number
O c. The particle labeled 'e should have an mass number of 1.
O D. There is nothing wrong with the equation.
Answer:
It is A, The daughter product has the wrong atomic number
Explanation:
Have trust, please i beg of you.
:) thank me later, love ya
The daughter's product has the wrong atomic number. Hence, option A is correct.
What is the nuclear equation?Nuclear equations represent the reactants and products in radioactive decay, nuclear fission, or nuclear fusion.
Beta decay - A common mode of radioactive decay in which a nucleus emits beta particles. The daughter nucleus will have a higher atomic number than the original nucleus.
Hence, the daughter's product has the wrong atomic number.
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Predict a likely mode of decay for each of the following unstable nuclides.
a. Ti-57
b. Zn-59
c. Ba-123
d. Cr-60
Answer:
D
Explanation:
D
The mode of decay for each of the following unstable nuclides are (a) ⁵⁷Ti is beta decay (b) ⁵⁹Zn is Positron emission (c) ¹²³Ba is Positron emission (d) ⁶⁰Cr is beta decay.
How to determine the mode of decay ?Change in mass/atomic number: if A decrease by 4 and Z decrease by 2 then the mode of decay is alpha decay.Change in mass/atomic number: if A unchanged and Z increase by 1 then the mode of decay is beta decay.Change in mass/atomic number: if A unchanged and Z is also unchanged then the mode of decay is gamma decay.Change in mass/atomic number: if A unchanged and Z decrease by 1 then the mode of decay is Positron emission.Change in mass/atomic number: if A unchanged and Z decrease by 1 then the mode of decay is Electron capture.Now lets predict the mode of decay for each of the following:
(a) Ti - 57
⁵⁷Ti₂₂ → ⁵⁷V₂₃ + ⁰e₋₁
Here A is unchanged and Z is increases by 1 so the mode of decay is beta decay.
(b) Zn - 59
⁵⁹Zn₃₀ → ⁵⁹Cu₂₉ + ⁰e₊₁
Here A is unchanged and Z is decreases by 1 so the mode of decay is Positron emission.
(c) Ba - 123
¹²³Ba₅₆ → ¹²³Cs₅₅ + ⁰e₊₁
Here A is unchanged and Z is decreases by 1 so the mode of decay is Positron emission.
(d) Cr -60
⁶⁰Cr₂₄ → ⁶⁰Mn₂₅ + ⁰e₋₁
Here A is unchanged and Z is increases by 1 so the mode of decay is beta decay.
Thus, from above conclusion we can say that (a) ⁵⁷Ti is beta decay (b) ⁵⁹Zn is Positron emission (c) ¹²³Ba is Positron emission (d) ⁶⁰Cr is beta decay.
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in a reaction 2Fe+Cl2→2FeCl2
Answer:
no equation
Explanation:
Please help me with question 7. Thank you so much.
Answer:
The system is not at equilibrium and the reaction will proceed to the left.
Explanation:
Step 1: Write the balanced equation
H₂(g) + CO₂(g) ⇄ CO(g) + H₂O(g)
Step 2: Calculate the reaction quotient (Q)
The reaction is calculated in the same way as the equilibrium constant (Kc) but it uses the concentrations at any time.
Q = [CO] × [H₂O] / [H₂] × [CO₂]
Q = 0.610 × 0.695 / 0.425 × 0.500 = 2.00
Since Q ≠ Kc, the reaction is not at equilibrium.
Since Q > Kc, the reaction will proceed to the left.
How many milliliters of a 0.40%(w/v) solution of nalorphine must be injected to obtain a dose of 1.5 mg?
Answer:
0.375mL of solution of nalorphine must be injected
Explanation:
A solution of 0.40% (w/v) contains 0.40g of solute (In this case, nalorphine), in 100mL of solution. To obtain 1.5mg of nalorphine = 1.5x10⁻³g of nalorphine are needed:
1.5x10⁻³g * (100mL / 0.40g) =
0.375mL of solution of nalorphine must be injected