Answer:
42.5 mins
Explanation:
Given that for a first order reaction;
ln[A] = ln[A]o - kt
[A] = 0.1 M
[A]o = 0.2 M
t= 14.2 mins
ln0.1 = ln0.2 - 14.2t
ln0.1 - ln0.2/-14.2=k
k= -2.303 -(-1.609)/-14.2
k= 0.0489 min-1
So;
ln0.025 =ln0.2 - 0.0489t
ln0.025 - ln0.2/-0.0489 =t
t= -3.689 - (-1.609)/-0.0489
t= 42.5 mins
A certain shade of blue has a frequency of 7.28×1014 Hz.
What is the energy of exactly one photon of this light? Planck's constant is ℎ=6.626×10−34 J⋅s.
Explanation:
the enerfy of of one photon of this light is 4.85x10^-19 J
E= 6.63 x 10^-34 J/S x 7.32 x10^14 S ^-1E= 4.85x10^-19 J
The decomposition of hydrogen peroxide was studied, and the following data were obtained at a particular temperature.Time (s) [H2O2] (mol/L)0 1.00120 ± 1 0.91300 ± 1 0.78600 ± 1 0.591200 ± 1 0.371800 ± 1 0.222400 ± 1 0.133000 ± 1 0.0823600 ± 1 0.050 Assuming that the rate= -delta [H2O2]/delta t determine the rate law, integrated rate law, and the value of the rate constant. Calculate [H2O2] at 4000. s after the start of the reaction.
Answer:
Explanation:
From the graphical diagram attached below; we can see the relationship between the concentration of [tex]H_2O_2[/tex] which declines exponentially in relation to the time and it obeys the equation: [tex]\mathtt{y = 0.9951 e^{-8\times 10^{-4}x}}[/tex]
This relates to the 1st order reaction rate, whereby:
The integrated rate law[tex]\mathtt{ [A] = [A]_o e^{-kt}}[/tex]
here:
[A] = reactant concentration at time (t)
[A]_o = initial concentration for the reactant
k = rate constant
As such, the order of the reaction is the first order
Rate constant [tex]\mathtt{k = 8\times 10^{-4} {s^{-1}}}[/tex]
Rate law [tex]\mathtt{= k[H_2O_2]}[/tex]
The integrated rate law [tex]\mathtt{[H_2O_2] = [H_2O_2]_oe^{-(8*10^{-4})t}}[/tex]
From the given table:
the initial concentration of [tex]H_2O_2[/tex] = 1.00 M
∴
We can determine the concentration of the reactant at 4000s by using the formula:
[tex]\mathtt{[H_2O_2] = [H_2O_2]_oe^{-8*10^{-4}(t)}}[/tex]
[tex]\mathtt{[H_2O_2] = (1.00\ M)*e^{-8*10^{-4}(4000)\ s}}[/tex]
[tex]\mathtt{[H_2O_2] =0.0407 \ M}[/tex]
Finally, at 4000s: the average rate is:
[tex]\mathtt{= (8*10^{-4} \ s^{-1})(4000 \ s) }\\ \\ \mathtt{ = 3.256 \times 10^{-5} \ M/s}[/tex]
A sample of gas with an initial volume of 9.35 L at a pressure of 784 torr and a temperature of 295 K is compressed to a volume of 2.84 L and warmed to a temperature of 310 K. What is the final pressure of the gas in atmospheres (atm)?
a. 4.97 atm.
b. 0.113 atm.
c. 5.95 atm.
d. 7.03x10^3 atm.
Answer:
D
Explanation:
sound waves? like what they do.
Answer:
A sound wave is the pattern of disturbance caused by the movement of energy traveling through a medium (such as air, water, or any other liquid or solid matter) as it propagates away from the source of the sound. The source is some object that causes a vibration, such as a ringing telephone, or a person's vocal chords.
HEY. HOPE THIS HELPS♡
Consider the reaction of Copper with Sulfur: Cu +S → Cus. Using the
below data, which of following is true?
A. Sulfur was the limiting reactant; 1.61 g of sulfur were reacted.
B. Copper was the limiting reactant; 1.32 g of sulfur were unreacted
C. Copper (II) sulfide was the limiting reactant; 4.78 g was formed.
D. There was no limiting reactant; both reactants remained in excess.
Answer:
B. Copper was the limiting reactant; 1.32 g of sulfur were unreacted
Explanation:
Cu + S → CuS
As there was no Cu left after the reaction was completed, Cu was not the reactant in excess but rather the limiting reactant.Copper (II) sulfide (CuS) cannot be the limiting reactant, because it is not a reactant but a product.With the two points above in mind, the only option left is B.
20)
Which substance is an acid?
A)
Ba(OH)2
B)
CH3COOCH3
C)
H3PO4
D)
NaCl
help
Answer:
C.
Explanation:
Also, please help me in my questions tab if you can! Thank you so much
A 1.375 g sample of mannitol, a sugar found in seaweed, is burned completely in oxygen to give 1.993 g of carbon dioxide and 0.9519 g of water. The empirical formula of mannitol is
Answer:
[tex]C_3H_7O_3[/tex]
Explanation:
Hello there!
In this case, according to the given information, it turns out possible for us to infer that the empirical formula of mannitol contains carbon, hydrogen and oxygen, so that the first step is to calculate the moles of C and H contained in the CO2 and H2O, respectively, as the only sources of these two elements in the formula:
[tex]n_C=1.993gCO_2*\frac{1molCO_2}{44.01gCO_2}*\frac{1molC}{1molCO_2} =0.0453molC\\\\n_H=0.9519gH_2O*\frac{1molH_2O}{18.02gH_2O}*\frac{2molH}{1molH_2O} =0.106molH[/tex]
Next, we calculate the grams and moles of O by subtracting the mass of C and H from the mass of the sample:
[tex]m_O=1.375g-0.0453molC*\frac{12gC}{1molC}-0.106molH*\frac{1.01gH}{1molH}=0.724gO\\\\n_O=0.724gO*\frac{1molO}{16.0gO} =0.0453molO[/tex]
Finally, we divide the moles of C, H and O by 0.0453 as the fewest moles of both C and O to find the mole ratios in the formula:
[tex]C:\frac{0.0453mol}{0.0453mol} =1\\\\H:\frac{0.106mol}{0.0453mol} =2.34\\\\O:\frac{0.0453mol}{0.0453mol} =1[/tex]
To get:
[tex]CH_{2.34}O[/tex]
Which must be multiplied by 3 to get whole numbers for all the subscripts, and therefore obtain:
[tex]C_3H_7O_3[/tex]
Regards!
The largest number of stable nuclei have an ________ number of protons and an ________ number of neutrons.
Answer:
did it give you answers to in blanks
3. How many electrons are in the M shell?
Answer:
i believe the answer is D: 18
Explanation:
Answer:
18
M shell can actually hold 18 electron as you move higher atomic number
Plss help me solve question 7
Thank you.
Answer:
4- ethyl- 6-methylocta- 1,2,5- triene
Explanation:
See attached. Please give me brainliest I worked hard. ;(
A 115-g sample of steam at 100 °C is emitted from a volcano. It condenses, cools, and falls as snow at 0.0 °C. How many kilojoules were released?
Can someone please tell me how to do it step by step?
Answer:
∑Q(TTL) = 347 Kj. = 82.8 Kcal. (3 sig. figs.)
Explanation:
Draw a typical heating curve for water (see figure below) and label each section with data needed to calculate the amount of heat flow in the specified section.
Super-imposing given data onto a trace of a typical heat flow chart for water finds there are three segments of the heating curve that can utilize the given data to calculate heat flow for each segment. With all three heat flow quantities, the total heat quantity associated with this problem is marked in orange. Calculate the heat quantity associated with the designated segments and add to obtain total heat flow for the transitions listed.
Point E to D => Q₄ = m∙ΔHᵥ = (115g)(540 cal/g) = 62,100 cals.
Point D to C => Q₃ = m∙c∙ΔT = (115g)(1 cal/g∙˚C)(100˚C) = 11,500 cals.
Point C to B => Q₂ = m∙ΔHₓ = (115g)(80cal/g) = 9,200 cals.
Total Heat Flow (∑Qₙ) = Q₄ + Q₃ + Q₂ = 62,100 cals. + 11,500 cals. + 9,200 cals. = 82,800 cals.
= (82,800 cals.)(4.184 joules/cal.) = 346,435 joules = 346.435 Kj ~ 347 Kj (3 sig. figs.) _____________________________________________________
m = mass = 115g
c = specific heat of liquid water = 1 calorie/gram·°C = 4.184 j/g·°C
ΔT = temperature change in degrees Celsius
ΔHᵥ = heat of vaporization = 540 cals./gram
ΔHₓ = heat of crystallization = 80 cal./gram
Qₙ = heat flow quantity per specific segment (calories or joules)
∑Qₙ = total heat flow
Heating curve for water:
Note in the diagram that only two formulas are used.
Q = m·c·ΔT => heating or cooling the pure condensed state. The segments demonstrate temperature change.
Q = m·ΔHₙ => heat flow during phase change. Note, in these segments of the heating curve two phases are in contact. That is solid/liquid or liquid/gas phase substances. Also note, in these segments, when two phases are in contact no temperature change occurs. Examples, ice water remains at a constant temperature until all ice is melted or all of the liquid water is frozen depending upon the direction of heat flow. The same is true for boiling water in that when two phases are in contact (liquid/gas), temperature remains constant. The portions of the heating curve designating phase transitions are horizontal and are defined by the equation Q = m·ΔH, while the curve segments that are only one phase demonstrate temperature change and are defined by the equation containing temperature change, Q = m·c·ΔT.
The total energy released during this whole process was 346.4 kiloJoules.
Explanation:
Given:
115 g of steam at 100°C condenses, cools, and falls as snow at 0.0°C.
To find:
The energy released during this whole process.
Solution:
In the given three stages will appear:
[tex]H_2O(g)\rightarrow H_2O(l) (at 100^oC)[/tex] [tex]H_2O(l)(at 100^oC)\rightarrow H_2O(l) (at 0.0^oC)[/tex][tex]H_2O(l)(at 0.0^oC)\rightarrow H_2O(s) (at 0.0^oC)[/tex]1) [tex]H_2O(g)\rightarrow H_2O(l) (at 100^oC)[/tex]
Phase change will occur at 100°C, that is from gas to liquid.
Energy released during the phase change of water from gas to liquid =[tex]Q_1[/tex]
Latent heat of vaporization of water =[tex]\Delta H_{vap}=2.260 kJ/g[/tex]
Latent heat of condensation of water =[tex]\Delta H_{con}=- \Delta H_{vap}=2.260 kJ/g=-2.260 kJ/g[/tex]
Mass of steam = 115 g
[tex]Q_1=115 g\times \Delta H_{con}\\=115g\times -2.260 kJ/g=-259.9 kJ[/tex]
2) [tex]H_2O(l)(at 100^oC)\rightarrow H_2O(l) (at 0.0^oC)[/tex]
Mass of water = m = 115 g ( steam converted into water)
Initial temperature of water = [tex]T_i=100^oC[/tex]
Final temperature of water =[tex]T_f=0.0^oC[/tex]
The specific heat of water = c = 8.186J/g°C
Energy released during this stage = [tex]Q_2[/tex]
[tex]Q_2=m\times c\times (T_f-T_i)\\=115g\times 4.186 J/g^oC\times (0.0^oC-100^oC)\\=-48,139 J= -48.139 kJ\\(1 J=0.001kJ)[/tex]
3)[tex]H_2O(l)(at 0.0^oC)\rightarrow H_2O(s) (at 0.0^oC)[/tex]
Water freezes at 0°C ,phase change will occur at 0.0°C, that is from liquid to solid.
Energy released during the phase change of water from liquid to solid=[tex]Q_3[/tex]
Latent heat of fusion of water =[tex]\Delta H_{fus}=-334J/g[/tex]
Mass of water = 115 g
Energy released during this stage:
[tex]Q_3=115g\times \Delta H_{fus}\\115\times -334 J/g=-38,410 J\\=-38,410 J=-38.410 kJ\\(1 J=0.001kJ)[/tex]
Total energy released during this whole process = Q
[tex]Q = Q_1+Q_2+Q_3\\Q=(-259.9 kJ)+( -48.139 kJ)+(-38.410 kJ)\\=-346.449 kJ\approx -346.4 kJ[/tex]
(negative sign indicates that heat energy is released))
The total energy released during this whole process was 346.4 kiloJoules.
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g a commercial product for treating injuries contains 35.0 g of MgSO4 in one bag and 250 mL of water in a seperate bag. When the bags are broken and their contents mixed, the temperature of the system changes. Calculate this temperature change
Answer:
he a real G
Explanation:
og tripple og
P4 + NaOH + H2O——> PH3 + Na2HPO3
Balance given equation by oxidation no. Method
Answer:
P4 + 4NaOH + 2H2O → 2PH3 + 2Na2HPO3
Explanation:
A chemical equation is said to be balanced if the quantity of each type of atom in the reaction is the same on both the reactant and product sides. In a balanced chemical equation, the mass and the charge are both equal.
A chemical equation must balance according to the rule of conservation of mass. According to the rule, mass cannot be generated or removed during a chemical process.
Chemical equations must be balanced, which means that the atom types and numbers on both sides of the reaction arrow must match. Coefficients are the values added in front of formulas to balance equations; they multiply each atom in a formula.
Here the given equation is balanced as:
P₄ + 4NaOH + 2H₂O——> 2PH₃ + 2Na₂HPO₃
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the mass of a single potassium atom is 6.50×10-23 grams. How many potassium atoms would there be in 114 milligrams of potassium?
Answer:LOL
42
Explanation:
The mass of a single potassium atom is 6.50×10⁻²³ grams potassium atoms would be in 114 milligrams of potassium 17.53 ×10⁻²³.
What is an atom?
An atom is the most diminutive form of any chemical compound that takes part in the chemical reaction to form any product and it is equal to the one mole which is 2.303 ×10²³ moles of the Avogadros number.
To calculate the number of atoms we have, 6.50×10⁻²³ grams of potassium and the value of one particle is 2.303 ×10²³ moles,
atoms = 6.50×10⁻²³ / 114 milligrams of potassium
atoms of potassium = 17.53 ×10⁻²³. atoms.
Therefore, 17.53 ×10⁻²³.atoms are present if the mass of a single potassium atom is 6.50×10⁻²³ grams potassium atoms would there be in 114 milligrams of potassium.
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given two equations representing reactions: which type of reaction is represented by each of these equations?
Answer:
Equation 1 - nuclear fission
Equation 2 - nuclear fusion
Explanation:
Nuclear fission is a reaction in which a large nucleus is split into smaller nuclei when it is bombarded by neutrons. The process produces more neutrons to continue the chain reaction. This is clearly depicted in equation 1 as shown in the question.
Nuclear fusion is a reaction in which two light nuclei combine in order to form a larger nuclei. This is clearly depicted in equation 2 as shown in the question.
In the first reaction, a neutron is released, and in the second a helium atom is released. The given two equations represent nuclear fission and fusion.
What are nuclear reactions?A nuclear reaction is a reaction that involves the nuclei of the atom and the absorption and release of energy. In the first reaction, a big nucleus is split by the neutron bombardment into smaller nuclei.
In the second reaction the process of nuclear fusion, two nuclei combine into a single larger nucleus that is shown as:
₁¹H+ ²₁H → ³₂He
Therefore, nuclear fission and fusion are represented by each of these equations.
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Question on the image
Answer: The mass of carbon dioxide required is 308 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)
Given mass of octane = 100.0 g
Molar mass of octane = 114.23 g/mol
Putting values in equation 1, we get:
[tex]\text{Moles of octane}=\frac{100.0g}{114.23g/mol}=0.875mol[/tex]
For the given chemical reaction:
[tex]2C_8H_{18}+25O_2\rightarrow 16CO_2+18H_2O[/tex]
By the stoichiometry of the reaction:
2 moles of octane produces 16 moles of carbon dioxide
So, 0.875 moles of octane will produce = [tex]\frac{16}{2}\times 0.875=7mol[/tex] of carbon dioxide
Molar mass of carbon dioxide = 44 g/mol
Plugging values in equation 1:
[tex]\text{Mass of carbon dioxide}=(7mol\times 44g/mol)=308g[/tex]
Hence, the mass of carbon dioxide required is 308 g
Describe uses of H2S as analytical regent
Answer:
Hydrogen sulfide is used primarily to produce sulfuric acid and sulfur. It is also used to create a variety of inorganic sulfides used to create pesticides, leather, dyes, and pharmaceuticals. Hydrogen sulfide is used to produce heavy water for nuclear power plants (like CANDU reactors specifically).
Explanation:
Sana Po it's help
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Name the following alkane molecule:
Answer:
5–bromo–9–chlorodecane
Explanation:
To name the compound given above, the following must be obtained:
1. The longest continuous carbon chain. This gives the parent name of the compound.
2. The substituent group attached to the compound.
3. Position of the substituent group.
4. Combine the above to obtain the name.
Now, we shall determine the name of the compound as follow:
1. The longest continuous carbon chain is 10. Thus, the parent name of the compound is decane.
2. The substituent groups attached to the compound are:
I. Bromine (Br) => Bromo
II. Chlorine (Cl) => Chloro
3. The position of the substituent groups are:
I. Br => carbon 5
II. Cl => carbon 9
NOTE: numbering is done alphabetically.
4. Therefore, the name of the compound is:
5–bromo–9–chlorodecane
Answer:
A.
Explanation:
I chose this answer and it was correct ♀️
What is the volume of alcohol present in 200.0 mL of a 55\%(v/v) solution of alcohol ?
Answer:
110 mL
Explanation:
Equation for % v/v (volume concentration) is:
volume concentration = volume of solute / volume of solution
[tex]55\% v/v = v_{solute} /200\\v_{solute} =200 \times 55\%\\v_{solute} =110[/tex]
Beer's Law states that A=ebc, where A is the absorbance, ε is the molar absorptivity of the solute, b is the path length, and c is the concentration. Identify the experimental evidence from the activity that you have for the dependence of absorbance on each variable
The evidence for the dependence of absorbance on the variable ε is:_________
a. increasing the cuvette width increases the absorbance.
b. changing the compound changes the absorbance behavior.
c. adding more water decreases the absorbance.
Answer:
b. changing the compound changes the absorbance behavior.
Explanation:
Option a) would be akin to modifying the path length, b.Option b) would involve using a different solute, as such, there would be another molar absortivity, ε.Option c) would decrease the concentration (c) of the solute, which would explain why the absorbance would decrease as well.Draw the structural formula for both of these alcohols:
2,3, 4-trimethyl, 3-heptanol
4-ethyl, 4-octanol
Answer:
Check the image above
explanation:
When naming organic compounds based on IUPAC; we take note of functional group, position of functional group.
In 2,3,4-trimethyl-3-heptanol, the functional group is hydroxyl group ( OH ). It is on position 3 (2,3,4-trimethyl-3-heptanol. Then we put it on the third carbon. Another functional group is methyl group, with three positions, 2, 3, and 4.
In 4-ethyl-4-octanol, the functional group is hydroxyl group ( OH ) which is in position 4 on the fourth carbon. Another functional group is ethyl group in position 4 on the fourth carbon. In this case, the functional groups that have same position, are put on that same carbon.
What was one idea Dalton taught about atoms?
Explanation:
All atoms of one type were identical in mass and properties.
Write the precipitation reaction for cobalt(II) hydroxide in aqueous solution: Be sure to specify the state of each reactant and product.
Answer:
The equation for the precipitation reaction of cobalt (ii) hydroxide is given below:
CoSO₄ (aq) + NaOH (aq) ----> Co(OH)₂ (s) + Na₂SO₄ (aq)
Explanation:
Cobalt (ii) hydroxide is an inorganic compound consisting of cobalt (ii) ions, Co²+ and hydroxide ions, OH-. It is insoluble in water and the pure form known as the beta form is a pink-coloured solid. The impure form which incorporates other anions in its molecular structure is blue in colour and is ustable.
Cobalt (ii) hydroxide is formed as precipitate when an alkaline metallic hydroxide such as sodium hydroxide is mixed with an aqueous cobalt (ii) salt such as cobalt (ii) sulfate. The equation for the precipitation reaction of cobalt (ii) hydroxide is given below:
CoSO₄ (aq) + NaOH (aq) ----> Co(OH)₂ (s) + Na₂SO₄ (aq)
Being a basic hydroxide, cobalt (ii) hydroxide neutralizes acids to form cobalt (ii) salts and water. For example: Co(OH)₂ (s) + H₂SO₄ (aq) ---> CoSO₄ (aq) + H₂O
Thus, cobalt (ii) hydroxide is soluble in acids.
Cobalt(II) hydroxide is used mostly as a drying agent for paints, varnishes, and inks. It is also useful in the preparation of other cobalt compounds.
Phosphorus trichloride can be made by the following reaction: P4(s) 6Cl2(g) - 4) 4PCl3(l) What is the maximum amount of phosphorus trichloride that can be formed if 15 molecules of P4 are mixed with 42 molecules of chlorine
Answer:
48 molecules
Explanation:
From the given reaction:
[tex]\mathtt{P_4 + 6Cl_2\to 4PCl_3}[/tex]
i.e. 1 mole of Phosphorus react 6 moles of chlorine to yield 4 moles of PCl₃
This implies that for each P₄ molecule, we will require 6 molecules of Cl₂
We are provided with 15 molecules of P₄ and 42 molecules of Cl₂
Suppose we utilized the whole 15 molecules of P₄, we will require:
= 15 × 6 = 90 moles of Cl₂ which is not readily available except 42 are available.
If we utilized 42 molecules of Cl₂, we will require 42/6 = 7 molecules of P₄ which is readily available.
From this analysis, we can opine that Cl₂ serves as the limiting agent
∴
P₄ : Cl₂ : PCl₃ = 1 : 6 : 4 = 7 : 42 : 48
It implies that only 48 molecules of phosphorus trichloride will be formed.
Electrons are in ___________ ___________ surrounding the nucleus.
Answer:
electron shells
Explanation:
Eletrons are on the outeermost part of the atom called electron shells.
Using the periodic table,
choose the more reactive nonmetal. Br or as
Answer:
Br
Explanation:
because bromine is more reactive as reactivity increases on moving from left to right in p-block. hope this make sense :)
In the picture this is my last question pls.
Answer:
Chromosomes and I think its too many
Explanation:
how many s electrons are there in potassium?
Answer: 19
Explanation:
In order to write the Potassium electron configuration we first need to know the number of electrons for the K atom (there are 19 electrons). When we write the configuration we'll put all 19 electrons in orbitals around the nucleus of the Potassium atom.
Which of these is NOT a characteristics of minerals?
A) organic
B) inorganic
C) crystalline structure
D) definite chemical composition
Answer:a) organic
Explanation:
The shielding of electrons gives rise to an effective nuclear charge, Zeff, which explains why boron is larger than oxygen. Estimate the approximate Zeff felt by a valence electron of boron and oxygen, respectively.
a. +5 and +8.
b. +3 and +6.
c. +5 and +6.
d. +3 and +8.
e. +1 and +4.
Answer:
b. +3 and +6.
Explanation:
Zeff = Z - S
The Z denotes the no of protons i.e. atomic number
S denotes the non-valence electrons
For boron,
the electronic configuration is 1s₂ 2s₂ 2p₄
Now
Z = 5, S = 2
So,
Zeff = 5-2
= +3
For O, the electronic configuration is 1s₂ 2s₂ 2p₄
So,
Z = 8, S = 2
= 8-2
= +6
Hence, the second option is correct
