Answer:
an if/then statement
Explanation:
The electronic arrangement of an atom shows how electrons are distributed across the different energy levels. Which of the following elements is represented by the electron arrangement 2, 8, 18, 6?
А Сa
B. Mg
C. S
D Se
E. Ga
Answer:
The answer is D which is Selenium
Please help answering 11)
Answer:
the answer is C
Explanation:
công thức phân tử của glucozo
C₆H₁₂O₆ is the molecular formula of gulcozo.
convert 36.52 mg to ?___ g
Answer:
0.0365 is your answer
Explanation:
hope it will help uAnswer:
365.2gㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤ
A sample of Kr gas is observed to effuse through a pourous barrier in 8.15 minutes. Under the same conditions, the same number of moles of an unknown gas requires 4.53 minutes to effuse through the same barrier. The molar mass of the unknown gas is ____________ g/mol.
Answer:
25.88 g/mol
Explanation:
Graham's law is a famous law which states that the diffusion rate or the effusion rate of any gas varies inversely to the square root of the molecular weight the gas.
So from Graham's law, we have,
[tex]$\frac{\text{time}}{M^{1/2}}=\text{constant}$[/tex]
Using the sample of Kr gas having M = 83.8
[tex]$\frac{8.15}{(83.8)^{0.5}}= \frac{4.53}{M^{0.5}}$[/tex]
[tex]$M^{0.5}= 5.088$[/tex]
M = 25.88 g/mol
Izopropanole doesn't form by Select one:
a. Reduction of propan-2-one
b. Hydration of 2-chloropropane
c. Hydration of propene
d. Reduction of propanal
Izopropanol doesn't form by Hydration of propene.
What is Reduction of propan-2-one?Acetone, propanone, or dimethyl ketone, exists as an organic compound with the formula (CH₃)₂CO. It stands for the simplest and smallest ketone. Reduction of ketones can be accomplished by hydrogenation (or) utilizing Grignard Reagent. Let us now decrease propanone to propan-2-ol by hydrogenation. The reduction of propane in the existence of catalyst platinum along with hydrogen provides the product propan-2-ol.
The correct answer is option A.
Izopropanol doesn't form by Hydration of propene.
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If the balance were not tared prior to weighing out the KHP.... how would you expect this to affect the molarity of NaOH calculated? What type of error is this?
Answer:
Following are the response to the given question:
Explanation:
In the given scenario, When the balance has never been tainted before the KHP is weighted, which can affect the molar concentration of NaOH because its molarity is directly proportional to the weight including its substance. In this question it is the mistake is systemic because it may be corrected by modifying balancing parameters.
Adding more than one equivalent of HCl to pent-1-yne will lead to which product:______.
a. 1,2-dichloro-1-butene.
b. 1,1-dichloropentane.
c. 2,2-dichloropentane.
d. 2,2-dichlorobutane.
Answer:
c. 2,2-dichloropentane.
Explanation:
Hello there!
In this case, according to the given information, it turns out possible for us to firstly draw the structure of the reactant, pent-1-yne:
[tex]CH\equiv C-CH_2-CH_2-CH_2[/tex]
Now, we infer the halogen is added to the carbon atom with the most carbon atoms next to it, in this case, carbon #2, in order to write the following product:
[tex]CH\equiv C-CH_2-CH_2-CH_2+2HCl\rightarrow CH_3- CCl_2-CH_2-CH_2-CH_2[/tex]
Whose name is 2,2-dichloropentane.
Regards!
How does the radiation from radioisotopes cause damage to human tissue?
Answers
A.
by ionization knocking electrons away from atoms
B.
by breaking the bonds between atoms in molecules
C.
by causing nuclear chain reactions inside cells
D.
by causing transmutations of atoms within cells
Answer:
Explanation:
B.
by breaking the bonds between atoms in molecules
Suppose you are studying the Ksp of CaCl2, which has a molar mass of 110.98 g/mol, at multiple temperatures. You dissolve 4.99 g of CaCl2 in 10.0 mL of water at 100 oC and cool the solution. At 90 oC, a solid begins to appear. What is the Ksp of CaCl2 at 90 oC
Answer:
Hence the Solubility product,
Ksp = [Ca2+] [Cl-]2
or, Ksp = (4.5) (9)2
or, Ksp = 364.5
Explanation:
Mass of CaCl2 = 4.99 g
Molar mass of CaCl2 = 110.98 g/mol
Moles of CaCl2
= given mass/ molar mass
= 4.99/ 110.98
= 0.045
Volume = 10.0 mL = 0.01 L
CaCl2 dissociates into its ion as:
CaCl2 (s) \rightleftharpoons Ca2+ (aq) + 2 Cl- (aq)
At 90°C, the solution is saturated with Ca2+ and Cl- ions.
Moles of Ca2+ = Moles of CaCl2 dissolved = 0.045
Moles of Cl- = 2 x ( Moles of CaCl2 dissolved) = 2 x 0.045 = 0.09
[Ca2+] = Moles/ Volume = 0.045/ 0.01 = 4.5 M
[Cl-] = 0.09/ 0.01 = 9 M
Solubility product,
Ksp = [Ca2+] [Cl-]2
or, Ksp = (4.5) (9)2
or, Ksp = 364.5
Which of the following behaviors would best describe someone who is listening and paying attention? a) Leaning toward the speaker O b) Interrupting the speaker to share their opinion c) Avoiding eye contact d) Asking questions to make sure they understand what's being said
Answer:
a Leaning towards the speaker
The sample concentration was measured at 50mg/ml. The loading concentration needs to be 10mg/ml. The final volume needs to be 25ul. What is the volume of sample needed and the amount of buffer needed to reach 25ul
Answer:
a) [tex]V_1=5ul[/tex]
b) [tex]v=20ul[/tex]
Explanation:
From the question we are told that:
initial Concentration [tex]C_1=50mg/ml[/tex]
Final Concentration [tex]C_2=10mg/ml[/tex]
Final volume needs [tex]V_2 =25ul[/tex]
Generally the equation for Volume is mathematically given by
[tex]C_1V_1=C_2V_2[/tex]
[tex]V_1=\frac{C_1V_1}{C_2}[/tex]
[tex]V_1=\frac{10*25}{50}[/tex]
[tex]V_1=5ul[/tex]
Therefore
The volume of buffer needed is
[tex]v=V_2-V_1\\\\v=25-5[/tex]
[tex]v=20ul[/tex]
Which statement best describes what happens during a chemical reaction?
A. Reactants change into products.
B. Reactants change into new reactants.
C. Products change into reactants.
D. Products change into new products.
Answer:
A. Reactants change into products
Which of the following is classified as paramagnetic?
1.NO(+)
2.Be2
3.B2(+)
4.+N2(+)
which of the followong would change the element represented in the electron module?
a. adding 1 proton
b. adding 1 electron
c. adding 1 neutron
d. removing the electron
Answer:
removing the electron.
The term that would change the element represented in the electron module is removing the electron. The correct option is d.
What are elements?Chemical elements are the elements that are represented in the periodic table. There are 118 chemical elements discovered and represented in the periodic table. There are many more to be discovered.
The model is of an element. Elements are made up of atoms, and atoms contain charged particles. Out of these particles, electrons are revolved around the nucleus, which determined the atomic number of the element, and different elements have different numbers of electrons.
Removing the electron from the element, will change the element or change its atomic number.
Thus, the correct option is d. removing the electron.
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ASSINGMENT Propane react with oxygen gas to form Carbondioxide and water a. If 2.8 mole of propone react with excess oxygen ges. how many grams of Carbondioxide will be form?
Answer:
Propane (C3H8) reacts with Oxygen gas to form Carbon Dioxide and water.
a. If 2.8 moles of Propane reacts with excess Oxygen gas how many grams of CO2 will be formed?
b. How many grams of Oxygen gas will completely react with 3.8 moles of Propane?
c. If 25 g of C3H8 reacts with excess Oxygen, how many moles of water will be formed?
d. If 38 g of water are produced in the reaction, how many moles of CO2 were produced?
Lead of mass 0.75kg is heated from 21°c to its melting point and continues to be heated unit it has all melted. Calculate how much energy is supplied to the lead. [Melting point of lead 372.5°c specific latent heat of fusion of lead = 23000 Jkg 'k ']
Answer:
65.5J
Explanation:
ML=Q
ML=MC(change in temperature)
0.75 X 23000 =0.75 X 351 X C
C= 65.5J
The energy supplied to the lead to melt from 21°c to its melting point is 51521 Joules.
What is the specific heat capacity?Specific heat is the amount of heat energy supplied to change the temperature of one unit mass of a substance by 1 °C. The SI unit of the specific heat capacity of a substance is J/Kg.
The mathematical expression for the specific heat capacity can be written as:
Q = mCΔT Where C is the specific heat of the substance.
The specific heat capacity depends upon the starting temperature and is an intensive characteristic of the material.
Given, the melting point of the lead T₂ = 327.5° C
The initial temperature of the lead, T₁ = 21° C
The latent heat of the lead given, L = 230000 J/Kg K
The specific heat of the lead, C = 130 J/Kg K
The heat required to melt the lead from 12°C to 327.5 °C is :
Q = m× [C × (T₂ - T₁) + L ]
Q = 0.75 × [0.130 (327.5 - 21) + 23000]
Q = 51521 J
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Which one of these four atoms has the most neutrons?
O A.
79
Se
34
B.
80
Br
35
OC.
73
Ge
32
84
Kr
36
O D.
Answer:
kr
Explanation:
it is radioactive so it loss electron due to which it jas most neutons
using the balanced equation below how many grams of lead(||) sulfate would be produced from the complete reaction of 23.6 g lead (|V) oxide
Answer:
59.8 g of PbSO₄.
Explanation:
The balanced equation for the reaction is given below:
Pb + PbO₂ + 2H₂SO₄ —> 2PbSO₄ + 2H₂O
Next, we shall determine the mass of PbO₂ that reacted and the mass of PbSO₄ produced from the balanced equation. This can be obtained as follow:
Molar mass of PbO₂ = 207 + (16×2)
= 207 + 32
= 239 g/mol
Mass of PbO₂ from the balanced equation = 1 × 239 = 239 g
Molar mass of PbSO₄ = 207 + 32 + (16×4)
= 207 + 32 + 64
= 303 g/mol
Mass of PbSO₄ from the balanced equation = 2 × 303 = 606 g
SUMMARY:
From the balanced equation above,
239 g of PbO₂ reacted to produce 606 g of PbSO₄.
Finally, we shall determine the mass of PbSO₄ that will be produced by the reaction of 23.6 g of PbO₂. This can be obtained as follow:
From the balanced equation above,
239 g of PbO₂ reacted to produce 606 g of PbSO₄.
Therefore, 23.6 g of PbO₂ will react to produce = (23.6 × 606) / 239 = 59.8 g of PbSO₄.
Thus, 59.8 g of PbSO₄ were obtained from the reaction.
What conversion factor would we need to convert moles of helium to atoms of helium?
Explanation:
The conversion factor required to convert moles of helium to atoms of helium is equal to 6.023*10²³ (NA). Helium is a monoatomic gas. Each molecule of helium gas contains one atom of helium. Therefore, one mole of helium gas will contain one mole atoms of helium.
You perform a distillation to separate a mixture of propylbenzene and cyclohexane, and you obtain 2.9949 grams of cyclohexane (density -0.779 g/mL, MW - 84.16 g/mol) and 1.6575 grams of propylbenzene (density = 0.862 g/mL, MW = 120.2 g/mol). What is the volume percent composition of cyclohexane in the mixture?
Answer:
66.67%
Explanation:
From the given information:
mass of cyclohexane = 2.9949 grams
density of cyclohexane = 0.779 g/mL
Recall that:
Density = mass/volume
∴
Volume = mass/density
So, the volume of cyclohexane = 2.9949 g/ 0.779 g/mL
= 3.8445 mL
Also,
mass of propylbenzene = 1.6575 grams
density of propylbenzene = 0.862 g/mL
Volume of propylbenzene = 1.6575 g/ 0.862 g/mL
= 1.9229 mL
The volume % composition of cyclohexane from the mixture is:
[tex]= (\dfrac{v_{cyclohexane}}{v_{cyclohexane}+v_{propylbenzene}})\times 100[/tex]
[tex]= (\dfrac{3.8445}{3.8445+1.9229})\times 100[/tex]
[tex]= (\dfrac{3.8445}{5.7674})\times 100[/tex]
= 66.67%
Choose the correct statement
a) The maximum value of principal quantum number (n) is 7
b) The angular quantum number (l) can receive value from 1 to (n-1)
c) The magnetic quantum number (ml) shows the energy of electron
d) The magnetic quantum number (ml) show how many orbitals in each subshell
Answer:
maybe number b is correct. ...thank you
P.1 is a variant of SARS-CoV2. This is the so-called "Brazil variant". It has the amino acid the substitution N501Y in the spike protein on the virus surface. In cellular fluids at ~pH 7 the wild type spike protein has a net negative charge. This substitution will make the spike protein
more negative
less hydrophobic
able to absorb move UV light
less negative
There are various variants of Cov id virus. The Brazilian variant P also known as Gamma variant is the third variant of the original SARS-CoV2.
The correct answer is more negative
This variant has raised concerns since it has ability to spread more quickly then previous variants and this is more negative variant.
It is assumed that Cov id variant Gamma and Delta has ability to absorb move UV light but this is not proved yet and research is underway.
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Hydrogen fluoride will react with glass (silicon dioxide. S_iO_2) according to the equation below What mass of HF is required to react completely with 16 0 g of glass? (Molar masses; Si 28 09 g/mol F 19 00 g/mol H. 1.01 g/mol O, 16.00 g/mol]
4HF(g) + SiO_2(s) --> SiF_4(g) + 2H_2O(g)
A. 5.33 g
B. 21.3 g
C. 64.0 g
D. 80.0 g
E. 320 g
Answer:
21.3 g. Option B
Explanation:
The reaction is:
4HF(g) + SiO₂(s) → SiF₄(g) + 2H₂O(g)
We analysed it and it is correctly balanced.
4 moles of hydrogen fluoride react to 1 mol of silicon dioxide in order to produce 1 mol of silicon fluoride and 2 moles of water vapor.
We determine molar mass of each reactant:
HF → 1.01 g/mol + 19 g/mol = 20.01 g/mol
SiO₂ → 16 g/mol . 2 + 28.09 g/mol = 60.09 g/mol
We convert mass to moles: 16 g . 1 mol /60.09g = 0.266 moles of glass
Ratio is 1:4. 1 mol of glass react to 4 moles of HF
Our 0.266 moles may react to (0.266 . 4) / 1 = 1.07 moles of gas
We convert moles to mass: 1.07 mol . 20.01 g/mol = 21.3 g
You are working in a lab when radiation alarms go off. You are able to hide inside a steel cabinet, whose sides are about 1.5 inches thick, until the alarm goes off. Preliminary reports show that the radiation was weakly ionizing and negatively charged. Were you safe in the cabinet?
A. Yes, it was beta radiation and the steel was enough to block it.
B. Yes, it was alpha radiation and not harmful.
C. No, it was beta radiation and very dangerous.
D. No, it was gamma radiation and can only be blocked by a thick wall of lead.
Answer
A
Explanation:
Beta radiation is only very dangerous when it is ingested or if there is nothing in the way. The steel should protect you.
Yes, it was beta radiation and the steel was enough to block it. Hence, option A is correct.
What is beta radiation?Beta radiation is a current of electrons released at a rate exceeding the speed of light, with kinetic energy between 0.2 MeV and 3.2 MeV. Due to their lower mass which is approximately 5.5×[tex]10^{-4}[/tex] amu (9.130×[tex]10^(-24)[/tex], interactions between β-particles and the atoms of pass-through materials are much less frequent than the interactions between 5-007-particles: less than 200 ion pairs are typically formed in each centimetre of the air passage.
When we are working in a lab when radiation alarms go off and we are able to hide inside a steel cabinet, whose sides are about 1.5 inches thick, until the alarm goes off.
Preliminary reports show that the radiation was weakly ionizing and negatively charged. Yes, it was beta radiation and the steel was enough to block it.
Hence, option A is correct.
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What mass of NaNO3 must be dissolved to make 838mL of a 1.25 M solution
Answer:
89.04 g of NaNO₃.
Explanation:
We'll begin by converting 838 mL to L. This can be obtained as follow:
1000 mL = 1 L
Therefore,
838 mL = 838 mL × 1 L / 1000 mL
838 mL = 0.838 L
Next, we shall determine the number of mole of NaNO₃ in the solution. This can be obtained as follow:
Volume = 0.838 L
Molarity = 1.25 M
Mole of NaNO₃ =?
Mole = Molarity × volume
Mole of NaNO₃ = 1.25 × 0.838
Mole of NaNO₃ = 1.0475 mole
Finally, we shall determine the mass of NaNO₃ needed to prepare the solution. This can be obtained as follow:
Mole of NaNO₃ = 1.0475 mole
Molar mass of NaNO₃ = 23 + 14 + (16×3)
= 23 + 14 + 48
= 85 g/mol
Mass of NaNO₃ =?
Mass = mole × molar mass
Mass of NaNO₃ = 1.0475 × 85
Mass of NaNO₃ = 89.04 g
Therefore, 89.04 g of NaNO₃ is needed to prepare the solution.
Spell out the full name of the compound.
Answer:
it is propane
C3H8 it is propane
The Full name of the given compound is Propane.
What is Propane ?Propane is a three-carbon alkane with the molecular formula C₃H₈.
It is a gas at standard temperature and pressure, but compressible to a transportable liquid.
In the figure given ;
Black balls represents Carbon atomsWhite balls represents Hydrogen atomsIn the given figure, there is single bond present between Carbon and Hydrogen. Hence, The Full name of the given compound is Propane.
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Standard hydrogen electrode acts as both anode and cathode.Explain.
Answer:
A Standard Hydrogen Electrode is an electrode that scientists use for reference on all half-cell potential reactions. The value of the standard electrode potential is zero, which forms the basis one needs to calculate cell potentials using different electrodes or different concentrations. It is important to have this common reference electrode, just as it is important for the International Bureau of Weights and Measures to keep a sealed piece of metal that is used to reference the S.I. Kilogram.
Answer:
The role of an electrode as cathode or anode depends on the nature and electrode potential of the other electrode with which it forms the complete electrochemical cell.
When a cell is to be made with zinc electrode and hydrogen electrode, the hydrogen electrode will behave as a cathode and the zinc electrode will behave as anode because zinc is present above hydrogen in the activity series. That is zinc is more electropositive than hydrogen.
If the cell is made with a copper electrode and hydrogen electrode, the hydrogen electrode will behave as anode and the copper electrode as a cathode. This is due to the fact that Cooper is present below hydrogen in the activity series. Copper is less electropositive than hydrogen.
Explanation:
An ordinary gasoline can measuring 30.0 cm by 20.0 cm by 15.0 cm is evacuated with a vacuum pump.
1a. Assuming that virtually all of the air can be removed from inside the can, and that atmospheric pressure is 14.7 psi, what is the total force (in pounds) on the surface of the can?
1b. Do you think that the can could withstand the force?
Answer:
Explanation:
From the given information:
The surface area of the can = (30 × 20 × 2) +(20× 15 × 2) +(30 × 15 × 2)
= 1200 + 600 + 900
= 2700 cm²
Since 1 inch² = 0.155 inch²
The surface area in inches² = 2700 × 0.155 inch²
= 418.5 inches²
The total force can be determined by using the expression:
Force = Pressure ×Area
Force = 14.7 psi × 418.5 inches²
Force = 6151.95 lbs
Yes, the gasoline can will be able to withstand the force.
does anyone know how to solve this and what the answer would be?
Dynamic equilibrium is showed at the point at which solid liquid and gas intersect.
At the point at which solid liquid and gas intersect represents a system that shows dynamic equilibrium. There is equal amount of reactants and products at the point of dynamic equilibrium because the transition of substances occur between the reactants and products at equal rates, means that there is no net change. Reactants and products are formed at the rate that no change occur in their concentration.
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