Answer:
The correct answer is -0.129 kJ
Explanation:
In the given case, the cooling of the balloon is done by withdrawing 0.784 J of heat, and the work done by the atmosphere on the balloon is 655 J. First, there is a need to transform kJ into J, 1 kJ = 1000 J. So, 0.784 kJ would be 784 J.
The ΔE or the change in the internal energy can be calculated by using the formula, ΔE = q + w ----- (1).
In the given case, q refers to the heat moved out of the system, that is, the value of q would be less than 0 or will be a negative quantity. Therefore, the heat moved out of the system will be -784 J. On the other hand, as the work or w is done on the system, therefore, the value of w would be more than 0 or will be a positive quantity. Thus, the value of w will be +655 J.
Now putting the values in the equation (1) we get,
ΔE = -784 J + 655 J
ΔE = -129 J or -0.129 kJ
As the change in internal energy comes out to be a negative value, therefore, the process is considered exothermic.
According to the Clausius theorem, the cyclic integral of
for a reversible cycle is zero.
Answer:
Yes it is true
Explanation:
This is because the Clausius theorem states that The cyclic integral always has two defined results. The results include it being less than or equal to zero under certain conditions.
When the system consists of only reversible processes, the cyclic integral is equal to zero. If it consists of and irreversible processes, the integral is usually less than zero.
The correct name for CaH2 is
Answer:
Calcium hydride
Explanation:
A booth renter is responsible for conducting all necessary business blank
Answer:
building and managing their own clients, purchasing supplies and keeping records
hope this helps you
chemical reactions occur in predictable ways
Answer:
Yes that is why you can even see how some chemicals might react but that is if you are not considering temperature, pressure, or if catalyst are involved.
Calculate the free energy change for the reaction:
2 NO(g) + O2(g) → 2 NO2(g)
(A) - 9.3 kcal
(B) + 24.9 kcal
(C) + 9.3 kcal
(D) - 16.6 kcal
(E) + 16.6 kcal
Answer:
(D) - 16.6 kcal
Explanation:
Hello,
In this case, the Gibbs free energy for the given reaction is computed in terms of the Gibbs free energy of formation of each species involved in the chemical reaction:
[tex]\Delta _rG=2\Delta _fG_{NO_2}-2\Delta _fG_{NO}-\Delta _fG_{O_2}[/tex]
Thus, it is found for nitrogen monoxide, oxygen and nitrogen dioxide the following Gibbs free energies of formation: 87.6, 0 and 51.3 kJ/mol respectively, therefore we compute:
[tex]\Delta _rG=2(51.3kJ/mol)-2(87.6kJ/mol)=-72.6kJ*\frac{1kcal}{4.184kJ} \\\\\Delta _rG=-17.35kcal[/tex]
The closest result is (D) - 16.6 kcal, as such difference is noticed when different sources for thermochemical data are used, in this case, the NIST data were used.
Best regards.
What is economic racism?
OA. Something that causes financial inequality for certain ethnic groups
OB. A stock market crash
OC. Laws and policies that go against a particular race
OD. All of the above
Please
Answer:
A
Explanation:
Calculate the molar solubility of CaCO3 in 0.250M Na2CO3
Kps CaCO3 is 4.96x10-9
Answer:
solubility is 1.984x10⁻⁹M
Explanation:
When CaCO₃ is in water, the equilibrium that occurs is:
CaCO₃(s) ⇄ Ca²⁺(aq) + CO₃²⁻(aq)
Kps = [Ca²⁺] [CO₃²⁻] = 4.96x10⁻⁹
If you have a 0.250M solution of Na₂CO₃, [CO₃²⁻] = 0.250M:
[Ca²⁺] [0.250M] = 4.96x10⁻⁹
Assuming you are adding an amount of CaCO₃:
[X] [0.250 + X] = 4.96x10⁻⁹
Where X is the amoun of CaCO₃ you can add, that means, solubility
X² + 0.250X - 4.96x10⁻⁹ = 0
Solving for X:
X = -0.25M → False answer, there is no negative concentrations.
X = 1.984x10⁻⁹M.
That means, solubility is 1.984x10⁻⁹M
Answer:
[tex]1.984x10^{-8}M[/tex]
Explanation:
Hello,
In this case, the equilibrium reaction for the solubility of calcium carbonate is:
[tex]CaCO_3(s) \rightleftharpoons Ca^{2+}(aq)+CO_3^{-2}(aq)[/tex]
In such a way, since 0.250 M sodium carbonate solution is the solvent, we assume an initial concentration of carbonate anion to be also 0.250 M since sodium carbonate is completely dissolved, for that reason the equilibrium equation turns out:
[tex]Ksp=[Ca^{2+}][CO_3^{2-}]\\\\4.96x10^{-9}=x*(0.250+x)[/tex]
Hence, solving for [tex]x[/tex] we have:
[tex]x=1.984x10^{-8}M[/tex]
Which corresponds to the molar solubility if calcium carbonate as well.
Regards.
Which of the following processes is endothermic? Group of answer choices the reaction associated with the ionization energy of lithium. the formation of CO2 from its elements in their standard states. the reaction associated with the heat of formation of Sr S. the reaction associated with the lattice energy of Na Br.
Answer:
the reaction associated with the ionization energy of lithium
Explanation:
An endothermic process is any process which requires or absorbs energy from its surroundings, usually in the form of heat.
the reaction associated with the ionization energy of lithium:
Ionization energy is endothermic because it requires an energy input to occur, we need to supply energy to remove that outermost electron.
the formation of CO2 from its elements in their standard states:
This reaction is exothermic, heat is released per mole of CO2 formed.
the reaction associated with the heat of formation of Sr S:
Heat is giving off, so the process is an exothermic process.
the reaction associated with the lattice energy of Na Br:
Lattice energy is exothermic. Lattice energy is the energy released when gaseous cations and anions associate with each other to form a solid.
. In which reaction is nitric acid acting as an oxidising agent?
A. CuO + 2HNO3 → Cu(NO3)2 + H2O
B. Cu + 4HNO3 → Cu(NO3)2 + 2H2O + 2NO2
C. Na2CO3 + 2HNO3 → 2NaNO3 + H2O + CO2
D. NaOH + HNO3 → NaNO3 + H2O. In which reaction is nitric acid acting as an oxidising agent?
A. CuO + 2HNO3 → Cu(NO3)2 + H2O
B. Cu + 4HNO3 → Cu(NO3)2 + 2H2O + 2NO2
C. Na2CO3 + 2HNO3 → 2NaNO3 + H2O + CO2
D. NaOH + HNO3 → NaNO3 + H2O
Answer:
B. Cu + 4HNO3 → Cu(NO3)2 + 2H2O + 2NO2
Explanation:
Hello,
In this case, we should understand oxidizing agents as those substances able to increase the oxidation state of another substance, therefore, in B. reaction we notice that copper oxidation state at the beginning is zero (no bonds are formed) and once it reacts with nitric acid, its oxidation states raises to +2 in copper (II) nitrate, thus, in B. Cu + 4HNO3 → Cu(NO3)2 + 2H2O + 2NO2 nitritc acid is acting as the oxidizing agent.
Moreover, in the other reactions, copper (A.), sodium (C. and D.) remain with the same initial oxidation state, +2 and +1 respectively.
Regards.
Answer:
B. Cu + 4HNO3 → Cu(NO3)2 + 2H2O + 2NO2
Explanation:
A substance is acting as oxidising agent when is reducing its chemical state in the reaction.
In HNO3, Nitrogen has an oxidation state of +5 (Each oxygen is -2, 3 oxygens, -6, 1 hydrogen, +1). Thus, if the oxidation state of the nitrogen in the products is < +5, the nitrogen is reducing its oxidation state acting as oxidising agent.
In the reactions:
A. CuO + 2HNO3 → Cu(NO3)2 + H2O . In Cu(NO₃)₂, Nitrogen has an oxidation state of +5. Thus, nitric acid is not acting as oxidising agent.
B. Cu + 4HNO3 → Cu(NO3)2 + 2H2O + 2NO2 . Also, oxidation state in Cu(NO₃)₂ does not have any change but there is another product, NO₂, where nitrogen has an oxidation state of +4. That means nitric acid is acting as oxidising agent.
C. Na2CO3 + 2HNO3 → 2NaNO3 + H2O + CO2 . Here, in NaNO₃, oxidation state of nitrogen is +5 (Na: +1, 3 O: -6). Thus, nitrogen is not changing is oxidation state and nitric acid is not acting as oxidising agent.
D. NaOH + HNO3 → NaNO3 + H2O. Here, also, the product is NaNO₃. That means nitric acid is not acting as oxidising agent.
What would be the volume of a balloon containing 64g of oxygen gas at STP (standard temperature and pressure)? You should be able to obtain this answer by calculation or by using logical reasoning.
Answer: 44.8 L
Explanation:
To find the volume, we would need to use the ideal gas law.
Ideal Gas Law: PV=nRT
We take the given information and plug it into the equation, but first, we have to manipulate the equation so that we are finding volume.
[tex]V=\frac{nRT}{P}[/tex]
P= 1.00 atm (STP)
T= 273.15 K (STP)
R= 0.08206 Latm/Kmol
n= [tex]64g*\frac{1mol}{31.998 g O_{2} }=2 mol[/tex]
[tex]V=\frac{(2 mol)(0.08206Latm/Kmol)(273.15 K)}{1.00atm} =44.8 L[/tex]
How many moles of HCl can be produced from 0.226 g of SOCl2? SOCl2 + H2O ----> SO2 + 2HCl
Explanation would be helpful c:
Answer:
3.80*10⁻³ moles of HCl can be produced from 0.226 g of SOCl₂
Explanation:
The balanced reaction is:
SOCl₂ + H₂O ----> SO₂ + 2 HCl
By stoichiometry of the reaction they react and produce:
SOCl₂: 1 moleH₂O: 1 moleSO₂: 1 moleHCl: 2 moleBeing:
S: 32 g/moleO: 16 g/moleCl: 35.45 g/moleH: 1 g/molethe molar mass of the compounds participating in the reaction is:
SOCl₂: 32 g/mole + 16 g/mole + 2*35.45 g/mole= 118.9 g/moleH₂O: 2*1 g/mole + 16 g/mole= 18 g/moleSO₂: 32 g/mole + 2*16 g/mole= 64 g/moleHCl: 1 g/mole + 35.45 g/mole= 36.45 g/moleThen, by stoichiometry of the reaction, the following amounts of mass react and are produced:
SOCl₂: 1 mole* 118.9 g/mole= 118.9 gH₂O: 1 mole* 18 g/mole= 18 gSO₂: 1 mole* 64 g/mole= 64 gHCl: 2 mole* 36.45 g/mole= 72.9 gThen the following rule of three can be applied: if by stoichiometry of the reaction 118.9 grams of SOCl₂ produce 2 moles of HCl, 0.226 grams of SOCl₂ how many moles of HCl do they produce?
[tex]moles of HCl=\frac{0.226 grams of SOCl_{2}*2 mole of HCl }{118.9 grams of SOCl_{2} }[/tex]
moles of HCl= 3.80*10⁻³
3.80*10⁻³ moles of HCl can be produced from 0.226 g of SOCl₂
How many moles are in 50 grams of cobalt?
help asapp
hey there!
atomic mass cobalt = 58.9332 amu
therefore:
1 mol Co ------------ 58.9332 g
moles ------------ 50 g
moles = 50 x 1 / 58.9332
moles = 50 / 58.9332
= 0.8484 moles of Co
Hope this helps!
0.8484 moles are in 50 grams of cobalt.
What are moles?A mole is defined as 6.02214076 × [tex]10^{23}[/tex] of some chemical unit, be it atoms, molecules, ions, or others. The mole is a convenient unit to use because of the great number of atoms, molecules, or others in any substance.
Atomic mass cobalt = 58.9332 amu
Therefore:
1 mol Co ------------ 58.9332 g
moles ------------ 50 g
moles = 50 x 1 ÷ 58.9332
moles = 50 ÷ 58.9332
= 0.8484 moles of Co
Learn more about moles here:
brainly.com/question/8455949
#SPJ5
What product(s) are formed during the complete combustion reaction that occurs when methane (CH4) and molecular oxygen (O2) react? CO2 and H4 C and H2O CO2 and H2O C(OH)4
Answer: CO2 and H2O
Explanation: I already took the test it's right
QUICK!!!
The specific heat of mercury is 0.138 J/g Celsius. If 452 g of mercury at 85.0 Celsius are placed in 145 g of water at 23.0 Celsius, what will be the final temperature for both the mercury and the water?
Answer: Thus the final temperature for both the mercury and the water is [tex]28.8^0C[/tex]
Explanation:
The quantity of heat required to raise the temperature of a substance by one degree Celsius is called the specific heat capacity.
[tex]heat_{released}=heat_{absorbed}[/tex]
[tex]Q=m\times c\times \Delta T=m\times c\times (T_{final}-T_{initial})[/tex]
[tex]-[m_1\times c_1\times (T_{final}-T_1)]=[m_2\times c_2\times (T_{final}-T_2)][/tex]
Q = heat absorbed or released
[tex]m_1[/tex] = mass of mercury= 452 g
[tex]m_2[/tex]= mass of water = 145 g
[tex]T_{final}[/tex] = final temperature = ?
[tex]T_1[/tex] = temperature of mercury = [tex]85.0^0C[/tex]
[tex]T_2[/tex] = temperature of water = [tex]23.0^0C[/tex]
[tex]c_1[/tex] = specific heat of mercury = [tex]0.138J/g^0C[/tex]
[tex]c_2[/tex] = specific heat of water= [tex]4.184J/g^0C[/tex]
Now put all the given values in equation (1), we get
[tex]-[452\times 0.138\times (T_f-85.0)^0C]=145\times 4.184\times (T_f-23.0)^0C[/tex]
[tex]T_f=28.8^0C[/tex]
Thus the final temperature for both the mercury and the water is [tex]28.8^0C[/tex]
1. Potassium (K) has an atomic mass of 39.0983 amu and only two naturally-occurring isotopes. The K-41 isotope (40.9618 amu) has a natural abundance of 6.7302%. What is the mass (in amu) of the other isotope
Answer:
38.96383282 amu
Explanation:
39.0983 = (40.9618 [tex]\times[/tex] 0.067302) + ( ? [tex]\times[/tex] (1-0.067302)
39.0983 = 2.756811064 + ( ? [tex]\times[/tex] 0.932698)
subtract 2.756811064 from both sides
36.34148894 = ( ? [tex]\times[/tex] 0.932698)
divide both sides by 0.932698
? = 38.96383282 amu
Answer:
38.96383282 amu
Explanation:
39.0983 = (40.9618 0.067302) + ( ? (1-0.067302)
39.0983 = 2.756811064 + ( ? 0.932698)
subtract 2.756811064 from both sides
36.34148894 = ( ? 0.932698)
divide both sides by 0.932698
? = 38.96383282 amu
Which equation represents the reaction of a weak acid with water
Answer:
Which equation represents the reaction of a weak acid with water? the equation is : HCl + H2O H3O+ + Cl- HCO3– + H2O H2CO3 + OH– H2O H + + OH- HCOOH + H2O H3O+ + HCOO
Explanation:
hope it helps : )
Answer:
Hey mate, here is your answer. Hope it helps you.
HCOOH + H2O ↔ H3O+ + HCOO-
Explanation:-
A strong acid is one which completely dissociates into its corresponding ions in aqueous medium.
In contrast, a weak will only partially dissociate such that there is an equilibrium between the dissociated ions and the undissociated acid.
In the given examples:
HCl, HCO3- and H2CO3 are all strong acids. However, HCOOH i.e. formic acid is a weak acid which dissociates in water to form H3O+ and formate ion, HCOO-
HCOOH + H2O ↔ H3O+ + HCOO-
A 0.04380 g sample of gas occupies 10.0 mL at 290.5 K and 1.10 atm. Upon further analysis, the compound is found to be 25.305% C and 74.695% Cl. What is the molecular formula of the compound?
Answer:
THE MOLECULAR FORMULA FOR THE COMPOUND IS C2 Cl2
Explanation:
mass = 0.04380 g
Volume = 10 mL = 10 / 1000 L = 0.010 L
Pressure = 1.10 atm
R = 0.082 L atm mol^-1 K^-1
Temperature = 290.5 K
Carbon = 25.305 %
Chlorine = 74.695 %
Atomic mass of carbon = 12
Atomic mass of chlorine = 35.5
First calculate the empirical formula by following these steps:
1. Write the percentage composition of the elements involved and divide by its atomic mass
Carbon = 25.305 / 12 = 2.10875
Chlorine = 74.695 /35.5 = 2.1040
2. Divide each by the smaller value
Carbon = 2.10875 / 2.1040 = 1.002
Chlorine = 2.1040 / 2.1040 = 1
3. Round up to the whole number
The empirical formula is C Cl
Next is to calculate the molar mass of the compound using ideal gas equation
PV = mRT/ MM
Mm = mRT / PV
Mm = 0.04380 * 0.082 * 290.5 / 1.10 * 0.010
Mm = 1.0433 / 0.011
Mm = 94.845 g/mol
Mm = 94.85 g/mol
Now that we know the molar mass, we can go on to calculate the molecular formula:
(C Cl) n = Molar mass
( 12 + 35.5) n = 94.85
(47.5)n = 94.85
n = 94.85 / 47.5
n = 1.9968
n ~ 2
The molecular formula can then be written as C2Cl2.
What functional groups are in ch2=chch2oh?
Explanation:
H
|
H-C=C-C-OH
| | |
H H H
in this organic compound the functional groups are OH and alkene
prop-2-enol
since it has a double bond, alkene is the functional group. and also it has OH group so hydroxyl group also the other functional group
• When a mechanism has been investigated in detail, it can be understood on many levels of differing detail. • An additional detail about addition of hydrogen halides to alkenes in non-polar solvents is that additional molecules of hydrogen halide assist the rate-determining proton transfer by hydrogen-bond solvation of the halide ion. • What kinetic order is HI (the value of "x" in the equation below) would HI addition to propene exhibit according to the mechanism above? The predicted kinetic order in HI is . (an integer)
Complete Question
The complete question is shown on the first uploaded image
Answer:
The kinetic order in HI is x= 2
Explanation:
Generally the slow step in a reaction mechanism is the rate determining step
Now with this knowledge at the back of our minds we can see that the number of moles of HI i s 2 which implies that the order of HI is 2m
So we can represent the rate law as
[tex]Rate = k [CH_3 CHCH_2][HI]^2[/tex]
hence
x = 2
Consider the following reaction. 2C2H2(g)+5O2(g)⟶4CO2(g)+2H2O(g) 2C2H2(g)+5O2(g)⟶4CO2(g)+2H2O(g) Compound ΔH∘f (kJ/mol)ΔHf∘ (kJ/mol) C2H2(g)C2H2(g) 227.4227.4 O2(g)O2(g) 00 CO2(g)CO2(g) −393.5−393.5 H2O(g)H2O(g) −241.8−241.8 What is the ΔH∘ΔH∘ of the reaction?
Answer:
ΔH° = -1255.8 kJ
Explanation:
Step 1: Data given
ΔHf∘ C2H2 = 227.4 kJ/mol
ΔHf∘ O2 = 0 kJ/mol
ΔHf∘ CO2 = -393.5 kJ/mol
ΔHf∘ H2O = -241.8 kJ/mol
Step 2: The balanced equation
2C2H2(g)+5O2(g) ⟶ 4CO2(g)+2H2O(g)
C2H2(g)+5/2O2(g) ⟶ 2CO2(g)+H2O(g)
Step 3: Calculate ΔH° of the reaction
ΔH° = (2*ΔHf∘ CO2 + ΔHf∘ H2O) - (ΔHf∘ C2H2)
ΔH° = (2* -393.5 kJ/mol + (-241.8) kJ/mol) - 227.4 kJ/mol
ΔH° = -787 - 241.8 - 227. kJ/mol
ΔH° = -1255.8 kJ
Helium is a very important element for both industrial and research applications. In its gas form it can be used for welding, and since it has a very low melting point (only 0.95 K under 2.5 MPa) it can be used in liquid form to cool superconducting magnets, such as those found in particle physics experiments. Say we have a cylinder of n = 125 moles of Helium gas at room temperature (T = 20° C). The cylinder has a radius of r = 17 cm and a height h = 1.64 m.What pressure is Helium gas under?
Answer:
P = 20.1697 atm
Explanation:
In this case we need to use the ideal gas equation which is:
PV = nRT (1)
Where:
P: Pressure (atm)
V: Volume (L)
n: moles
R: universal gas constant (=0.082 L atm / K mol)
T: Temperature
From here, we can solve for pressure:
P = nRT/V (2)
According to the given data, we have the temperature (T = 20 °C, transformed in Kelvin is 293 K), the moles (n = 125 moles), and we just need the volume. But the volume can be calculated using the data of the cylinder dimensions.
The volume for any cylinder would be:
V = πr²h (3)
Replacing the data here, we can solve for the volume:
V = π * (17)² * 164
V = 148,898.93 cm³
This volume converted in Liters would be:
V = 148,898.93 mL * 1 L / 1000 mL
V = 148.899 L
Now we can solve for pressure:
P = 125 * 0.082 * 293 / 148.899
P = 20.1697 atmHow many grams of CO2 are used when 6.0 g of O2 are produced? Express your answer with the appropriate units.
Answer:
that is why co2 is in the power of 2ik
what is the relative atomic mass of a hypothetical element that consists of the following isotopes in the indicated natural abundances?? pls help
Answer:
87.3
Explanation:
To calculate the relative atomic mass
((84.9*15)+(86.9*12.9)+(87.9*72.1))/15+12.9+72.1
(1273.5 + 1121.01 + 6337.59) / 100
8732.1/100
87.321 = 87.3
2H2+O2->2H20 How many moles of water can be produced if 8 moles H2 are used
1. Which of the following choices demonstrates the law of constant composition? (Slides 2 ‒ 3: Laws on Matter) (a) Nitrogen and oxygen are both found in nature as diatomic molecules. (b) When 20.0 g of nitrogen and 32.0 g of oxygen are combined and allowed to react in two separate experiments, both times the product isolated from reaction contains 14.0 g of nitrogen and 32.0 g of oxygen. (c) Nitrogen and oxygen gases are mixed to produce a sample consisting of 20.0 g of nitrogen and 32.0 g of oxygen. (d) When 14.0 g of nitrogen and 32.0 g of oxygen are mixed and react, there is no measurable change in mass during the reaction. (e) Nitrogen and oxygen are gases found in air, nitrogen is approximately 79% of air and oxygen is approximately 21%.
Answer:
(b) When 20.0 g of nitrogen and 32.0 g of oxygen are combined and allowed to react in two separate experiments, both times the product isolated from reaction contains 14.0 g of nitrogen and 32.0 g of oxygen.
Explanation:
The law of definite proportion states that a gen chemical compound always contains its constituent elements in a fixed ratio by mass, independent on the method of preparation.
The molar mass of Nitrogen and Oxygen would always remain the same, allowing for exact reactant masses (or mole ratio) irrespective of the given amount of sample.
Glyceraldehyde is an aldose monosaccharide. The Fischer projection of D-glyceraldehyde is given below. Draw D-glyceraldehyde using wedge and dash bonds around the chirality center and including ALL hydrogen atoms.
Image is not given in the question, so the image for the question is given below.
Answer:
Fischer projection is a two-dimensional representation of a three-dimensional organic molecule by projection.
Wedge and dash bonds are used to represent the three-dimensional structure of a molecule, in which wedges indicates bonds towards the viewer, solid lines indicates bonds in the plane of the image and dashed lines indicates bonds away from the viewer.
Wedge and dash bonds structure of D-glyceraldehyde is attached below.
Under which set of conditions is ΔGrxn for the reaction A(g)→B(g) most likely to be negative? PA=10.0atm ; PB=0.050atm PA=10.0atm; PB=10.0atm PA=0.050atm; PB=0.050atm PA=0.050atm; PB=10.0atm
Answer:
ΔGrxn for the reaction A(g)→B(g) will most likely to be negative under the PA=10.0atm ; PB=0.050atm condition
The FIRST option is correct
Explanation:
From Thermodynamics,
Using the Gibbs Free Energy (G) formula to determine the reaction A(g)→B(g) most likely to be negative.
Gibbs Free Energy (G) which is the energy associated with a chemical reaction that can be used to do work.
CHECK THE ATTACHMENT FOR THE DETAITALED EXPLANATION
the number of electrons present in 4.2 gram of methane is
Answer:
Explanation:
One CH4 molecules = 10 electrons ( Carbon 6e + 4Hydrogen 4e)
A mole of any substance witll have = 6.023*10^23 atom/ molecuels,
One mole of any substnce is equal is nothing but its moalr mass
Molar mass of CH4 = 16.04
It mean,
16.04 g of CH4 has = 6.023*10^23 molecules of methane
but
4.2 gram of CH4 = 6.023*10^23 * 4.2 /16.04 = 1.58*10^23 molecuels of CH4
So one molecule has =10 electrons
1.58*10^23 molecuels will have = 1.58*10^23 * 10 = 1.58*10^24
Hope this help you
4. If the DNA nitrogen bases were TACCGGAT, how would the other half of
the attached DNA strand read?
Answer:
ATGGCCTA
Explanation:
For this we have to keep in mind that we have a specific relationship between the nitrogen bases:
-) When we have a T (thymine) we will have a bond with A (adenine) and viceversa.
-) When we have C (Cytosine) we will have a bond with G (Guanine) and viceversa.
Therefore if we have: TACCGGAT. We have to put the corresponding nitrogen base, so:
TACCGGAT
ATGGCCTA
I hope it helps!
In a photoelectric experiment a student uses a light source whose frequency is greater than that needed to eject electrons from a certain metal. However, after continuously shining the light on the same area of the metal for a long period of time the student notices that the maximum kinetic energy of ejected electrons begins to decrease, even though the frequency of the light is held constant. How would you account for this behaviour?
Answer:
The metal surface becomes more positive as electrons are lost from it.
Explanation:
Let us note that photoelectric effect refers to a phenomenon in which electrons are ejected from a clean metal surface irradiated with light of appropriate frequency. This photon must possess a frequency above the threshold frequency of the metal and its energy must exceed the work function of the metal. When these conditions are met, electrons are emitted from a clean metal surface, having a constant kinetic energy as long as the frequency of the incident photon remains constant.
However, as photoelectric effect progresses and electrons are lost from the metal surface, the metal surface becomes more positive. The more positive the surface, the greater the attraction of the positive surface for the emitted electrons. This reduces the kinetic energy of the emitted photons even though the frequency of incident photons is held constant.