Answer:
a. 82.68 g b. 9.8 min
Explanation:
a. The amount of gold deposited by 5 A current in 2 hrs 15 mins
Since charge Q = It where I = current = 5 A and time = 2 hrs 15 mins = 2 × 60 min + 15 min = 120 + 15 min = 135 min = 135 × 60 s = 8100 s
Q = 5 A × 8100 s
= 40500 C
Also, Q = nF where n = number of moles of gold deposited and F = Faraday's constant = 96500 C
n = Q/F = 40500 C/96500 C = 0.4195 moles ≅ 0.42 mole
Now n = m/M where m = mass of gold and M = molar mass of gold = 197
m = nM
= 0.42 × 197 g
= 82.68 g
b. The time taken for 6g of gold to be deposited.
We first find the number of moles of gold in 6g of gold
Since n = m/M and m = 6 g
n = 6/197 = 0.0305 mole
Q = It = nF
t = nF/I
= 0.0305 mol × 96500 C/5 A
= 2939.09 mol C
= 587.82 s
Changing t to minutes
587.82/60 s = 9.8 min
1. The atomic number of an element is 23 and its mass number is 56.
a. How many protons and electrons does an atom of this element have?
b. How many neutrons does this atom have?
Answer:
23 protons, 23 electrons, 33 neutrons
Explanation:
I don't know why my answer got deleted but no worries, I can answer again. The number of protons and electrons is equal to the atomic number which is 23 and the number of neutrons is 56 - 23 = 33 because atomic mass denotes the number of protons and neutrons.
when a substance goes directly from a solid state to a gas state as dry ice
Answer:
Sublimation
Explanation:
Sublimation refers to the process by which the change of matter takes place directly from solid to liquid state. The matter from the solid-state directly changes into the gaseous state without changing into the liquid state. More energy is required in this process. This is an endothermic reaction. Dry ice is the solid carbon dioxide sublimes in the air.
When sound molecules stack up" in front of high-speed flights, what could
happen?
Answer: The added pressure could cause pilots to become disorinated
Explanation:
Answer:
When sound molecules stack up in front of high-speed flights, loud noises are produced that can damage the ears.
Which of the following reactants can oxidize sodium?
lithium
barium
aluminum
potassium
Answer:
The answer is Aluminum
Hope this helps you
Silver is composed of a single type of atom and cannot be broken down into different substances. Silver is an example of a(n)
ОА.
element
ОВ.
compound
molecule
Earth's gravitational potential energy: GPE = mgh = Gravity (9.81m/s2) *
Mass (kg) x Height (m)
Kinetic energy: KE= Imov?
How do the mass and speed of an object affect the kinetic energy?
Answer:
as mass and the square of speed is directly proportional to the the kinetic enegry so, more there will be mass and speed there will be more kinetic enegry.
How much oxygen will contain the same number of atoms as the number of molecules in 73 g of HCI?
Answer:
64g of O2.
Explanation:
We'll begin by calculating the number of molecules in 73g if HCl.
This is illustrated below:
From Avogadro's hypothesis, we understood that 1 mole of any substance contains 6.02×10²³ molecules. This implies that 1 mole of HCl also contains 6.02×10²³ molecules
1 mole of HCl = 1 + 35.5 = 36.5g
Thus, if 36.5g of HCl contains 6.02×10²³ molecules, then 73g of HCl will contain = (73 x 6.02×10²³)/36.5 = 1.204×10²⁴ molecules.
Therefore, 73g of HCl will contains 1.204×10²⁴ molecules.
Now, we shall determine the mass of oxygen that will contain 1.204×10²⁴ molecules.
This can be obtained as follow:
1 mole of O2 = 16x2 = 32g
32g of O2 contains 6.02×10²³ molecules.
Therefore, Xg of O2 will contain 1.204×10²⁴ molecules i.e
Xg of O2 = (32 x 1.204×10²⁴)/6.02×10²³
Xg of O2 = 64g
Therefore, 64g of O2 will contain the same number of molecules (i.e 1.204×10²⁴ molecules) in 73g of HCl.
25cm3 of 0.2mol/dm3 barium hydroxide solution reacted with 22.8cm3 hydrochloric acid. Calculate the concentration of the hydrochloric acid in mol/dm3. Ba(OH)2 + 2HCl BaCl2 + 2H2O
Explanation:
1 mol of Ba(OH)2 = 2 moles of HCl
please help pls help 20 points Which of the following is a myth about water conservation? An important part of water conservation is preventing water pollution. Using an electric clothes dryer conserves more water than air-drying clothes. Buying bottled water does not conserve more water than drinking from the tap. A front-loading washing machine uses less water than a top-loading washing machine.
Answer:
Air-drying clothes conserves more water than using an electric clothes dryer.
What is Rutherford atomic modle
Answer:
Rutherford's atomic model explained how the electrons surrounded the nucleus of protons and neutrons. His model showed how J. J. Thomson's Plum Pudding model was incorrect.
Answer:Rutherford model of an atom shows that an atom is mostly an empty space,with electrons orbiting a fixed positively charged nucleus in set.
Explanation:
give an example of process you notice or use each day that obeys the law of conservation of mass. and explain how this process works
Answer:
Cellular respiration:
[tex]C_6H_{12}O_6+6O_2\rightarrow 6CO_2+6H_2O[/tex]
Explanation:
Hello,
In this case, the law of conservation of mass states that matter cannot be created nor destroyed but modified, therefore, typical examples are the raft chemical reactions in nature or carried out in a laboratory. Thus, a typical one that could be daily found is in the cellular respiration wherein glucose and oxygen are converted into carbon dioxide, water and energy for us to use it in our daily activities. It is chemically represented by:
[tex]C_6H_{12}O_6+6O_2\rightarrow 6CO_2+6H_2O[/tex]
Law of conservation of mass is verified as six carbon atoms are before and after the chemical reaction, twelve hydrogen atoms are before and after it and eighteen oxygen atoms as well.
Best regards.
2N2H4+ N2O4———3N2+4H2O SalmaKhan99 avatar How many grams of N2 gas will be formed by reacting 100g of N2H4 and 200g of N2 Kindly answer please
Answer:
131.26 g
Explanation:
From the balanced equation,
2 moles of N₂H₄reacts with 1 mole of N₂O₄ to give 3 moles of N₂
Now number of moles of N₂H₄ present in 100 g N₂H₄ is n = 100 g/molar mass N₂H₄.
Molar mass N₂H₄ = 2 × 14.01 g/mol + 1 × 4 g/mol = 28.02 g/mol + 4 g/mol = 32.02 g/mol
n₁ = 100/32.02 = 3.123 mol
Also
Now number of moles of N₂O₄ present in 200 g N₂O₄ is n = 200 g/molar mass N₂O₄.
Molar mass N₂O₄ = 2 × 14.01 g/mol + 16 × 4 g/mol = 28.02 g/mol + 64 g/mol = 92.02 g/mol
n₂ = 200/92.02 = 2.173 mol
Since the mole ratio of N₂H₄ to N₂O₄ is 2 : 1, We require 2 × 2.173 mol N₂H₄ to react with 2.173 mole N₂O₄
Number of moles of N₂H₄ required is 4.346. But the number of moles of N₂H₄ present is 3.123 so N₂H₄ is the limiting reagent.
So, from the equation, 2 moles of N₂H₄ produces 3 moles of N₂
Therefore number of mole N₂ = 3/2 moles of N₂H₄ = 3/2 × 3.123 mol = 4.6845 mol
From n = m/M where n = number of moles of nitrogen gas = 4.6845 mol and M = molar mass of nitrogen gas = 28.02 g/mol and m = mass of nitogen gas.
m = nM = 4.6845 mol × 28.02 g/mol = 131.26 g
So the mas of nitrogen gas produced is 131.26 g
What is the number of molecules of 140 g of CO?
Answer:
3.01
[tex] \times [/tex]
10-22
moles=mass/RMM
moles=140/28
=5moles
1mole=6.02*10-23
5moles=?
=3.01*10-22
hope this is helpful
Assuming constant pressure, rank these reactions from most energy released by the system to most energy absorbed by the system, based on the following descriptions:__________.
A: Surroundings get colder and the system decreases in volume.
B: Surroundings get hotter and the system expands in volume.
C: Surroundings get hotter and the system decreases in volume.
D: Surroundings get hotter and the system does not change in volume.
Answer:
C: The surroundings heat up and the system decreases in volume.
D: The surroundings heat up and the system does not change volume.
B: The surroundings heat up and the system expands in volume.
A: The surroundings get cold and the system decreases in volume.
Explanation:
The most exothermic reactions are those that release heat, that is to say, they give up the heat as it cools and the surroundings heat up.
As for endothermics, that is, those that absorb or capture the heat of the medium, they are variables that cool the environment that surrounds them and increase their internal temperature
What is the valence shell electronic configuration of Alkali Metals , Alkaline Earth Metals, Halogens and Noble Gases?
Answer:
alkali metals: 1
alkaline earth metals: 2
Halogens: 7
noble gases : 8
Answer:
Alkali Metals: 1 valence electron
Alkaline Earth metals: 2 valence electrons
Halogens: 7 Valence electron
Noble Gases: 8 Valence electrons
a compound X is formed by an element y which is in the form of pellet. The compound X is also the product of chlor - alkali process. Identify X and Y
Answer:
X is sodium hydroxide (caustic soda, NaOH)
y is sodium (Na)
Explanation:
The process of industrial electrolysis of sodium chloride solution by which chlorine and sodium hydroxide (caustic soda) can be produced is known as the chlor-alkali process as follows;
2NaCl + 2H₂O → Cl₂ + H₂ + 2NaOH
Given that the compound X is formed from a element y which is in the form of a pellet, we have;
The element in the above reaction that can exist as pellet is the silver white metallic sodium pellet
Therefore, the compound X is NaOH and the element y is sodium, Na.
Why was Niels Bohr atomic model superior to all the earlier models
Answer:
because it showed how the electron could orbit the nucleus without falling into it.
Please help, I don't under stand! Balance the following oxidation-reduction reaction and indicate which atoms have undergone oxidation and reduction. ____FeCl3 + ____H2S Imported Asset ____FeCl2 + ____S + ____HCl
Answer:
3 FeCl3 + H2S = 2 FeCl2 + S + 2 HCl
Explanation:
Fe goes form +3 to +2
S goes from -2 to 0
H and Cl are spectator ions
Fe3+ + 1e-= Fe2+
H2S = S + 2 H+ + 2e-
3 Fe3+ + H2S = 2 Fe2+ + S + 2 H+
3 FeCl3 + H2S = 2 FeCl2 + S + 2 HCl
Study the reactions for the formation of compounds from their elements. I. C(s) + O2(g) → CO2(g) ΔHf = −394 kJ II. H2(g) + 12O2(g) → H2O(l) ΔHf = −242 kJ III. 2C(s) + 3H2(g) → C2H6(g) ΔH =−84 kJ The combustion of C2H6 is shown by the following equation: C2H6(g) + 72O2(g) → 2CO2(g) + 3H2O(l) Which option correctly gives the enthalpy of combustion of 0.2 moles of C2H6(g)? −1,430 kJ 286 kJ −286 kJ 1,430 kJ Exam 3 Click on the numbers to jump from one question to another. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
Answer:
The correct option is -286 kJ
Explanation:
The given parameters are
C(s) + O₂(g) → CO₂(g) ΔHf = -394 kJ
H₂(g) + 12O₂(g)→H₂O ΔHf = -242 kJ
2C(s) + 3H₂(g)→C₂H₆(g) ΔH = -84 kJ
Te given equation is C₂H₆(g) + 7/2O₂(g) →2CO₂(g) + 3H₂O(l)
The heat of formation or enthalpy of combustion = Heat of formation of the products - Heat of formation of the reactants
The enthalpy of combustion of the reaction = 2*(-394) + 3*(-242)- ((-84)+7/2*0)) = -1,430 kJ
Given that the reaction consists of one mole of C₂H₆(g), we have;
The enthalpy of combustion of one mole of C₂H₆(g) = -1,430 kJ
Therefore, the enthalpy of combustion of 0.2 mole of C₂H₆(g) = -1,430 kJ × 0.2 = -286 kJ
The correct option = -286 kJ.
Answer:
Positive 1,430
Explanation:
Two students are given different samples of a substance and are instructed to determine the properties of the substance.Which statement describes a property that will be the same for both students
Answer:
The boiling point of the substances
Explanation:
Because Boiling point is an intensive property.
(7) Give two examples of solid poeciption
Use the periodic table to answer the following questions. How many valence electrons does oxygen have?
Answer:Oxygen has 6 valence electrons
A=2
B=2
C=4
The charge of an oxygen Ion is -2
Explanation:
According to the electronic configuration,there are 6 valence electrons in an oxygen atom.
What is electronic configuration?
Electronic configuration is defined as the distribution of electrons which are present in an atom or molecule in atomic or molecular orbitals.It describes how each electron moves independently in an orbital.
Knowledge of electronic configuration is necessary for understanding the structure of periodic table.It helps in understanding the chemical properties of elements.
Elements undergo chemical reactions in order to achieve stability. Main group elements obey the octet rule in their electronic configuration while the transition elements follow the 18 electron rule. Noble elements have valence shell complete in ground state and hence are said to be stable.
Learn more about electronic configuration,here:
https://brainly.com/question/29757010
#SPJ2
What ion is formed when an atom of mercury (Hg) loses two electrons?
Hg–1
Hg–2
Hg+1
Hg+2
Answer: Hg +2
Explanation:
Hg+2 is formed when mercury loses two electrons.
Hg ------> Hg +2 + 2 e-
Answer:
Hg+2 (D) is the correct answer
Explanation:
the person above me is correct, hope this helps, have a good one
Which compounds give one singlet in the 1H NMR spectrum? CH3CH3 1461113dichloro22dibromo 1461123dimethyl2butene CH3―C≡C―CH3 CH2═CHCH═CH2 14611cyclohexadione 14611cyclopentane 14611123tribromopropane 14611ketone 14611ester
Answer:
CH3CH3, 1,3- dichloro-2,2- dibromo, 2-butyne, cyclopentane, 2,3- dimethylbut-2-ene, 2,2,4,4- tetramethlpenta-3-one.
Explanation:
This problem or question has to do with spectroscopy. Spectroscopy is one of the Important aspect of physical Chemistry. It is important because it helps in the identification of chemical samples or compounds. The Nuclear Magnetic field work generally on the principle of absorption of energy.
The following compounds as given in the question above shows singlet in the 1H NMR spectrum.
(1). CH3CH3: shows singlet in the 1H NMR spectrum at 0.86 ppm.
(2). 1,3- dichloro-2,2- dibromo; shows singlet.
(3). 2- butyne shows singlet
(4). Cyclopentane shows singlet.
(5). 2,3 - dimethylbut-2-ene shows singlet.
(6). 2,2,4,4- tetramethlpenta-3-one shows singlet.
Kindly note that I have used the IUPAC naming system to name the Compounds in the question above.
Explain the methods of passive transport that move molecules across the plasma membrane of the cell.
What are the percent compositions of hydrogen and oxygen in water
Answer:
H % = 11.11%
O % = 88.89%
Explanation:
atomic weight of H = 1
atomic weight of O = 16
each molecule of water contains 2 atoms of H and one atom of O
hence molecular weight of water = 18
H % = 2 x 100/18 = 11.11%
O % = 16 x 100/18 = 88.89%
Answer:
-H= 11.19%
-O= 88.81%
Explanation: the answer above mine is incorrect!, i just did it and i got it right, the answer is h= 11.19% and O= 88.81% hope it helps!
What are the masses of subatomic particles in their atomic mass unit
Answer:
Subatomic particles are the proton (1 amu), neutron (1 amu), and electron (0 amu)
Explanation:
Atomic mass unit (amu; dalton): A unit of mass equal to exactly 1/12 the mass of one 12C atom, or 1.660538921 x 10−27 kg. This is the approximate mass of one proton or one neutron. It is the basis of atomic weights.
Answer:
[tex]\boxed{\mathrm{see \: below}}[/tex]
Explanation:
Protons have a mass of 1 amu (atomic mass unit).
Electrons have a mass of [tex]\frac{1}{1840}[/tex] amu (atomic mass unit).
Neutrons have a mass of 1 amu (atomic mass unit).
DNA Mutations
Pre-Test
Active
1
A mutation causes a dog to be born with a tail thatis shorter than normal.
Which best describes this mutation
Answer:
Explanation:
A
Does anybody know how to do q4. Please show working out thanks.
Answer:
% purity of limestone = 96.53%
Explanation:
Question (4).
Weight of impure CaCO₃ = 25.9 g
Molecular weight of CaCO₃ = 40 + 12 + 3(16)
= 100 g per mole
We know at S.T.P. number of moles of CO₂ = 1 and volume = 22.4 liters
From the given reaction, 1 mole of CaCO₃ reacts with 1 mole or 22.4 liters of
CO₂.
∵ 22.4 liters of CO₂ was produced from CaCO3 = 100 g
∴ 1 liter of CO₂ will be produced by CaCO₃ = [tex]\frac{100}{22.4}[/tex]
∴ 5.6 liters of CO₂ will be produced by CaCO₃ = [tex]\frac{100\times 5.6}{22.4}[/tex]
= 25 g
Therefore, % purity of CaCO₃ = [tex]\frac{\text{Weight calculated}}{{\text{Weight given}}}\times 100[/tex]
= [tex]\frac{25}{25.9}\times 100[/tex]
= 96.53 %
help me with this
hurricans are most likely to hit the gulf of Mexico and the Caribbean is this classified as weather or climate please answer
Answer
Climate, because this describes what the weather is like over a long period of time.