Answer:
1) 0.1077 moles
2) 137043.2 moles
3) 180.186 grams
4) 6.53×10²² molecules or formula units
5) 1.505×10²³ ions
6) 90.626 grams
7) 0.555 moles
Explanation:
1) The number of moles, n = Mass of the substance/(Molar mass of the substance)
The molar weight of PO₄⁻³ is 94.971 g/mol
The number of moles in 10.23 g of PO₄⁻³ is n =10.23/94.971 = 0.1077 moles
The number of moles in 10.23 g of PO₄⁻³ = 0.1077 moles
2) The number of molecules of Na₂CO₃ in one mole of Na₂CO₃ is given by the Avogadro's number, [tex]N_A[/tex] = 6.02 × 10²³ molecules
Therefore, the number of moles in 8.25 × 10²⁸ molecules of Na₂CO₃ is found by determining how many Avogadro's number of molecules are in 8.25 × 10²⁸ molecules of Na₂CO₃ as follows;
The number of moles in 8.25 × 10²⁸ molecules of Na₂CO₃ = (8.25 × 10²⁸)/(6.02 × 10²³) = 137043.2 moles
The number of moles in 8.25 × 10²⁸ molecules of Na₂CO₃ = 137043.2 moles
3) The molar mass of CH₂O = 30.031 g/mol
Therefore, the mass of 6 of CH₂O = 6 moles × 30.031 g/mol = 180.186 grams
The mass of 6 of CH₂O = 180.186 grams
4) The molar mass of NaCl = 58.44 g/mol
The number of moles of NaCl in 6.34 g of NaCl 6.34/58.44 = 0.1085 moles
1 formula unit of NaCl = 1 molecule of NaCl
The number of molecules in one mole of a substance = [tex]N_A[/tex] = 6.02 × 10²³
Therefore, the number of molecules in 0.1085 moles of NaCl = 6.02 × 10^(23) × 0.1085 = 6.53×10²² molecules or formula units
5) The number of ions per mole of any substance is give by Avogadro's number, [tex]N_A[/tex] = 6.02 × 10²³ ions,
The number of ions in 0.25 moles of Cu⁺² = 0.25×6.02 × 10²³ ions = 1.505×10²³ ions
The number of ions in 0.25 moles of Cu⁺² = 1.505×10²³ ions
6) The molar mass of CH₄ = 16.04 g/mol
The number of moles, n, in 3.4×10²⁴ = 3.4×10^(24)/(6.02×10^(23)) = 5.65 moles 5.65*16.04
The mass of 5.65 moles of CH₄ = 5.65 moles × 16.04 g/mol = 90.626 grams
The mass of 3.4×10²⁴ molecules of CH₄ = 90.626 grams
7) The density of water = 1 g/mL
The volume of the water 10 mL
The mass of the water = Volume × Density = 10 mL × 1 g/mL= 10 grams
The molar mass of water = 18.015 g/mol
The number of moles of water in 10 g of water = mass/(Molar mass) = 10/18.015 = 0.555 moles.
show bond formation in magnesium chloride
mg has a 2 in its valence shell
it will become mgcl2
. . . .
: Cl -------- Mg ------ Cl :
. . . .
12. Classify the following as conduction, convection or radiation. a. A steel mug kept near a stove becomes hot after some time. b. The metal handlebars of a bicycle are colder than plastic hand grips. c. Some people get sunburn when they go out in the sun for a long time. d. The paper kept above a candle flame starts burning after some time.
A - convection
B - conduction
C - radiation
D - convection
Na-23 has 12 neutrons. What is it’s atomic number?
Answer:
11
Explanation:
Data obtained from the question include:
Mass number = 23
Neutron = 12
Atomic number =.?
Next, we shall determine the number of protons present in the element.
This can be achieved by doing the following:
Mass number = Proton + Neutron
Mass number = 23
Neutron = 12
Proton =...?
Mass number = Proton + Neutron
23 = Proton + 12
Collect like terms
Proton = 23 – 12
Proton = 11
The atomic number of an element is equal to the proton number.
Atomic number = proton number
Proton number = 11
Atomic number = proton = 11
Therefore, the atomic number is 11.
what happens when ca no3 2 is heating it gives CaO ,NO2 and 02
Answer:
balanced equation:
2Ca(NO3)2 (aq)-----> 2CaO (s) + 4NO2 (g) + O2 (g)
So heating 2 moles of Ca(NO3)2 gives 2 moles of CaO, 4 moles of NO2 and 1 mole of O2. This is a heat decomposition reaction. It gives a white precipitate (CaO), and brown pungent gas (NO2).
Answer:
The balanced equation of the reaction is below.
Explanation:
2Ca(NO3)2 -----> 2CaO + 4NO2 + O2.
Label the following as either an Element, Compound, or Mixture.
Answer:
27. Element (Because it contains all same atoms)
28. Compound (It contains atoms held together through chemical bonds)
29. Element (it contains all same atoms)
33. Mixture (It contains different atoms but they are not held together through chemical means)
34. Compound (Different atoms held together through chemical means)
35. Mixture (Mixture of elements and compounds)
30. Element (it contains all same atoms)
31. Mixture (Mixture of elements and compounds)
32. Element (Contain all same atoms although held together through chemical means they are not compounds)
calculate the mass of sodium sulphate required to prepare its 20%of solution in 100 g ofwater
Answer:
25 g
Explanation:
Mass percent implies the mass of solute dissolved in a solution
Mass percent = mass of solute/mass of solute + mass of solvent × 100/1
Since mass percent concentration= 20%
Mass of solvent = 100g
Let mass of solute = x
Hence;
20 = x/x +100 ×100/1
20/100= x/x + 100
0.2 = x/x + 100
0.2(x + 100) = x
0.2x + 20 = x
20 = x - 0.2x
20 = 0.8x
x= 20/0.8
x= 25 g
how to make a salt by neutralization reaction
Answer:
Acid+Base=Salt+water
This is the formula of neutralization reaction.
According to this formula you can make salts by reacting an acid with a base.
Hope this helps ❤❤❤.
Period, group and atomic number of the elements that have the following electrical configurations: 1s2 2s2 2p3 1s2 2s2 2p6 3s2 1s2 2s2 2p5
Answer:
If you follow the periodic table and its orbitals, you'll see that the element that has the electron configuration of 1s²2s²2p³ is Nitrogen. It's period, group, and atomic number are 2, 15, and 7 respectively. The other 2 are Neon, who's period, group, and atomic number are 2, 18, and 10 and the last one is Fluorine, who's period, group, and atomic number are 2, 17, and 9.
D Serum Levels Of 4 Mcg/mL, Calculate The Dose, In Milligrams, For A 120-lb Patient That May Be Expected To Result In A Blood Serum Gentamicin Level Of 4.5 Mcg/mL. This problem has been solved! See the answer If the administration of gentamicin at a dose of 1.75 mg/kg is determined to result in peak blood serum levels of 4 mcg/mL, calculate the dose, in milligrams, for a 120-lb patient that may be expected to result in a blood serum gentamicin level of 4.5 mcg/mL.
Answer:
The patient requires a dose of 107.2 mg of gentamicin
Explanation:
A dosage of 1.75 mg per Kilogram body weight results in blood serum levels of 4.5 mcg/mL
This means that; 1.75 mg/ kg = 4.0 mcg/mL
Therefore, dosage of gentamicin in mg/kg that will result in 4.5 mcg/mL blood serum level = (1.75 mg/Kg * 4.5 mcg/mL) / 4.0 mcg/mL
Dosageof gentamicin = 1.97 mg/Kg
1-lb = 0.453592 Kg
Weight of 120-lb patient in Kg = 120 * 0.453592 = 54.43 Kg
Dose in mg required by patient = 1.97 mg/Kg * 54.43 Kg = 107.2 mg
Therefore, the 120-lb patient requires a dose of 107.2 mg of gentamicin to result in a blood serum level of 4.5 mcg/mL
The steady state vital to life is possible because:________
a. the cell cannot convert energy from one form to another.
b. all cells are autotrophic.
c. all reactions are exothermic.
d. the cell continually takes up energy from the environment.
e. all reactions are at equilibrium.
Answer: The correct answer is e) all reactions are at equilibrium.
Explanation: In order for cellular vitality to develop, it is necessary for it to be in energetic balance with the environment, that is, to give and receive energy with the environment that surrounds it through endothermic or exothermic reactions. That is why the development of life is considered a system that constantly exchanges with the environment. In turn, that the cell unit maintains a balance with the environment causes homeostasis to occur among the whole organism.
To make a table of elements, dmitri
The question is incomplete, the complete question is;
To make a table of the elements, dimitri Mendeleev sorted the elements according to their?
Answer:
Atomic weights
Explanation:
Dimitri Medeleeve is a Russian scientist who worked assiduously on the project of developing a system of classifying all the elements. His periodic table was filled with spaces as many atoms weren't yet discovered. 'Eka' prefix was used to name some elements whose properties closely resembled that of their predecessors in Mendeleev's system of classification.
The dependence of the atomic properties on the weight of the atom was the basis for Mendeleeves' original classification. According to Medeleeve, elements having similar chemical properties are also expected to have similar atomic weights and their atomic weights was found to increase regularly.
The Mendeleeve concept of periodic arrangement of elements is the closest precursor of the modern periodic table as it is used in chemistry. Mendeleev arranged the elements in order of increasing relative atomic mass .
What letter represents the enthalpy of reaction?
Answer:
Option D. T
Explanation:
Enthalpy change (ΔH) is simply the difference between the heat content of the product (Hp) and the heat content of the reactant (Hr). Mathematically, it is expressed as:
Enthalpy change (ΔH) = Heat of product (Hp) – heat of reactant (Hr)
ΔH = Hp – Hr
From the diagram given above, the difference between the heat content of product and the heat content of reactant is T.
Therefore, the enthalpy change of the reaction is T.
To what temperature should 2.3L of a gas at 25degree Celsius be heated in order to expand its volume to 4 L under constant pressure
Answer:
518.52K
Explanation:
Charles law, which describes the direct relationship between the volume and the temperature of a gas when the pressure is constant, will be used for this question. The Charles law equation is:
V1/T1 = V2/T2
Where; V1 is the volume of the gas at an initial state (Litres)
T1 is the absolute temperature of the gas at an initial state (Kelvin)
V2 is the volume of the gas at a final state (Litres)
T2 is the absolute temperature of the gas at a final state (Kelvin)
According to the question, V1 = 2.3L, T1 = 25°C, V2 = 4L, T2 = ?
We need to convert the temperature to the absolute temperature unit in Kelvin (K) i.e.
T(K) = T(°C) + 273.15
T(K) = 25°C + 273.15
T1 (K) = 298.15K
To find for T2 in the equation, we make T2 the subject of the formula:
T2 = V2 × T1 / V1
T2 = 4 × 298.15 / 2.3
T2 = 1192.6/2.3
T2 = 518.52
Thus, the temperature must be heated to 518.52K in order to expand to a volume of 4L. This answer is in accordance to Charles law that the volume increases with increase in temperature and vice versa.
Which of the following elements does not lose an electron easily? NA F MG AL
Answer:
F
EXPLANATION
Among the given elements fluorine(F)can not lose electrons easily because of its high electron affinity, high nuclear charge and high electronegativity.
Answer:
F
Explanation:
it won't lose electron , rather it would gain electron to complete its octate......
Electronic Configuration of F = 2,7
So F will gain 1 electron ....
Ammonia is produced when a mixture of of ammonium chloride and substance C is heated. What is substance X?
suppose a 22.092 g sample of 1 1 mixture of acetylferrocene and ferrocene was sepeerated by column chromatography and the recovered fractions weighed 9.017 g acetylferrocene and 8.075 g ferrocene what was the eprcent recovery of acetyl ferrocene
Answer:
Percentage recovery of acetylferrocene = 81.6%
Explanation:
Mass of the sample mixture = 22.092 g
Ratio of mixture of acetylferrocene and ferrocene = 1 : 1
This means that the sample conatains equal amounts of acetylferrocene and ferrocene.
Therefore the mass of each sample in the mixture = 22.092 g / 2 = 11.046 g
Mass of acetylferrocene recovered = 9.017 g
Percentage recovery of acetylferrocene = (mass of recovered/ mass in sample) * 100%
Percentage recovery of acetylferrocene = (9.017 g / 11.046 g) *100%
Percentage recovery of acetylferrocene = 81.6%
PLEASE HELP ME
One method to produce nitrogen in the lab is to react ammonia with copper (II) oxide: NH3(g) + CuO(s) ---> Cu(s) + H2O(l) + N2(g). After using 40.0 grams of NH3, 15.5 grams of N2 are produced. What is the percent yield of nitrogen in the reaction?
Answer:47.05% is the percent yield of nitrogen in the reaction.
Explanation:
heoretical yield of nitrogen gas = x
Moles of ammonia =
According to reaction,2 moles of ammonia gives 1 mol of nitrogen gas.
Then 2.3529 mol of ammonia will give:
of nitrogen gas
Mass of 1.1764 moles of nitrogen gas,x = 1.1764 mol × 28 g/mol=32.94 g
Experiential yield of nitrogen gas = 15.5 g
Percentage yield:
hope that help
47.05% is the percent yield of nitrogen in the reaction.
Which statement describes an electron?
Answer:
The statement that describes an electron is "It has a negative charge and is located in orbitals around the nucleus." Electrons are the smallest of the three particles that make up atoms
Explanation:
Electrons are found in shells or orbitals that surround the nucleus of an atom
Electrons are the sub-atomic particles that carry a negative charge over them. In the atom, the electrons are found in the orbitals or the shells around the nucleus. Thus, option D is correct.
What are electrons?
Electrons are the smallest sub-atomic particle that has been known to carry a negative charge and are found in the orbitals of the atom. The charge carried by an electron is 1.602 x 10⁻¹⁹ coulomb and is small than the proton and neutron.
They revolve around the nucleus in their orbits and exhibit the properties of waves and matter. The number of electrons and protons are the same in a neutral atom which makes the atomic number.
Therefore, the electrons have been known to carry a negative charge that revolves in orbit around the nucleus.
Learn more about electrons here:
https://brainly.com/question/11670765
#SPJ6
Your question is incomplete, but most probably your full question was, Which statement describes an electron?
It has a positive charge and is located in the nucleus. It has a positive charge and is located in orbitals around the nucleus. It has a negative charge and is located in the nucleus. It has a negative charge and is located in orbitals around the nucleusanswer the question briefly: How can atom collapse and why are atoms stable?
The nuclei of atoms become unstable when the repelling forces of the protons cannot be balanced by the number of neutrons in the nucleus. It then re-arranges itself randomly to a more stable configuration by emitting any of a series of particles. During radioactive decay, an atom does not collapse.
Since an atom is mostly empty space - that is it’s nucleus is relatively distant from the electron shells so, in the presence of extreme forces such as gravity inthe collapse of a large star, the inward pressures on the atom overcome the natural balance of the atomic structure and the ‘empty space’ disappears as nuclei are mashed together by the intense pressures and a neutron star is formed. Under even more external pressure, even the neutron star can collapse to form a black hole.
An atom of an element is shown by the model. A gray circle is surrounded by 4 concentric circles. The innermost circle has gray dots at the north and south positions; the second ring has 8 equally spaced dots, aligning with the inner ring at north and south; the third ring has 14 dots, equally spaced, aligned with the other rings at north and south; the outer ring has dots at north and south. How is this model useful? It shows how electrons are distributed in the shells of an iron atom. It shows how electrons are distributed in the shells of a cobalt atom. It shows how orbitals are distributed in the shells of an iron atom. It shows how orbitals are distributed in the shells of a cobalt atom.
The correct answer is A. It shows how electrons are distributed in the shells of an iron atom.
Explanation:
In the model described, the circles represent the orbitals or shells of the atom, while the dots represent the distribution of electrons (negatively charged sub-particles). Additionally, the description shows the general electronic configuration of this atom is 2, 8, 14, 2, which means in the first orbital there are two electrons, in the second there are eight electrons, in the third, there are fourteenth electrons and in the fifth orbital there are two electrons. This electronic configuration occurs in the atoms of iron. Also, this differs from Cobalt because in cobalt the third orbital has 15 electrons. Thus, the model "shows how electrons are distributed in the shells of an iron atom".
Answer:
a. it shows how electrons are distributed in the shells of an iron atom
Explanation:
edge 2021
(:
If he wants to model a longitudinal wave that carries more energy, how should he move the end of the spring?
Answer:
they won
Explanation:
Question 7 of 25
What is an energy level?
A. The total energy possessed by all the electrons of an atom
B. The energy contained within the nucleus of an atom
C. The energy required to remove an electron from its nucleus
D. The energy possessed by an electron at a set distance from the
nucleus
SUBMIT
Answer:
d)the energy possessed by an electron at a set distance from the nucleus
write chemical equation for the following decomposition reactions. Aluminum oxide(s) decomposes when electricity is passed through it.
Answer:
2Al2O3 (l) ---> 4Al (l) + 3O2 (g)
Explanation:
The reaction is the electrolysis of aluminium oxide. It decomposes aluminium oxide (Al2O3) into aluminium metal (Al) and Oxygen (O2). In this process, aluminium oxide is molten (liquid state) so that ions can move to complete the electricity circuit.
Al2O3 (l) ---> Al (l) + O2 (g)
Balance the equation:
2Al2O3 (l) ---> 4Al (l) + 3O2 (g)
Which of the following observations indicates that atoms of all elements contain small, negatively charged particles? Alpha particles are repelled by cathode rays of elements. Cathode rays are deflected towards a positively charged rod. A particular frequency of light is produced by a gas in an excited state. Certain areas of the atom called orbitals contain all the charged particles.
Answer:
The correct option is;
Cathode rays are deflected towards a positively charged rod
Explanation:
Cathode rays are beam of electrons emitted from the cathode in a vacuum tube and moving towards the anode, due to the difference in the voltage between the electrodes
The discovery of the electrons was through the proof by Thomson that cathode rays were a negatively charged, previously unknown particle, which was to become known as the electron.
Answer:
Cathode rays are deflected towards a positively charged rod
Explanation:
i took the exam this is correct
In an endothermic reaction, a drop in temperature would be observed. TRUE FALSE
Explanation:
If the reaction is endothermic as written, an increase in temperature will cause the forward reaction to occur
Name a Solid, Liquid, and a Gas. Solid: Liquid: Gas:
Answer:
Gas - Steam
Solid - Rock
Liquid - Juice
Answer:
Solid: Ice
Liquid: Water
Gas: Steam or Water vapor
Explanation:
This is a common example to answer your question. Some other examples are:
-most metals(ex: iron, tin, copper, gold) These are solids
-milk, juice, hot chocalate, any soda drink These are liquids
-hydrogen, helium, carbon dioxide, oxygen These are gases
Hope this helps!
what particle determines the name of the element?
Answer:
The protons determine the name of an element and also atomic number because its the same as protons.
Energy from a reaction was determined to be 3870 J using a water calorimeter, when burning 9.00 grams of H2. What is the total enthalpy of the reaction?
Answer:
860 J / mol
Explanation:
Enthalpy = Energy / no. of moles
no. of moles = mass / molar mass
Take the atomic mass of H = 1.0,
molar mass of H2 = 1.0 x 2
= 2.0
no. of moles of H2 = 9.00/2
= 4.5 mol
Hence,
Enthalpy = 3870 / 4.5
=860 J / mol
What statement describes the cause for sibling rivalry between both brothers? The older son shared his fears about providing financial support for the family after graduating. The sons challenged each other by competing for the highest grade point average that year. The younger son expressed feelings about his parents showing favoritism to his older sibling. The sons disagreed over the handling of family tasks once the younger son heads off to college
Answer:
c
Explanation:
you took the test on edge
The statement describes the cause for sibling rivalry between both brothers is The younger son expressed feelings about his parents showing favoritism to his older sibling. Hence , Option (C) is correct.
What is Sibling rivalry ?Sibling rivalry is the jealousy, competition and fighting between brothers and sisters.
It is a concern for almost all parents of two or more kids.
Problems often start right after the birth of the second child.
Sibling rivalry usually continues throughout childhood and can be very frustrating and stressful to parents.
Therefore, The statement describes the cause for sibling rivalry between both brothers is The younger son expressed feelings about his parents showing favoritism to his older sibling. Hence , Option (C) is correct.
Learn more about Sibling rivalry here ;
https://brainly.com/question/11790181
#SPJ2
How many significant figures are there in 6.07x10^-15?
Answer:
3
Explanation:
6.07 has 3 digits and all are significant