Answer:
[tex]E[/tex]Explanation:
Here, we want to identify the elements in BeSO4 in their standard state as the reactants and BeSO4 as the product
From what we have, there are 4 atoms of oxygen, 1 atom of Beryllium, and 1 atom of sulfur
In their standard state, oxygen is a gas, Berrylium and Sulfur are solids
The number of elements atom on the reactant side must be equal to that on the product side
Thus, we have the correct choice of answer as E
A 120 mg sample of technetium-99m is used for a diagnostic test. If technetium-99m has a half-life of 6.0 h, how many milligrams of the technetium-99m sample remains active 23 h after the test?
Answer:
Explanation:
Here, we want to get the number of mg of the atom that would remain
Half-life refers to the time taken for exactly half the mass of a radioactive isotope to be lost to radiation
From the question, the half-life is 6 hours
During the first six hours, we have a mass of 60 mg left
In the next 6 hours, which is the second half-life, we have 30 mg left
In the next 6 hours, which is the third half-life, we have 15 mg left
Now, for the next 5 hours, there will not be a complete decay
Thus, we get the decay constant using the following:
[tex]\begin{gathered} t_{\frac{1}{2}}\text{ = }\frac{0.693}{k} \\ \\ 6\text{ = }\frac{0.693}{k} \\ \\ k\text{ = }\frac{0.693}{6}\text{ = 0.1155 h}^{-1} \end{gathered}[/tex]Mathematically:
In a combustion reaction, acetylene (C2H2) combines with oxygen gas to form carbon dioxide and water. Write and balance the equation for this reaction.Help me please
A complete combustion reaction like the one you mention is a reaction that will produce carbon dioxide and water using oxygen as the oxidizing agent. The fuel can vary and from there different numbers of CO2 and water will be obtained. Let us first write what the reaction would be taking into account the unbalanced reactants and products:
[tex]C_2H_2+O_2\rightarrow CO_2+H_2O[/tex]Now, to balance the equation we must count the number of atoms of each element on each side of the reaction.
In the previous scheme, we see that neither the carbon nor the oxygen are balanced, we can start by balancing the carbon. We have two carbon atoms in the reactants, so we put the coefficient two in front of the CO2 molecule.
I will be updating the scheme as I describe the procedure so that you are aware of it.
Now we must balance the oxygen, we have 5 atoms in the products and two in the reactants. To balance it, since we have an odd number in the products, we must adjust it to an even number. We place coefficient 2 in front of the H2O molecule. We have 6 oxygen atoms in the products, to have 6 oxygen atoms in the reactants we must place the coefficient 3 in front of the O2 molecule.
Now we have 6 oxygen atoms on each side of the reaction, we continue now with hydrogen. We have 4 hydrogens in the reactants, so we put the coefficient 2 in front of the C2H2 molecule.
Now the hydrogen is balanced, but the number of carbons changed and we must balance them again. We place the coefficient 4 in the CO2 molecule, so we will have 4 carbons on each side of the reaction.
In doing so, the number of oxygens was modified, so to finally have a balanced reaction we put the coefficient 5 in the O2 molecule to have 10 oxygen atoms on each side.
So, the balanced reaction will be:
[tex]2C_2H_2+5O_2\rightarrow4CO_2+2H_2O[/tex]What is an example of a chemical change that happens inside your body?
Let us first clarify the difference between a chemical process and a physical process.
In a physical process to a modification of the chemical structure of the molecule, either by breaking or because it is coupled to another molecule.
In a chemical process, the structure at the molecular level is not affected, this can be, for example, a reduction in size at the macro level, that a substance is transported from one place to another.
Now, looking at the three options that show us, we have three physical processes.
1. The first option corresponds to a displacement of food, this is a physical process.
2. The second option is a macro level size reduction, also a physical process.
4. The fourth option is an adsorption process, this can be a physical process or a chemical process, but in this case, the molecules of a substance adhere to the walls of the intestine without changing its chemical nature, so it will be a physical process.
3. Now, the third option is the breakdown at the molecular level of the food using enzymes, this is a chemical reaction, so it is a chemical process and this will be the answer.
Answer: Food being broken down by enzymes in your stomach
With all the steps please!For a 0.2 M aqueous solution of sodium hydroxide, calculate the following:a) pHb) pOHc) [H+]d) [OH-]
Answer:
a) pH= 13.3
b) pOH= 0.7
c) [H+]= 5.01*10^-14M
d) [OH-]= 0.2M
Explanation:
The formula of sodium hydroxide is NaOH. In the molecule there are Na+ ions and OH- that dissociates like this:
[tex]\text{ NaOH}\rightarrow\text{ Na}^++\text{ OH}^-[/tex]That means that 1 mole of NaOH dissociates into 1 mole of Na+ ions and 1 mole of OH-.
So, for a 0.2M solution, 0.2 moles of NaOH will dissociate into 0.2 moles of Na+ ions and 0.2 moles of OH-.
d) [OH-]
From the dissociation of NaOH we know that the concentration of OH- is [OH-]=0.2M.
b) pOH
With the concentration of OH-, we can calulate the pOH:
[tex]\begin{gathered} pOH=-log\lbrack OH^-] \\ pOH=-log(0.2) \\ pOH=0.7 \end{gathered}[/tex]So, the pOH is 0.7.
a) pH
Knowing the pOH and the following formula, we can calculate the pH of the solution:
[tex]\begin{gathered} pH+pOH=14 \\ pH+0.7=14 \\ pH=14-0.7 \\ pH=13.3 \end{gathered}[/tex]The pH of the solution is 13.3.
c) [H+]
Now that we know thw pH of the solution, we can calculate the concentration of H+:
[tex]\begin{gathered} pH=-log\lbrack H^+\rbrack \\ 13.3=-log\lbrack H^+\rbrack \\ 10^{(-13.3)}=\lbrack H^+\rbrack \\ 5.01*10^{-14}=\lbrack H^+\rbrack \end{gathered}[/tex]So, the concentration of H+ is 5.01*10^-14M.
What is the balanced chemical equation for the decomposition of mercury (II) oxide?
So,
The balanced chemical equation for the decomposition of mercury (II) oxide is:
Consider the neutralization reaction2 HNO3(aq) + Ba(OH)₂ (aq) -> 2 H₂O(l) + Ba(NO3)₂(aq)A 0.125 L sample of an unknown HNO, solution required 42.7 mL of 0.100 M Ba(OH)₂ for complete neutralization. What isthe concentration of the HNO, solution?
Answer:
C = 0.068 M
Explanation:
We are given: volume of HNO = 0.125 L
: volume of Ba(OH)2 = 42.7 mL
: concentration of Ba(OH)2 = 0.100 M
We first determine the number of moles of Ba(OH)2:
n = CV
Where: n is number of moles, C is concentration, and V is volume
n = CV
= 0.0427 * 0.100
= 0.00427 mol
From the balanced equation:
n(HNO3) = 2 * n(Ba(OH)2)
= 2 * 0.00427
= 0.00854
For HNO3:
C = n/V
= 0.00854/0.125
= 0.068 M
Aspirin is a common analgesic. If you want to produce 500. mg of aspirin (C9H8O4, m.w. = 180.16 g/mol) from the reaction of C7H6O3 (m.w. = 130.12 g/mol) and C4H6O3 (m.w. = 102.09 g/mol), what is the minimum amount of C4H6O3 that is needed?2C7H6O3(s) + C4H6O3(l) → 2C9H8O4(s) + H2O(l)
1) First, let's rewrite the chemical equation here:
2 C7H6O3(s) + C4H6O3(l) → 2 C9H8O4(s) + H2O(l)
2) Let's find out how many moles of C9H8O4 have into 500 mg of it. For this, use ese the following equation:
mole = mass/ molar mass
mass = 500 mg = 0.5 g
molar mass of C9H8O4 = 180.16 g/mol (the question give it to us)
mole = 0.5/180.16
mole = 0.0028 moles of C9H8O4
3) Using the chemical equation proportion, we can discover the amount in moles of C4H6O3 needed to form 0.0028 moles of C9H8O4. So:
1 mol of C4H6O3 forms 2 moles of C9H8O4
x mol of C4H6O3 forms 0.0028 moles of C9H8O4
2x = 0.0028
x = 0.0014 moles of C4H6O3
4) We need to find the answer in grams. Let's transform 0.0014 moles of C4H6O3 into grams. For this, use ese the following equation:
mass = mole × molar mas
mass = 0.0014 moles × 102.09
mass = 0.142 grams or 1.42x10⁻¹
Answer: The amount of C4H6O3 that is needed is 1.42x10⁻¹ g.
Fermentation is the process by which yeast acts upon a sugar in an oxygen-free environment to produceQuestion 9 options:A) amines.B) carboxylic acids.C) alcohols.D) esters.
Answer
Alcohol
Explanation
Alcoholic fermentation is a biochemical process in which yeast and some kinds of bacteria convert sugars into ethyl alcohol and carbon dioxide.
Please help me figure out how to do this question
Given that molar molar enthalpy of combustion of cyclohexanone is -3468.1 kJ/mol when liquid water is formed, what is the molar enthalpy of formation of cyclohexanone?
What is the volume of 0.110 g of C2H2F4 vapor at 0.887 atm and 34.0°C?Answer in units of L.Leave all the numbers after the decimal point (No usage of significant figures)
Assume that C₂H₂F₄ vapor is an ideal gas and use the ideal gas law to find the volume of the vapor.
First, use the molecular mass of the compound to find the number of moles present in 0.110g of the compound.
[tex]0.110g\cdot\frac{1mol}{102.03g}=0.00108mol[/tex]Convert the temperature in celsius to kelvin:
[tex]K=34+273.15=307.15[/tex]Use the ideal gas law and solve it for V:
[tex]\begin{gathered} P\cdot V=n\cdot R\cdot T \\ V=\frac{n\cdot R\cdot T}{P} \end{gathered}[/tex]Replace for the known values (R, the ideal gas constant is 0.082 atmL/molK):
[tex]\begin{gathered} V=\frac{0.00108mol\cdot0.082\frac{atmL}{molK}\cdot307.15K}{0.887atm} \\ V=0.0306L \end{gathered}[/tex]The volume of the vapor is 0.0306L.
The combining of hydrogen and oxygen gas into liquid water is an example of which type of change?
The combining of hydrogen and oxygen gas into liquid water is an example of which type of change physical change.
A physical change occurs when hydrogen and oxygen are combined to create water. Concrete breaking up is a physical change. A chemical change occurs when beach sand would be washed out to sea.
When hydrogen will react with oxygen then it will form water. It is a kind of combination reaction. Its chemical reaction can be expressed as:
H2 + O2 → H2O
Therefore, this reaction is an example of physical change.
To know more about physical change
https://brainly.com/question/17931044
#SPJ1
During her presentation, Zahara was asked several questions from the audience and to provide the molecular formula for molecules that the audience had questions about. Help Zahara classify whether the following items are an element, a compound, a homogenous mixture, or a heterogenous mixture: Iron
Iron is an element.
This is because Iron consists of a single type of atom.
Which of the following is an example of engineering, not science?
A. Designing a radiation containment system
B. Observing the effect of radiation on photographic film
C. Determining the effects of radiation on plants
D. Studying different types of radiation
Answer:
A. Designing a radiation containment system
Explanation:
Engineers invent, create, design, and maintain machines, building/structures, and software data.
9) Determine the molecular formula for ibuprofen, a common headache remedy.
Ibuprofen contains a percent composition of 75.7% C, 8.80% H and 15.5% O
and has a molar mass of 206g/mole.
Ibuprofen has a molecular formula of C13H18O2, meaning it has 13 carbon atoms, 18 hydrogen atoms, and 2 oxygen atoms.
The molar mass of ibuprofen (206 g/mol) is determined by adding up the atomic masses of each element in the molecule:
C (12.01 g/mol) + H (1.01 g/mol) + O (16.00 g/mol) = C13H18O2
Ibuprofen's percent composition (75.7% C, 8.80% H, 15.5% O) can be used to determine the number of each type of atom in the molecule:
13 C atoms x 100% = 75.7% C
8.80 H atoms x 100% = 8.80% H
15.5 O atoms x 100% = 15.5% O
Thus, ibuprofen has 13 carbon atoms, 8 hydrogen atoms, and 15 oxygen atoms.
To know more about antacids, click below:
https://brainly.com/question/13102012
#SPJ1
You could add HCl(aq) to the solution to precipitate out AgCl(s) . What volume of a 0.100 M HCl(aq) solution is needed to precipitate the silver ions from 16.0 mL of a 0.160 M AgNO3 solution?Express your answer with the appropriate units.
The volume of a 0.100 M solution needed is 256 mL.
A chemical reaction, the transformation of one or more chemicals (the reactants) into one or more distinct compounds (the products). Chemical elements or chemical compounds make up substances.
From the question,
The chemical reaction is:
AgNO₃ + HCl → AgCl + HNO₃
The volume of silver ions is V = 16 mL = 0.16 L
Concentration of AgNO₃, c( AgNO₃ ) = 0.160 mol/L
Moles of AgNO₃, n( AgNO₃ ) = 0.16L × 0.160 mol/L = 0.0256 mol
From the reaction,
n( AgNO₃ ) : n( HCl ) = 1 : 1
0.0256 : n( HCl ) = 1 : 1
Therefore,
n( HCl ) = 0.0256 mol
The volume of hydrochloric acid is:
V( HCl ) = n( HCl ) ÷ c( HCl )
V( HCl ) = 0.0256 mol ÷ 0.100 mol/L
V( HCl ) = 0.256 L
V( HCl ) = 256 mL
Learn more about volume here:
brainly.com/question/27100414
#SPJ9
Which of the following statements is true of the internal energy of a system and its surroundings during an energy exchange with a negative ∆Esys?
a. The internal energy of the system and the surroundings increases
b. The internal energy of the system and the surroundings decreases.
c. The internal energy of the system increases and the surroundings decreases.
d. The internal energy of the system decreases and the surroundings increases.
The system's internal energy decreases while the environment's internal energy rises (option -D) is correct answer.
What is the definition of a system's internal energy?The internal energy of a system with specific boundaries is composed of the kinetic energy produced by the motion of molecules, the potential energy produced by the vibrational motion, and the electric energy of atoms within molecules. These three types of energy are added together.
The internal energy is equivalent to the system's heat. Since heat is neither created nor destroyed, as the environment's heat level rises, so does the system's heat level.
The gas's state is the only factor that influences its internal energy. In an isothermal process, the volume graph of the change in internal energy in the maximum area under pressure equals the heat supplied in any process. Work is dependent on state but not on a path.
To know more about internal energy of a system visit:
https://brainly.com/question/11742607
#SPJ1
The state of matter that has an indefiniteshape, indefinite volume, and highcompressibility isA. solidB. liquidC. gas
Answer:
Explanation:
Here, we want to answer a question of state of matter
While solids have a definite shape and are incompressible under normal conditions, liq
17.Which of the following is a weak acid?Select one:a. Acetic acidb. Hydrochloric acidc. Nitric acidd. Sulfuric acid
ANSWER
A. acetic acid is a weak acid
how does energy and intermolecular forces affect water evaporation.
Evaporation is a phenomenon in which atoms of substances in a liquid state obtain enough energy to change to a gaseous state. The movement caused by the temperature of the molecules must be sufficient to overcome the surface tension of the substances and achieve the evaporation process. The molecules must have enough energy to
break intermolecular interactions and go to the gaseous state. Breaking up intermolecular interactions requires energy, which is usually given through heat. Therefore, this process is an endothermic reaction.
Fill in the chart to identify three parts of Dalton's model of the atom.
The first part of Dalton's model is that all matter is made of atoms, and these atoms are indivisible.
The second part of this model is that atoms of an element have identical masses and identical propertes.
At last, the third part of Dalton's model is that all compounds are formed by two or more different type of atoms combined.
Imagine two different substances that are both pure, meaning they each contain only one
type of matter. Each substance has a different temperature.
Which two properties determine which substance has the higher temperature?
the mass of one particle in each substance
the average speed of the particles in each substance
the speed at which each substance is moving
the kinetic energy of the slowest particle in each substance
two different substances that are both pure, meaning they each contain only one type of matter. two properties determine which substance has the higher temperature is the kinetic energy of the slowest particle in each substance
What are the types of energy ?The energy can be defined as ability to work or produce action and / or movement and manifests itself in many different ways, such as body movement, heat, electricity, etc.
The different types of energy include Kinetic energy which is associated with the movement of bodies. Potential energy which is stored by virtue of a body's position relative to its surface is also called gravitational potential energy.
Thermal Energy or Heat can be defined as the energy associated with the kinetic energy of the molecules that make up an element, it can be manifested if there is a temperature difference between two bodies.
For more details regarding energy, visit
brainly.com/question/28869293
#SPJ1
A newly discovered element, X, has been found to have the isotopes listed below (with masses and % abundances). Calculate the average atomic mass.
ISOTOPE
MASS (amu)
%
ABUNDANCE
15.0
21.0
64.0
71x
75x
77x
71.007
74.996
77.112
Type your answer.....
Average atomic mass of newly discovered element X is 166
What is average atomic mass?
It is calculated by adding the masses of the element's isotopes each multiplied by its natural abundance on Earth
Given data
Isotope Mass % abundance
15 71 71.007
21 75 74.996
64 77 77.112
Contribution made by each isotope by multiplying natural abundance with mass
Average atomic mass
= (71 × 71.007 + 75 × 74.996 + 77 × 77.112) / 100
= 166
Therefore average atomic mass is 166
Learn more about Average atomic masses at https://brainly.com/question/24666479
#SPJ13
Determine the mixture in equimolar quantities, if the PH is equal to, less than or greater than 7.A) A weak base and a strong acidB) a strong Base and a strong acidC) A strong base and an acid
We need to determine how is the PH in the given mixtures:
A) A weak base and a strong acid:
Acid and base react to form an acidic solution and, being acidic, this results in a solution with a pH lower than 7
B) A strong base and a strong acid:
When mixing a strong base and a strong acid, neutralization occurs, that is, a neutral pH or equal to 7 is obtained
C) A strong base and acid:
If we have a weak acid, when adding a strong base the pH approaches neutrality without sudden changes, but once the acid has been neutralized, just add a few drops of excess soda to obtain a sudden increase in pH as if there were only base. free. In this case, at the equivalence point the pH> 7
ANSWER:
A) Less than 7
B) Equal to 7
C) Greater than 7
A gas sample has 1.65 moles and occupies 3.50 L. What volume will it occupy with 2.60 moles?
answer and explanation
Given:
V1 = 3.50 liters
n1 = 1.65 mols
n2 = 2.60 mols
V2 = unknown
solution
to determine the volume that will be occupied by 2.60 mols we can use to following equation
V1/V2 = n1/n2
and we can rearrange the equation to make V2 subject of the formula like so:
V2 = V1n2/n1
= 3.50L x 2.60mols/1.65 mols
= 5.5 liters
2.60 mols will occupy a volume of 5.5 liters
Describe the bonding in aluminium
• +Aluminium forms a non- directional metalic bond.
• (bonding in chemistry is the lasting attraction between atoms , ions or molecule )... think of it like joining together of particles / elements
,• This type of covalent bonding results in a metallic lattice structure.
• Since aluminium is a metallic solid, the maximum covalency of aluminium is three only.
See the drawing below:
How many neutrons are found in the element Al?
Answer:Neutron = 27 – 13 = 14. Therefore, an aluminum atom has fourteen neutrons. Based on the atomic number, mass number, and neutron number of the element, three things can be considered.
Explanation:
What mass of H atoms is contained in 50.7 g
of NH3?
Answer in units of g.
The mass of hydrogen present in 50.7 grams of ammonia is equal to 8.95 g.
What is a mole?A mole is a scientific unit that is used to determine the huge number of quantities of atoms, molecules, ions, etc. The mass of the 1 mole of any element is called atomic mass and that of one mole of any compound is called molar mass.
The number of entities present in 1 mole was found to be equal to 6.023 × 10 ²³ per mole which is known as Avogadro’s constant.
Given, the mass of ammonia = 50.7 g
The mass of the one mole of ammonia = 17 g/mol
17 g of ammonia contain the mass of hydrogen = 3 g
50.7 g of ammonia contains a mass of hydrogen = (3/17) × 50.7 = 8.95 g
Learn more about the mole, here:
brainly.com/question/26416088
#SPJ1
Fill in the table with the volume of each sample. Use the periodic table to find the molar mass of each molecule. Then calculate the mass of the gas in each balloon.Periodic TableFirst, compare the two oxygen samples. Consider how volume relates to the number of moles. Now compare the two gases with the same volume. Is there a relationship between volume and mass?
1) First let's calculate the molar mass of O₂ and H₂:
O₂: (16x2) = 32 g/mol (for both oxygen 1 and 2)
H₂: (1x2) = 2 g/mol
2) Now let's calculate the mass of gas sample (g) of:
Oxygen 1:
mass = mole x molar mass
mass = 1 x 32 = 32 g
Mass of Oxygen 1: 32 g
Oxygen 2:
mass = mole x molar mass
mass = 2 x 32 = 64 g
Mass of Oxygen 2: 64 g
Hydrogen:
mass = mole x molar mass
mass = 1 x 2 = 2 g
Mass of Hydrogen: 2 g
For the two oxygen samples, if the number of moles double, the mass double and the volume also double.
But the two gases of the same volume have different masses (Hydrogen 2 g and
oxygen 32 g). So there is no relationship between volume and mass for different gases.
Calculate the [OH−] of each aqueous solution with the following [H3O+]:blood, 4.5×10−8M
Answer
2.22 x 10⁻⁷ M
Procedure
To calculate the [OH⁻] concentration of blood we will consider the following pH formulas
pH=-log [H₃O⁺]
pH+pOH=14
The pH of blood will be
[tex]pH=-\log_{10}[4.5\times10^{-8}M]=7.3467[/tex]Then we do the rest
[tex]pOH=14-7.3467=6.6532[/tex]Lastly, we transform from pOH to concentration
[tex][OH^-]=10^{-pOH}=10^{-6.6532}=2.22\times10^{-7}[/tex]an element with the valence electron configuration 3s2 3p2 belongs to group
Answer:
Group 4A (Group IVA)
The answer is B
Explanation:
An element with valence electron configuration:
[tex]3s^23p^2[/tex]has 4 valence electrons.
Since the valence shell is n = 3 it is in Period 3. Since there are 4 valence electrons (2 in 3s and 2 in 3p) it is in Group 4A