if a=1/2(a+b)h,express a in terms of A,b and h. pls solve with step by step
Answer:
[tex] a = \frac {2A - bh}{h} [/tex]
Explanation:
Given the following mathematical expression;
A = ½(a + b)h
To make a the subject of formula (express a in terms of A, b and h);
First of all, we would cross-multiply;
2A = (a + b)h
Opening the bracket, we have;
2A = ah + bh
Rearranging the mathematical expression, we have;
ah = 2A - bh
[tex] a = \frac {2A - bh}{h} [/tex]
If an object has a mass of 243.8 g and occupies a volume of 0.125L, what will be the density of this object in gm/cm3?
Answer:
it might reach to 4g per L
When sodium chloride, NaCl , dissolves in water, the solution contains ___________________ in addition to the water solvent. The partial charges in water help dissolve the compound as the hydrogen end of water is attracted to the ____________ and the oxygen end is attracted to the _______________
Answer:
sodium ions and chloride ions
chloride ion
sodium ion
Explanation:
Ionic substances are composed of ions. When you dissolve an Ionic substance in water, the ions that compose the substance together with water molecules are present in solution.
Hence, when sodium chloride is dissolved in water, sodium ions and chloride ions are released in solution.
Water has a dipole moment. Hence, the chloride ions are attracted to hydrogen (the positive end of the dipole) while sodium ions are attracted to oxygen (the negative end of the dipole).
This is how the solid is dissolved in water.
When sodium chloride, NaCl , dissolves in water, the solution contains sodium and chloride ions in addition to the water solvent. The partial charges in water help dissolve the compound as the hydrogen end of water is attracted to the chloride ions and the oxygen end is attracted to the sodium ions.
What molecules are soluble in water?Those molecules in which positive ion as well as negative ion is present, will show solubility in water.
Sodium chloride (NaCl) is an ionic compound, which dissociates into sodium ion and chloride ion in the water. As in the water H⁺ ions are present which get attracted towards the chloride ions (Cl⁻) and hydroxide ion (OH⁻ ion) get attracted towards the sodium ions (Na⁺) and show complete dissolution.
Hence correct answers are sodium and chloride ions, chloride ion and sodium ion.
To know more about solubility in water, visit the below link:
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Does a reaction occur when aqueous solutions of copper(II) nitrate and calcium chloride are combined
Answer:
Does a reaction occur when aqueous solutions of copper(II) nitrate and calcium chloride are combined?
Explanation:
The given reaction is an example of a chemical double displacement reaction.
The mutual interchange of the ions takes place.
The balanced chemical equation of the reaction is:
[tex]Cu(NO_3)_2(aq)+CaCl_2(aq) -> Ca(NO_3)_2(aq)+CuCl_2(aq)[/tex]
All the products formed are also highly soluble.
So, all the ions are spectator ions.
Hence, all will cancel with each other and ions remain in the net ionic equation and hence, the reaction does not take place.
A chemist combines 33 g of methane with 289 g of oxygen to from 189 g of carbon dioxide and 30 g of water. Determine if the results of the following word problem adheres to the Law of Conservation of Mass.
Answer:
The correct answer is - no not adhere to the law of mass conservation.
Explanation:
According to the law of mass conservation in an isolated system, the mass can not be created or destroyed and in a chemical or physical change, the mass of products should be always equal to the mass of reactants.
On the basis of the law the mass of the chemical reaction-
Mass of products = mass of reactants
33 g of methane + 289g of oxygen = 189g of carbon dioxide + 30g of water
322g ≠ 219 g
which means this reaction does not adhere to the law of conservation.
Using the boh model of a He ion, what transition is most likelu to result in the emission of radiation with a wavelength of approximately 274 nm
Answer:
[tex]n=6\ to\ n=3[/tex]
Explanation:
From the question we are told that:
Wavelength [tex]\lambda=274 *10^{-9}m[/tex]
Bohr's constant [tex]R = 1.097 × 10^7 / m (or m−1)[/tex]
Helium atom [tex]z=2[/tex]
Generally the equation for Wavelength is mathematically given by
[tex]\frac{1}{\lambda}=Rz^2(\frac{1}{nf^2}-\frac{1}{nf^2})[/tex]
[tex]0.083=(\frac{1}{nf^2}-\frac{1}{nf^2})[/tex]
Therefore
The Range of n fall at
[tex]n=6\ to\ n=3[/tex]
list four energy resources
Answer:
Nuclear
Solar
Wind
Hydro
Geo-Thermal
Explanation:
Solar energy from the sun.Geothermal energy from heat inside the earth.Wind energyBiomass from plants.hope it helps
stay safe healthy and happy....What are the concentrations of hydronium and hydroxide ions in a solution with pH 2.6?
Please help omg. Ive been stuck for 15 minutes
Answer:
The concentrations of hydronium and hydroxide ions in a solution with pH 2.6 are 2.51*10⁻³ and 3.98*10⁻¹² respectively.
Explanation:
pH is a measure of the acidity or alkalinity of an aqueous solution. The pH indicates the concentration of hydrogen ions present in certain solutions. Mathematically it is defined as the opposite of the base 10 logarithm or the negative logarithm of the activity of hydrogen ions, whose equation is
pH= -log [H⁺]
So, being pH= 2.6 and replacing in the definition of pH:
2.6= -log [H⁺]
[tex][H^{+} ]=10^{-2.6}[/tex]
[H⁺]=2.51*10⁻³
pOH is a measure of the concentration of hydroxide ions (OH⁻). The sum between the pOH and the pH results in 14:
pOH + pH= 14
So, being pH= 2.6:
pOH + 2.6= 14
pOH= 14 - 2.6
pOH= 11.4
The pOH is defined as the negative logarithm of the activity of the hydroxide ions. That is, the concentration of OH⁻ ions:
pOH= - log [OH⁻]
Being pOH= 11.4 and replacing
11.4= -log [OH⁻]
[tex][OH^{-} ]=10^{-11.4}[/tex]
[OH⁻]= 3.98*10⁻¹²
The concentrations of hydronium and hydroxide ions in a solution with pH 2.6 are 2.51*10⁻³ and 3.98*10⁻¹² respectively.
What is the
energy
2) The energy transition from n = 1 →n= 3 in hydrogen is 12.09 eV (1.6022 X 10J= 1 eV)-
of light emitted from n = 3 →n=1?
E e fiz
Answer:
energy is the ability to do work
What is unit? Write down the units of mass, temperature and power
Explanation:
a single thing, person, or group forming part of a whole There are 36 units in my apartment building. the least whole number : one. a fixed quantity (as of length, time, or value) used as a standard of measurement An inch is a unit of length.mass=kilogram (kg)
temperature=kelvin
power=watt
hope it helps
stay safe healthy and happy..Given 0.60 mol CO2, 0.30 mol CO, and 0.10 mol H20, what is the partial pressure of the CO if the total pressure of the mixture was 0.80 atm?
Answer:
Explanation:
/ means divided by
* means multiply
1. formula is
partial pressure = no of moles(gas 1)/ no of moles(total)
0.30 mol CO/0.60 mol CO2 + 0.30 mol CO + 0.10 mol H20 ->
.3/(.6+.3+.1) =
.3/1 =
.3 =
partial pressure of CO
2.
.3 * .8 atm = .24
khanacademy
quizlet
The partial pressure of the CO is 0.24 atm if the total pressure of the mixture was 0.80 atm.
Dalton's Law of Partial pressureDalton's Law of partial pressure states that the total pressure exerted by non reacting gaseous mixture at a constant temperature and given volume is equal to the sum of partial pressure of all gases.
Dalton's Law of partial pressure using mole fraction of gas
Partial pressure of carbon monoxide (CO) = Mole fraction of carbon monoxide (CO) × Total pressure
Now, we have to find the first mole fraction of CO
Mole fraction of carbon monoxide (CO) = [tex]\frac{\text{moles of solute}}{\text{total moles of solute}}[/tex]
= [tex]\frac{\text{moles of CO}}{\text{moles of CO}_2 + \text{moles of CO} + \text{moles of H}_{2}O}[/tex]
= [tex]\frac{0.30}{0.60 + 0.30 + 0.10}[/tex]
= [tex]\frac{0.30}{1}[/tex]
= 0.3
Now, put the value in above equation, we get that
Partial pressure of carbon monoxide (CO)
= Mole fraction of carbon monoxide (CO) × Total pressure
= 0.3 × 0.8
= 0.24 atm
Thus, the partial pressure of the CO is 0.24 atm is the total pressure of the mixture was 0.80 atm.
Learn more about the Dalton's Law of partial Pressure here: https://brainly.com/question/14119417
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Suppose you analyze a 30.3 g sample of bleach and determine that there are 2.61 g of sodium hypochlorite present. What is the percent of sodium hypochlorite in the bleach sample
Answer:
8.61 %
Explanation:
The percent of sodium hypochlorite in the bleach sample can be calculated using the following formula:
% of sodium hypochlorite = Mass of sodium hypochlorite / mass of sample * 100%We input the data given by the problem:
% of sodium hypochlorite = 2.61 g / 30.3 g * 100 % = 8.61 %I need help solving this!
For the reaction C + 2H2 → CH4, how many moles of hydrogen are needed to make 146.6 grams of methane, CH4 ?
Round your answer to the nearest tenth. If you answer is a whole number like 4, report the answer as 4.0
Use the following molar masses. If you do not use these masses, the computer will mark your answer incorrect.:
Element
Molar Mass
Hydrogen
1
Carbon
12
Answer: Moles of hydrogen required are 4.57 moles to make 146.6 grams of methane, [tex]CH_{4}[/tex].
Explanation:
Given: Mass of methane = 146.6 g
As moles is the mass of a substance divided by its molar mass. So, moles of methane (molar mass = 16.04 g/mol) are calculated as follows.
[tex]Moles = \frac{mass}{molar mass}\\= \frac{146.6 g}{16.04 g/mol}\\= 9.14 mol[/tex]
The given reaction equation is as follows.
[tex]C + 2H_{2} \rightarrow CH_{4}[/tex]
This shows that 2 moles of hydrogen gives 1 mole of methane. Hence, moles of hydrogen required to form 9.14 moles of methane is as follows.
[tex]Moles of H_{2} = \frac{9.14}{2}\\= 4.57 mol[/tex]
Thus, we can conclude that moles of hydrogen required are 4.57 moles to make 146.6 grams of methane, [tex]CH_{4}[/tex].
A student dropped a piece of nickel metal into a solution of HCl(aq). He observed the formation of gas bubbles and collected the gas into another test tube. The student performed a splint test and observed that the splint flared up when he placed the splint into the test tube of the gas. What can be said about the results of this students experiment?
a. The student performed the splint test incorrectly. He should of observed a popping sound when the splint was placed in the test tube.
b. The experiment was performed incorrectly. Nickel doesn't react with HCl. Therefore, the student picked up the wrong metal when conducting the experiment.
c. The student completed the experiment correctly and there were no errors in the experiment.
d. The student performed the splint test incorrectly. He should of observed the flame being extinguished when the splint was placed in the test tube.
Answer:
a. The student performed the splint test incorrectly. He should of observed a popping sound when the splint was placed in the test tube.
Explanation:
It is given that a student performed an experiment where he dropped a nickel metal in to HCl solution. He observed the reaction and performed a splint test in the test tube that is filled with a gas which is formed while Nickle is dropped into the solution of HCl.
But the experiment that the student performed was incorrect. He must have observed the popping sound when the splint was placed in the test tube.
When the splint was added to the gas splint flared up. The hydrogen gas pops out when exposed to the flame.
[tex]$Ni + HCl(aq) = NiCl + H_2$[/tex]
Thus the correct option is (a).
In the experiment "Preparation and Standardization of a Sodium Hydroxide Solution", why was the burette rinsed with NaOH before filling it to "zero" for the titration?
Answer: The correct option is ALL OF THE ABOVE.
Explanation:
TITRATION is a type of volumetric analysis which is used for determining the concentration of solutions. In this process a specific volume of a solution is placed in a conical flask by means of a pipette and small quantities of a second solution is slowly added from a burette until the end point is reached. This is determined by a means of an indicator which shows a characteristic colour change.
During titration, the following precautions should be followed to avoid errors and maintain standardisation in the experiment.
--> Any air bubble in the burette and pipette must be removed during measurement
--> the burette tap should be tightened to avoid leakage.
--> Remove the funnel from the burette before taking any reading to avoid errors in reading the volume.
--> use the base solution such as Sodium Hydroxide Solution to rinse the burette after washing with soap and tap water:
• to remove any air bubble and fill it's tip
• to remove any residual liquid from the water and soap solution which may interfere with the results of the experiment.
• to check if the burette is in good condition.
Therefore all of the above options to the question are correct.
determine the number of moles of Cl in 1.9 mol of CaCl2
Explanation:
In the formula of [tex]CaCl_2[/tex] we can see that there are 2mol Cl in 1 molecule of CaCl2. So, now we can do some math to find out how many mol of Cl there are in 1.9mol CaCl2!
[tex]1.9molCaCl_2*\frac{2molCl}{1molCaCl_2}[/tex]
So, there are 3.8mol Cl
Determine the kinds of intermolecular forces that are present in each element or compound. Part A KrKr Check all that apply. Check all that apply. dispersion forces dipole-dipole forces hydrogen bonding
Answer:
The kinds of intermolecular forces that are present in each element Kr-Kr.
Explanation:
Since Kr is an inert gas and in atomic form only it is highly stable.
So, Kr gas does not form molecules.
Between the atoms of inert gas, there exist London dispersion forces.
Hence, the intermolecular forces that are present between Kr-Kr atoms is London dispersion forces.
Que es la actividad física y en qué mejora
An atom has 20 electrons. Find out
i. It’s atomic numbers and total number of p-electrons
ii. The value of azimuthal quantum number (l) and magnetic quantum number (m) of the 19th electron of the atom.
iii. It’s group position in the periodic table.
Answer:
it's atomic number is 5 and total number is 10
The atom has an atomic number of 20 and has a total of 12 p electrons.
The azimuthal quantum number (l) of the 19th electron is 0 and the magnetic quantum number (m) of the 19th electron is 0.
It is an element of group 2
The number of electrons in the neutral atom is equal to the number of protons and is also the atomic number of an atom.
An atom is known to be electrically neutral. This is because the number of electrons in the atom is equal to the number of protons in the neutral atom.
The number of protons in the neutral atom is called the atomic number of the atom.
For an element that has 20 electrons, its electronic configuration is;
1s2 2s2 2p6 3s2 3p6 4s2.
The 19th electron is in the 4s orbital hence both the azimuthal and magnetic quantum numbers are zero.
The element has outermost electron configuration ns2 so it mus belong to group 2 of the periodic table.
https://brainly.com/question/16979660
The total entropy of a system and its surroundings always increases for a spontaneous process. This is a statement of
Answer:
second law of thermodynamics
Explanation:
According to the second law of thermodynamics, the total entropy of a system and its surroundings always increases for a spontaneous process.
Entropy is defined as the degree of disorderliness of a system. The entropy of a system never remains constant. It either increases or decreases in a process. The total entropy is the sum of the entropy of the system and its surrounding. The total entropy must increase in a spontaneous process.
Thus, the implication of this law is that even, if the entropy of a system decreases, this must be compensated for by increase in entropy of the surroundings in order for the process to be spontaneous.
A beaker is filled to the 500 mL mark with alcohol. What increase in volume (in mL) does the beaker contain when the temperature changes from 5° C to 30° C? (Neglect the expansion of the beaker, evaporation of alcohol and absorption of water vapor by alcohol.) The volume coefficient of expansion γγ for alcohol = 1.12 x 10-4 K-1
Answer:
"1.4 mL" is the appropriate solution.
Explanation:
According to the question,
[tex]v_0=500[/tex][tex]\alpha =1.12\times 10^{-4}[/tex][tex]\Delta \epsilon = 25[/tex]Now,
Increase in volume will be:
⇒ [tex]\Delta V = \alpha\times v_0\times \Delta \epsilon[/tex]
By putting the given values, we get
[tex]=1.12\times 10^{-4}\times 500\times 25[/tex]
[tex]=1.12\times 10^{-4}\times 12500[/tex]
[tex]=1.4 \ mL[/tex]
A chemical reaction occurring in a cylinder equipped with a moveable piston produces 0.601 mol of a gaseous product. If the cylinder contained 0.300 mol of gas before the reaction and had an initial volume of 2.16 L, what was its volume after the reaction
Answer:
4.33 L
Explanation:
Assuming ideal behaviour and that all 0.300 moles of gas reacted, we can solve this problem using Avogadro's law, which states that at constant temperature and pressure:
V₁n₂ = V₂n₁Where in this case:
V₁ = 2.16 Ln₂ = 0.601 molV₂ = ?n₁ = 0.300 molWe input the given data:
2.16 L * 0.601 mol = V₂ * 0.300 molAnd solve for V₂:
V₂ = 4.33 LNaCl is ___ formula of common salt
A. Empirical formula
B. Molecular formula
C. Both A and B
D. None of them
or each conjugate acid-base pair, identify the first species as an acid or base and the second species as the conjugate acid or base of the first. A) CH3COOH and B) CH3COO- A. is _____ B. is _________ C) CH3O- and D) CH3OH C. is _____ D. is _________
Answer:
A. an acid
B. a base
C. conjugate base
D. conjugate acid
Explanation:
This question appears incomplete because it is starting with a "or".
However, the available question can still be answered.
An acid (according to "Bronsted-Lowry") is a chemical compound/specie that can donate hydrogen ion(s) in a reaction while a base is the compound/specie that can receive hydrogen ion(s). From this definition, it can be deduced that CH₃COOH (ethanoic acid) is an acid (weak acid) because it can donate an hydrogen ion while CH₃COO⁻ is a base because it can receive a hydrogen ion.
Also, a conjugate acid is the compound formed when an acid has donated a hydrogen ion to a base (i.e it is a base with hydrogen ion attached to it) while a conjugate base is the acid that has lost it's hydrogen ion. Thus, the conjugate acid in the question is CH₃OH while the conjugate base in the question is CH₃O⁻.
A. an acid
B. a base
C. conjugate base
D. conjugate acid
Name two natural sources of esters.
Answer:
"Esters are widespread in nature and are widely used in industry. In nature, fats are in general triesters derived from glycerol and fatty acids. Esters are responsible for the aroma of many fruits, including apples, durians, pears, bananas, pineapples, and strawberries."
Explanation:
My question today is : The reaction of 11.9g go CHCl3 with excess chlorine produced 10.2g of CCl4, carbon tetrachloride. What is the percent yield
Answer:
66.7%
Explanation:
Step 1: Write the balanced equation
CHCl₃ + Cl₂ ⇒ CCl₄ + HCl
Step 2: Calculate the theoretical yield of CCl₄ from 11.9 g of CHCl₃
According to the balanced equation, the mass ratio of CHCl₃ to CCl₄ is 119.38:153.82.
11.9 g CHCl₃ × 153.82 g CCl₄/119.38 g CHCl₃ = 15.3 g CCl₄
Step 3: Calculate the percent yield of CCl₄
Given the experimental yield of CCl₄ is 10.2 g, we can calculate the percent yield using the following expression.
%yield = (exp yield/theo yield) × 100%
%yield = (10.2 g/15.3 g) × 100% = 66.7%
The table shows the nature of reactants and products formed in a certain type of chemical reaction.
Nature of Reactants and Products
Reactants
Metal + lonic compound
Products
Metal + lonic compound
Which of the following is true about the type of chemical reaction?
it is a single replacement reaction, and the anions in the two inic compounds are different.
It is a single replacement reaction, and the cations in the two ionic compounds are different.
It is a double replacement reaction, and the anions in the two ionic compounds are different.
It is a double replacement reaction, and the cations in the two ionic compounds are different.
Answer: It is true about the type of reaction that it is a single replacement reaction, and the cations in the two ionic compounds are different.
Explanation:
When one element in a compound is replaced by another element in a chemical reaction then it is called a single replacement reaction.
For example, [tex]K + NaCl \rightarrow KCl + Na[/tex]
Here, potassium metal is replacing the sodium metal in the sodium chloride compound.
As metals become cation by losing an electron in a chemical reaction.
Thus, we can conclude that it is true about the type of reaction that it is a single replacement reaction, and the cations in the two ionic compounds are different.
Answer: Its A
Explanation:
a single replacement reactions, and the ANIONS in the two ionic compounds are different
Can someone please please help
Answer:
oxidizer
Explanation:
an example of an oxidizers are oxygen and hydrogen peroxide
If a hydrogen atom and a helium atom have the same kinetic energy:________
a. the wavelength of the hydrogen atom will be about 4 times longer than the wavelength of the helium atom.
b. the wavelength of the hydrogen atom will be about 2 times longer than the wavelength of the helium.
c. the wavelength of the hydrogen atom will be roughly equal to the wavelength of the helium atom.
d. the wavelength of the helium atom will be about 2 times longer than the wavelength of the hydrogen atom.
e. the wavelength of the helium atom will be about 4 times longer than the wavelength of the hydrogen atom.
Answer: If a hydrogen atom and a helium atom have the same kinetic energy then the wavelength of the hydrogen atom will be roughly equal to the wavelength of the helium atom.
Explanation:
The relation between energy and wavelength is as follows.
[tex]E = \frac{hc}{\lambda}\\[/tex]
This means that energy is inversely proportional to wavelength.
As it is given that energy of a hydrogen atom and a helium atom is same.
Let us assume that [tex]E_{hydrogen} = E_{helium} = E'[/tex]. Hence, relation between their wavelengths will be calculated as follows.
[tex]E_{hydrogen} = \frac{hc}{\lambda_{hydrogen}}[/tex] ... (1)
[tex]E_{helium} = \frac{hc}{\lambda_{helium}}[/tex] ... (2)
Equating the equations (1) and (2) as follows.
[tex]E_{hydrogen} = E_{helium} = E'\\\frac{hc}{\lambda_{hydrogen}} = \frac{hc}{\lambda_{helium}} = E'\\\lambda_{helium} = \lambda_{hydrogen} = E'[/tex]
Thus, we can conclude that if a hydrogen atom and a helium atom have the same kinetic energy then the wavelength of the hydrogen atom will be roughly equal to the wavelength of the helium atom.
Water has a density of 1.00 g/mL. If you put an object that has a density of 0.79 g/mL into water, it will sink to the bottom.
ANSWER please
True
False
Answer:
False
Explanation:
An object with a density less than the density of water will float.
And an object that is denser than water (more than 1.00g/mL) will sink when placed in water.