Answer:
B₂O₃
Explanation:
Step 1: Calculate the mass of oxygen in 150 mg of boron oxide
Of 150 mg of boron oxide, 46.6 mg belong to boron. The mass of oxygen is:
150 mg - 46.6 mg = 103.4 mg
Step 2: Calculate the percent by mass of each element
We will use the following expression.
%Element = mElement/mCompound × 100%
%B = 46.6 mg/150 mg × 100% = 31.1%
%O = 103.4 mg/150 mg × 100% = 68.9%
Step 3: Divide each percentage by the atomic mass of the element
B: 31.1/10.81 = 2.88
O: 68.9/16.00 = 4.31
Step 4: Divide both numbers by the smallest one (2.88)
B: 2.88/2.88 = 1
O: 4.31/2.88 ≈ 1.5
Step 5: Multiply both numbers by 2 so that they are integers
B: 1 × 2 = 2
O: 1.5 × 2 = 3
The empirical formula is B₂O₃.
The speed limit on parts of the German autobahn was once set at 286 kilometers per hour (km/h). Calculate the speed limit in miles per hour (mph).
Answer: 178mph
Explanation:
From the question given, we are informed that the speed limit on parts of the German autobahn was once set at 286 kilometers per hour (km/h). Based on the information, the speed limit in miles per hour will then be:
= 286km/h × 1000m/1km × 1mi/1609m
= 178miles per hour
Therefore, the speed limit is 178mph.
Calculate the osmotic pressure of 5.0g of sucrose ssolution in 1L. Answer should be in Torr
Answer: The osmotic pressure of 5.0g of sucrose solution in 1 L is 271.32 torr.
Explanation:
Given: Mass = 5.0 g
Volume = 1 L
Molar mass of sucrose = 342.3 g/mol
Moles are the mass of a substance divided by its molar mass. So, moles of sucrose are calculated as follows.
[tex]Moles = \frac{mass}{molarmass}\\= \frac{5.0 g}{342.3 g/mol}\\= 0.0146 mol[/tex]
Hence, concentration of sucrose is calculated as follows.
[tex]Concentration = \frac{moles}{Volume (in L)}\\= \frac{0.0146 mol}{1 L}\\= 0.0146 M[/tex]
Formula used to calculate osmotic pressure is as follows.
[tex]\pi = CRT[/tex]
where,
[tex]\pi[/tex] = osmotic pressure
C = concentration
R = gas constant = 0.0821 L atm/mol K
T = temperature
Substitute the values into above formula as follows.
[tex]\pi = CRT\\= 0.0146 \times 0.0821 L atm/mol K \times 298 K\\= 0.357 atm (1 atm = 760 torr)\\= 271.32 torr[/tex]
Thus, we can conclude that the osmotic pressure of 5.0g of sucrose solution in 1 L is 271.32 torr.
Calculate the solubility (in mol/L) of Fe(OH)3 (Ksp = 4.0 x 10^-38) in each of the following situations:
(A) Pure water (assume that the pH is 7.0 and remains constant).
(B) A solution buffered at pH = 5.0.
(C) A solution buffered at pH = 11.0.
Answer:
(A) 1.962x10^-10 M solubility in pure water
(B) 4.0 x 10^-33 M solubility
(C) 4.0 x 10^-27 M solubility
Explanation:
(A) Fe(OH)3 would give (Fe3+) and (3OH-)
Ksp = [Fe^3+][OH-]^3 = 4.0 x 10^-38
Let y = [Fe^3+]
Let 3y = [OH-]
4x10^-38 = (y)(3y)^3
4x10^-38 = 27y^4
y^4 = 4x10^-38 ÷ 27
y^4 = 1.481 x 10^-39
y = 1.962x10^-10 M solubility in pure water
(B) pH = 5.0
5.0 = - log [OH-]
-5.0 = log [OH-]
[OH-] = 10^-5.0 = 1.0 x 10^-5 M
So, Ksp = [Fe^3+][OH-]^3 = 4.0 x 10^-38
[Fe^3+][1.0 x 10^-5] = 4.0 x 10^-38
[Fe^3+] = 4.0 x 10^-38 ÷ 1.0 x 10^-5
= 4.0 x 10^-33 M solubility
(C) pH = 11.0
11.0 = - log [OH-]
-11.0 = log [OH-]
[OH-] = 10^-11.0 = 1.0 x 10^-11 M
So, Ksp = [Fe^3+][OH-]^3 = 4.0 x 10^-38
[Fe^3+][1.0 x 10^-11] = 4.0 x 10^-38
[Fe^3+] = 4.0 x 10^-38 ÷ 1.0 x 10^-11
= 4.0 x 10^-27 M solubility
explain why the melting point of a solid is equal to the freezing point of it's liquid.
Explanation:
Because melting point and freezing point describe the same transition of matter, in this case from liquid to solid (freezing) or equivalently, from solid to liquid (melting). It is stuck on 0 ∘C during the entire melting or freezing process. None except melting is when you heat up and freezing when you cool down.hope it helps.stay safe healthy and happy.the ability of organism to sense changes in its body is an example of
Answer:
the ability of organism to sense changes in its body is an example of responsiveness.Hope it is helpful to you
Determine if the following statement is true or false, and why. “A hypothesis can be proven true.”
Answer:
True
Explanation:
A hypothesis can be proven true through experimentation. For example, if you hypothesize that a balloon with helium will float in the air, and then you test this and the balloon floats, you have just proven that your original hypothesis is true.
A hypnotist's watch hanging from a chain swings back and forth every 0.98 s. What is the frequency (in Hz) of its oscillation?
Answer:
1.02 Hz
Explanation:
frequency= (1/t) = (1/0.98) = 1.02 hz
The chemical formula is different from the empirical formula in
Answer:be careful and relax
Explanation:
Answer:
Hahaha be careful and relax
Classify each cation as a weak acid or pH neutral (neither acidic nor basic).
a. Na+
b. Ni2+
c. NH4+
Answer:
a. Na+ is pH neutral
b. Ni2+ = weak acid
c. NH4+ = Weak acid
Explanation:
To know the nature of the cation we need to find the nature of its conjugate base.
If the conjugate base of the ion is a strong base, the ion is neutral.
If the conjugate base is a weak base, the ion is a weak acid:
a. Conjugate base Na+ = NaOH
Sodium hydroxide is a strong base:
Na+ is pH neutral
b. Conjugate base Ni²⁺: Ni(OH)2 is a weak base because is not completely soluble in water. That means:
Ni2+ = weak acid
c. Conjugate base NH4+: NH4OH. Weak base:
NH4+ = Weak acid
Senario: 2 years ago, a fruit was smuggled into California on a plane from an exotic, far away land. The homeowner saw that the fruit had maggots and tossed it into the backyard, hoping the seed would grow. The larvae hatched out and moved throughout the area. This fictitious insect will destroy fruit and has the possibility of spreading disease killing the trees. The insect consumes plants in the Prunus species of stone fruits? Look up the plant genus Prunus.
Discussion: The insect has spread over a large area of Southern California, discovered at UC Riverside. What steps would you do to control or eradicate the destructive exotic insect?
PLZ HELP THX WITH COLLEGE LEVEL EXPERICENCE
Answer:
The best existing methods of control—artemisinin-based drug treatment and insect control with chemical sprays and treated bednets—can reduce the burden of disease substantially, and can even eliminate the disease in some regions,
hope this will help you more
An oxygen atom with three missing electrons is released near the Van de Graaff generator. What is its energy in MeV at this distance
Answer:
(a) The potential near its surface is 45 * 10^6 V.
(b) The distance from which its center is the potential 1.00 MV is 45 m.
(c) Its energy in MeV when the atom is at the distance found in part b is 132 MeV.
Explanation:
Note: This question is not complete. The complete question is therefore provided before answering the question.
A research Van de Graaff generator has a 2.00-m diameter metal sphere with a charge of 5.00 mC on it. (a) What is the potential near its surface?
(b) At what distance from its center is the potential 1.00 MV?
(c) An oxygen atom with three missing electrons is released near the Van de Graaff generator. What is its energy in MeV when the atom is at the distance found in part b?
The explanation of the answer is now provided as follows:
(a) What is the potential near its surface?
Q = Charge on the generator = 5 mC = 5 * 10^(-3)C
r = Sphere radius = 2 / 2 = 1 m
k = Constant of the electric force = 9 * 10^(9) N . m^2 / C^2
Therefore, the electric potential of a point charge can be calculated as follows:
V = kQ / r
V = (9 * 10^9 * 5 * 10^(-3)) / 1 = 45 * 10^6 V
Therefore, the potential near its surface is 45 * 10^6 V.
(b) At what distance from its center is the potential 1.00 MV?
This implies the distance where the potential is 1 MV.
Since the electric potential of a point charge is as follows:
V = kQ / r
Therefore, we can solve for r and estimate it as follows:
R = kQ / V = (9 * 10^9 * 5 * 10^(-3)) / 1 * 10^6 = 45 m
Therefore, the distance from which its center is the potential 1.00 MV is 45 m.
(c) An oxygen atom with three missing electrons is released near the Van de Graaff generator. What is its energy in MeV when the atom is at the distance found in part b?
The link between the potential difference and electrical potential energy can be stated as follows:
ΔV = ΔU / q
Therefore, we have:
ΔU = qΔV = q(Va - Vb) = 3 * (45 – 1) = 132 MeV
Therefore, its energy in MeV when the atom is at the distance found in part b is 132 MeV.
At 298 K, AHO = -1652 kJ/mol and ASO = 0.097 kJ/(K•mol). What is the Gibbs
free energy of the reaction?
Based on the calculations, the Gibbs's free energy for this chemical reaction is equal to -1,680.906 kJ/mol.
Given the following data:
Enthalpy of reaction (ΔH°) = -1652 kJ/mol.Temperature = 298 K.Entropy of reaction (ΔS°) = 0.097 kJ/mol.What is Gibbs's free energy?Gibbs's free energy simply refers to the quantity of energy that is associated with a particular chemical reaction.
Mathematically, the Gibbs's free energy for this chemical reaction can be calculated by using this formula:
ΔG° = ΔH° - ΔS°
Substituting the given parameters into the formula, we have;
ΔG° = -1652 × 10³ - (298 × 0.097)
ΔG° = -1652 × 10³ - 28.906
ΔG° = -1,680.906 kJ/mol.
Read more on Gibbs's free energy here: brainly.com/question/18752494
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ype the correct answer in the box.
Calculate the density of the substance.
A sample of a substance has a mass of 4.2 grams and a volume of 6 milliliters. The density of this substance is grams/milliliter.
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Explanation:
here is your answer. Hope it helps
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:
https://brainly.com/question/16903071
A mixture is -
A. a pure substance made through chemical processes
B. a pure substance made through physical processes
C.
an impure substance made through chemical processes
D.
an impure substance made through physical processes
Answer:
C
Explanation:
an impure substance made through chemical process
A chemist measures the amount of iodine solid produced during an experiment. He finds that of iodine solid is produced. Calculate the number of moles of iodine solid produced. Round your answer to significant digits.
The question is incomplete, the complete question is:
A chemist measures the amount of iodine solid produced during an experiment. He finds that 8.31 g of iodine solid is produced. Calculate the number of moles of iodine solid produced. Round your answer to the correct number of significant digits.
Answer: The number of moles of solid iodine produced is 0.0327 moles
Explanation:
The number of moles is defined as the ratio of the mass of a substance to its molar mass. The equation used is:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] ......(1)
Given mass of solid iodine = 8.31 g
Molar mass of solid iodine = 253.8089 g/mol
Plugging values in equation 1:
[tex]\text{Moles of solid iodine}=\frac{8.31g}{253.8089g/mol}=0.0327mol[/tex]
Hence, the number of moles of solid iodine produced is 0.0327 moles
Methanal is the simplest aldehyde, with one carbon atom. Draw the structural model for methanal (using C and H).
[tex] {\bold{\red{\huge{\mathbb{QUESTION}}}}} [/tex]
Draw the structural model for methanal (using C and H and O).
[tex] \huge\mathbb{\red A \pink{N}\purple{S} \blue{W} \orange{ER}}[/tex]
First place the C and then make a double bonded O atom with it then fill H to complete all valence spaces
How to calculate the actual volume (ml) of water removed from the burette with water
density 1 g/ml:
i. 5mL of water removed
Answer:
Explanation:
The density of pure water is 1 gram per 1 milliliter or one cubic cm. By knowing the density of water we can use it in dilution equations or to calculate the specific gravity of other solutions.
It can also help us determine what other substances are made of using the water displacement experiment. This is done by observing how much water is displaced when an object is submerged in the water. As long as you know the density of the water, the mass of the object being submerged and the volume of increase you can calculate the density of the object.
This was done by the great Archimedes in discovering what composed the kings crown.
A piece of solid tin is submerged in silver nitrate solution a reaction occurs producing tin(IV) nitrate solution and solid silver
Write a word equation write a skeleton equation write a balanced chemical equation
Answer:
Tin + silver trioxonitrate V -------->Tin IV nitrate + silver
Explanation:
The term word equation refers to an equation in which the reactants and products are written in words rather than chemical symbols.
Note than tin is above silver in the electrochemical series hence silver will be displaced by tin as follows;
Tin + silver trioxonitrate V -------->Tin IV nitrate + silver
what is the mass of insoluble calcium phosphate produced from .555 grams of calcium chloride
Answer:
0.518 g
Explanation:
Step 1: Write the balanced equation
3 CaCl₂ + 2 H₃PO₄ ⇒ Ca₃(PO₄)₂ + 6 HCl
Step 2: Calculate the moles corresponding to 0.555 g of CaCl₂
The molar mass of CaCl₂ is 110.98 g/mol.
0.555 g × 1 mol/110.98 g = 5.00 × 10⁻³ mol
Step 3: Calculate the moles of Ca₃(PO₄)₂ produced
5.00 × 10⁻³ mol CaCl₂ × 1 mol Ca₃(PO₄)₂/3 mol CaCl₂ = 1.67 × 10⁻³ mol Ca₃(PO₄)₂
Step 4: Calculate the mass corresponding to 1.67 × 10⁻³ moles of Ca₃(PO₄)₂
The molar mass of Ca₃(PO₄)₂ is 310.18 g/mol.
1.67 × 10⁻³ mol × 310.18 g/mol = 0.518 g
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]
Compound X has the same molecular formula as butane but has a different boiling point and melting point. What can be concluded about Compound X?
A It is a four-carbon alkene or alkyne.
B It is an optical isomer of butane.
C It is a geometric isomer of butane.
D It is a structural isomer of butane.
need this for gradpoint:)
Answer:
d
Explanation:
For an ideal gas, classify the pairs of properties as directly or inversely proportional. You are currently in a sorting module. a. P and n b. V and n c. P and T d. T and V e. P and V1. directly proportional2. inversely proportional
Answer:
the result for the following are (a) P is directly proportional to n
(b) V is directly proportional to T (c) P is directly proportional to T (d) T is inversly proportional to V (e) P is inversely proportional to V
An ice freezer behind a restaurant has a freon leak, releasing 47.97 g of C2H2F3Cl into the air every week. If the leak is not fixed, how many kilograms of fluorine will be released into the air over 6 months
Answer:
0.554 kg
Explanation:
We want to find the amount of kilograms of fluorine that will be released into the air over 6 months.
Let's convert to weeks to get;
6 × 4 = 24 weeks
Let's find Mass leak rate of fluorine from the formula;
Mass leak rate = (fluorine mass in freon/molar mass of freon) × leak rate
Molar mass of freon = ((12 × 2) + (1 × 2) + (19 × 3) + (35.5)) = 118.5 g/mol
Thus;
Mass leak rate = ((19 × 3)/(118.5)) × 47.97 = 23.074 g/week
Total fluorine leaked in 6 months = 24 × 23.074 = 553.776 g = 0.554 kg
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.
the question is in the attachment
Answer:
About redox reaction which of the given statements are true?
Explanation:
Redox reaction is the one in which both oxidation and reduction reactions take place simultaneously.
For example:
[tex]C(s)+O_2(g)->CO_2(g)[/tex]
In this reaction, carbon undergoes oxidation and oxygen undergoes reduction simultaneously.
During this reaction, mutual exchange of electrosn take place between the oxidant and the reductant.
Among the given options,
Option B. electrons are transferred
and
option C.They include both oxidation and reduction takes place are the correct answers.
Which of the following was NOT explained by Dalton's atomic theory?
ANSWER:
A. the Law of Multiple Proportions
B. the difference between elements and compounds
C.?the difference between isotopes of an element
D. the Law of Conservation of Mass
Answer:
A. the Law of Multiple Properties
Answer:
A. the law of multiple proportions
Write an equilibrium expression for each chemical equation involving one or more solid or liquid reactants or products.
Answer:
a.
[tex]Keq=\frac{[HCO_3^-][OH^-]}{[CO_3^{2-}]}[/tex]
b.
[tex]Keq=[O_2]^3[/tex]
c.
[tex]Keq=\frac{[H_3O^+][F^-]}{[HF]}[/tex]
d.
[tex]Keq=\frac{[NH_4^+][OH^-]}{[NH_3]}[/tex]
Explanation:
Hello there!
In this case, for the attached reactions, it turns out possible for us to write the equilibrium expressions by knowing any liquid or solid would be not-included in the equilibrium expression as shown below, with the general form products/reactants:
a.
[tex]Keq=\frac{[HCO_3^-][OH^-]}{[CO_3^{2-}]}[/tex]
b.
[tex]Keq=[O_2]^3[/tex]
c.
[tex]Keq=\frac{[H_3O^+][F^-]}{[HF]}[/tex]
d.
[tex]Keq=\frac{[NH_4^+][OH^-]}{[NH_3]}[/tex]
Regards!
Answer True or False for each of the following statements. (a) The carburization surface was maintained at slightly less than 0.25 wt% carbon for each specimen. (b) Comparing the finished specimens at a depth of 0.20 mm, specimen A features the lowest carbon concentration. (c) Comparing the finished specimens as a whole, specimen D features the lowest overall amount of carbon.
Answer:
verdadero/a
falso/b
verdadero/c
Explanation:
Pls pls pls help me
