Answer:
The answer is 1385 x10∧ -3
Explanation:
Scientific notation is a quick way to represent a number using notation in exponential form or powers of base ten.
This notation allows us to express too large or small numbers easily.
For example:
500 is written as 5x10∧2; Where the power 2 represents the number of 0's that follow 5.
0.0093 is written as 9.3x10∧-3; Where the power -3 represents the number of times the comma was moved to the right.
Americium-241 is an alpha emitter used in household smoke detectors and K-40 is a positron emitter used to date rock samples. The daughter nuclides in these two reactions are:
Answer:
Np-237, Ar-40.
Explanation:
Alpha particle is positively charged particle having a mass of 4 unit. Hence,when alpha is removed from any isotope it produces a element having mass 4 units less than original isotope that was before emission. Americium 241 isotopes used in the smoke detector which emit an alpha particle to produce neptunium-237.
Potassium-40 emits positron which is having negative charge to lower one proton and increase one neutron number in the particle and in such way it will produce [tex]^{40}Ar_{18}[/tex] not [tex]^{40}Ca_{20}[/tex]
Answer:
Neptunium - 237 , Argon - 40 .
Explanation:
Americium - 241 ⇒ Neptunium - 237 + alpha particles
²⁴¹₉₅Am ⇒ ²³⁷₉₃Np + ⁴₂α
K-40 ⇒ Argon 40 + positron .
⁴⁰₁₉K ⇒ ⁴⁰₂₀Ar + ₁e
Calculate the percent ionization of 1.60 M aqueous acetic acid solution. For acetic acid, Ka=1.8×10−5.
Answer:0.3348%
Explanation:
The rate constant for a reaction is 4.65 L mol-1s-1. What is the overall order of the reaction? zero
Answer:
second order
Explanation:
units of reaction and their order.
Zero order --> M^1 s^-1 = M/s
First order --> M^0 s^-1 = 1/s
Second order --> M^-1 s^-1 = L/mol s
In the question rate constant k = 4.65 L mol-1s-1. = 4.65 L/mol s
Hence, the reaction is a second order reaction
Answer:
The answer is "second".
Explanation:
Given:
rate constant for a reaction = 4.65 [tex]\frac{L}{mol \cdot s}[/tex]
[tex]\text{The rate of unit} = \frac{m}{s} \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ _{where} \ \ M=\frac{mol}{l} \\\\[/tex]
[tex]=\frac{mol}{l \cdot s}[/tex]
The orders unit value of the k
0 [tex]\frac{m}{s}[/tex]
1 [tex]\frac{1}{s}[/tex]
2 [tex]\frac{l}{m s}[/tex]
The rate of the unit is constant for the second-order that's why it is correct.
Calculate the pH after the addition of 10.0 mL of 0.240 M sodium hydroxide to 50.0 mL of 0.120 M acetic acid.
Answer:
pH = 4.58
Explanation:
The reaction of NaOH with acetic acid, CH₃COOH occurs as follows:
NaOH + CH₃COOH → CH₃COO⁻Na⁺ + H₂O
Moles that react:
NaOH = 10mL = 0.010L * (0,240mol / L) = 0.0024 moles NaOH
CH₃COOH = 50.0mL = 0.050L * (0.120mol / L) = 0.0060 moles CH₃COOH
That means after the reaction you will have:
CH₃COOH: 0.0060 mol - 0.0024 mol = 0.0036 moles
CH₃COO⁻Na⁺: 0.0024 moles
in solution, you will have the mixture of a weak acid (Acetic acid), with its conjugate base (sodium acetate, CH₃COO⁻Na⁺). And pH of this buffer can be determined using H-H equation:
pH = pKa + log [A⁻] / [HA]
For Acetic buffer pKa = 4.76:
pH = 4.76 + log [CH₃COO⁻Na⁺] / [CH₃COOH]
Where [] is molarity of each species or moles
Replacing:
pH = 4.76 + log [0.0024 moles] / [0.0036 moles]
pH = 4.58
How many dm³ of hydrogen,measured at s.t.p.,would be needed to reduce 47.7g of copper(II) oxide to copper?
A. 4.48
B. 6.72
C. 10.82
D. 13.44
help a friend please....will mark brainliest
Answer:
D. 13.44 dm³
Explanation:
Step 1: Write the balanced equation
CuO + H₂ ⇒ Cu + H₂O
Step 2: Calculate the mass corresponding to 47.7 g of CuO
The molar mass of CuO is 79.55 g/mol.
47.7 g × (1 mol/79.55 g) = 0.600 mol
Step 3: Calculate the moles of H₂ that react with 0.600 mol of CuO
The molar ratio of CuO to H₂ is 1:1. The moles of H₂ are 1/1 × 0.600 mol = 0.600 mol.
Step 4: Calculate the volume of 0.600 moles of H₂ at STP
1 mol of any gas at STP has a volume of 22.4 dm³.
0.600 mol × (22.4 dm³/1 mol) = 13.44 dm³
A particular brand of gasoline has a density of 0.737 g/mL at 25 ∘C. How many grams of this gasoline would fill a 13.6 gal tank (1US gal=3.78L)? Express your answer to three significant figures and include the appropriate units.
Answer:
Mass, m = 37900 grams
Explanation:
Given that,
The density of a brand of gasoline is 0.737 g/mL at 25°C
We need to find mass of gasoline would fill a 13.6 gal tank.
Density is defined as mass per unit volume.
We know that, 1US gal=3.78L
So,
1US gal = 3785.41 mL
13.6 US gal = 51481.6 mL
So,
[tex]d=\dfrac{m}{V}\\\\m=d\times V\\\\m=0.737\ g/mL\times 51481.6\ mL\\\\m=37941.93\ g[/tex]
or
m = 37900 g (in three significant figures)
So, the mass of the gasoline is 37900 grams.
Mass, m = 37900 grams
Given that,
The density of a brand of gasoline is 0.737 g/mL at 25°C
find the mass of gasoline would fill a 13.6 gal tank.
Density is defined as mass per unit volume.
We know that, 1US gal=3.78L
So,
1US gal = 3785.41 mL
13.6 US gal = 51481.6 mL
So,
[tex]Density=\frac{mass}{volume}\\\\0.737\ g/mL=mass/51481.6\ mL\\mass=37941.9392\ g[/tex]
or
m = 37900 g (in three significant figures)
So, the mass of the gasoline is 37900 grams.
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Which of these is the best hypothesis for why your tire's air pressure is low? If the pressure in the tire is low, then the tire lost air pressure because air is escaping through a hole in the tire. If the pressure in the tire is low, then someone let air out of the tire, because tires do not lose air naturally.
Answer:
If the pressure in the tire is low, then the tire lost air pressure because air is escaping through a hole in the tire.
Explanation:
The tire will lose air from a puncture in the tire, rather than the the second hypothesis saying tires do not lose air naturally.
Answer:
1) If the pressure in the tire is low, then the tire lost air pressure because air is escaping through a hole in the tire
Explanation:
I JUST DID IT
Heat is added to a substance, but its temperature does not rise. Which one of the following statements provides the best explanation for this observation? (a) the substance must be a gas. (b) the substance must be a non-perfect solid. (c) the substance undergoes a change of phase. (d) the substance has unusual thermal properties. (e) the substance must be cooler than its environment.
Answer:
C
Explanation:
Heat is added to a substance, but its temperature does not rise
because
(c) the substance undergoes a change of phase.
Does heat change during a phase change?Heat, which is energy, either comes into the material during a change of phase or heat comes out of the material during this change.
What are the four-phase changes of heat?Melting, Condensation, Vaporization & Sublimation
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convert 3427 into scientific notation
Answer:
[tex]3.427 \times {10}^{3} [/tex]
PLEASE HELP URGENT
>
Convert a speed of 857 mi/h to units of feet per minute. Also, show the unit analysis by dragging components into the
unit-factor slots.
Answer Bank
857 mi
Х
ih
()*(
60 min
12 in
1 min
1 mi
1 ft
5280 ft
3 ft
60 s
1h
60 h
857 mi/h =
ft
min
Answer:
75416 ft/min
(857 mi/h) x (5280 ft/h ÷ 1 mi / 1h ) x (1h x 1 ft ÷ 60 min x 1 ft)
Explanation:
Conversion of 857 mi/h to feet /second.
We'll begin by converting 857 mi/h to ft/h.
This is illustrated below:
Recall:
1 mi/h = 5280 ft/h
Therefore,
857 mi/h = 857 x 5280 = 4524960 ft/h
857 mi/h = 4524960 ft/h
Finally, we shall convert 4524960 ft/h to ft/min.
This can be obtained as follow:
Recall:
1 ft/h = 1/60 ft/min
Therefore,
4524960 ft/h = 4524960 x 1/60 = 75416 ft/min
4524960 ft/h = 75416 ft/min
Therefore, 857 mi/h is equivalent to 75416 ft/min.
To solve the above question in a shorter for we simply do the following:
(857 mi/h) x (5280 ft/h ÷ 1 mi/1h ) x (1h x 1 ft ÷ 60 min x 1 ft)
what is colloidal solutions
Explanation:
Colloidal solutions, or colloidal suspensions, are nothing but a mixture in which the substances are regularly suspended in a fluid. ... Colloidal systems can occur in any of the three key states of matter gas, liquid or solid. However, a colloidal solution usually refers to a liquid concoction.
Answer:
Colloidal solutions, or colloidal suspensions, are nothing but a mixture in which the substances are regularly suspended in a fluid.
a cylinder is filled with air its radius is 6.00 cm and its height is 3.50 cm what is the volume of air
Answer:
395.84cm^3
Explanation:
volume of a cylinder:
V=π(r^2)h
V = π((6cm)^2)(3.50cm) = 395.84cm^3
What is the difference between a volume that is delivered and a volume that is contained?
Answer:
When the graduation line denotes the volume contained in the calibrated vessel, the ware is marked “TC”. When the graduation line indicates the volume delivered from the vessel, the ware is marked “TD”.
The picture shows an element. Based on the information in the periodic table which element is shown in the picture? Carbon, Boron, lithium, helium! Please hurry guys
Answer:
Carbon
Explanation:
It has 6 protons... carbon has 6 protons
Draw the structural formula for ethynylcyclohexane.
Answer:
See attached picture.
Explanation:
Hello,
In this case, on the attached picture, you will find the required structure wherein we can see the ethynyl radical at the first carbon which is composed by two carbon atoms bonded via a triple bond due to the "ynyl" suffix. Moreover, the cyclohexane acts as the main chain.
Best.
Calculate the density of an object with a mass of 3.8 g, that when placed in a 10.0 mL graduated cylinder with an initial volume of 4.5 mL rises to a final volume of 8.6 mL. *
Answer : The density of an object is 0.93 g/mL
Explanation : Given,
Mass of an object = 3.8 g
Initial volume = 4.5 mL
Final volume = 8.6 mL
First we have to calculate the volume of an object.
Volume of an object = Final volume - Initial volume
Volume of an object = 8.6 mL - 4.5 mL
Volume of an object = 4.1 mL
Now we have to calculate the density of an object.
Formula used:
[tex]\text{Density}=\frac{\text{Mass of an object}}{\text{Volume of an object}}[/tex]
Now putting all the given values in this formula, we get:
[tex]\text{Density}=\frac{3.8g}{4.1mL}[/tex]
[tex]\text{Density}=0.93g/mL[/tex]
Therefore, the density of an object is 0.93 g/mL
Calculate the equilibrium constant for the reaction: 2 Cr + 3 Pb2+ ----> 3 Pb + 2 Cr3+ at 25oC. Eocell = 0.61 V
Answer:
The value is [tex]K = 8*10^{61}[/tex]
Explanation:
From the question we are told that
The equation is [tex]2 Cr + 3Pb^{2+} \to 3Pb + 2Cr^{3+}[/tex]
The temperature is [tex] T = 25^oC = 298 K [room \ temperature ][/tex]
The emf at standard condition is [tex]E^o_{cell} = 0.61 \ V[/tex]
Generally at the cathode
[tex]3Pb^{2+}(aq) + 6 e- --> 3Pb(s)[/tex]
At the anode
[tex]2Cr^{3+} + 6e^- \to 2Cr[/tex]
Generally for an electrochemical reaction, at room temperature the Gibbs free energy is mathematically represented as
[tex]G = n* F * E^o_{cell} [/tex]
Here n is the no of electron with value n = 6
F is the Faraday's constant with value 96487 J/V
=> [tex]G = 6 * 96487 * 0.61[/tex]
=> [tex]G = 3.5 *10^{5} \ J[/tex]
This Gibbs free energy can also be represented mathematically as
[tex]G = RTlogK[/tex]
Here R is the cell constant with value 8.314J/K
K is the equilibrium constant
From above
=> [tex]K = antilog^{\frac{G}{ RT} }[/tex]
Generally antilog = 2.718
=>[tex]K = 2.718^{\frac{3.5 *10^5}{ 8.314* 298} }[/tex]
=> [tex]K = 8*10^{61}[/tex]
An intramuscular medication is given at 20 mg/kg of body weight. If you give 560 mg of medication to a patient, what is the patient’s weight in pounds? (1 kg = 2.20 lbs)
Answer:
62 lb
Explanation:
Step 1: Given data
Dosage of the intramuscular medication: 20 mg/kg of body weight
Mass of the intramuscular medication: 560 mg
Step 2: Calculate the body weight of the patient
560 mg IM × (1 kg BW/20 mg IM) = 28 kg BW
Step 3: Convert the body weight of the patient to pounds
We will use the relationship 1 kg = 2.20 lb.
28 kg × (2.20 lb/1 kg) = 62 lb
Question 3 of 10
In order to test a hypothesis, a scientist needs to:
A. perform an experiment.
B. summarize previously recorded data.
c. have other scientists agree with the hypothesis.
D. develop an educated guess.
Answer:
A- Perform an experiment
Explanation:
7. Experimental value of acceleration due to gravity is found to be
9.842 m/s². The accepted value of acceleration due to gravity is
9.81 m/s2. What is the percent error in calculation?
a 0.326 %
b 0.316 %
C 0.981 %
d 0.613 %
Answer : The correct option is, (a) 0.326 %
Explanation :
To calculate the percentage error, we use the equation:
[tex]\%\text{ error}=\frac{|\text{ Experimental value - Accepted value}|}{\text{ Accepted value}}\times 100[/tex]
We are given:
Experimental value = 9.842 m/s²
Accepted value = 9.81 m/s²
Now put all the given values in above equation, we get:
[tex]\%\text{ error}=\frac{|9.842 m/s^2- 9.81m/s^2|}{9.81m/s^2}\times 100[/tex]
[tex]\%\text{ error}=0.326\%[/tex]
Therefore, the percent error in calculation is 0.326 %
g Given that 50.0 mL of 0.100 M magnesium bromide reacts with 13.9 mL of silver nitrate solution according to the unbalanced equation MgBr21aq2 AgNO31aq2 S AgBr1s2 Mg1NO3221aq2 (a) What is the molarity of the AgNO3 solution
Answer:
0.719M AgNO₃
Explanation:
The balanced chemical equation is:
MgBr₂ + 2AgNO₃ ⇄ 2AgBr + Mg(NO₃)₂
Where 1 mole of magnesium bromide reacts completely with 2 moles of AgNO₃
Molarity is the ratio between moles of solution and its volume in liters (The volume of the solution is 13.9mL = 0.0139L). That means all we need is to determine moles of silver nitrate. It is possible to know by using the chemical equation, thus:
Moles AgNO₃:
Moles of MgBr₂:
50.0mL = 0.050L * (0.100mol / L) = 0.00500 moles of MgBr₂.
As 2 moles of AgNO₃ reacts per mole of MgBr₂ and the reaction occurs completely, moles of silver nitrate are:
0.00500 moles MgBr₂ * (2 moles AgNO₃ / 1 mole MgBr₂) =
0.0100 moles of AgNO₃ are in the solution.
And molarity is:
0.0100 moles AgNO₃ / 0.0139L =
0.719M AgNO₃Spongebob was trying to make Krabby Patties that weighed 12oz. He made 4 Krabby Patties. They all had the following weights: 12.12oz; 11.9oz; 12.2oz; 12.1oz. Is this an example of Accuracy? Precision? Both? Neither?
Answer:
Both accuracy and precision
Explanation:
This displays accuracy because the weights were all very close to 12 oz, which was the desired weight/true value. The weights only varied from 12 oz by 0.1 or 0.2 ounces.
Additionally, this displays precision because the weights were very close to each other as well. The weights only varied slightly, by 0.1 to 0.3 ounces
answer:
Both accuracy and precision
Explanation:
This displays accuracy because the weights were all very close to 12 oz, which was the desired weight/true value. The weights only varied from 12 oz by 0.1 or 0.2 ounces.
Additionally, this displays precision because the weights were very close to each other as well. The weights only varied slightly, by 0.1 to 0.3 ounces
Quinine C20H24N2O2, is a compound extracted from cinchona tree which is traditionally
used to treat malaria. If given a 1.08 g of quinine sample, calculate:
(a)the molecular mass of quinine.
(b)number of moles of quinine
Answer:
324.46 amu
3.33 × 10⁻³ mol
Explanation:
(a) Calculate the molecular mass of quinine, C₂₀H₂₄N₂O₂
We will add the mass of each atom times the number of each atom in a molecule.
20 × C + 24 × H + 2 × N + 2 × O
20 × 12.01 amu + 24 × 1.01 amu + 2 × 14.01 amu + 2 × 16.00 amu
324.46 amu
(b) Calculate the number of moles of quinine in 1.08 g of quinine
The molar mass of quinine is 324.46 g/mol.
1.08 g × (1 mol/324.46 g) = 3.33 × 10⁻³ mol
Which of the following molecules is diamagnetic according to molecular orbital theory? A) N₂⁺ B) N₂⁻ C) CN D) CN⁻
Answer:
D) CN⁻
Explanation:
Hund's Rule of Maximum Multiplicity state that electrons go into degenerate orbitals of sub-levels (p,d, and f ) singly before pairing commences. Hund's rule is useful in determining the number of unpaired electrons in an atom. As such, it explains some magnetic properties of elements.
An element whose atoms or molecules contain unpaired electrons is paramagnetic. i.e., weakly attracted to substances in a magnetic field.
On the other hand, the element whose atoms or molecules are filled up with paired electrons is known as diamagnetic, i.e., not attracted by magnetic substances.
According to the molecular orbital theory, the diamagnetic molecule is CN⁻ because of the absence of unpaired electrons.
CN⁻ is diamagnetic according to molecular orbital theory.
Hund's Rule of Maximum Multiplicity
Before partnering, electrons enter deficient orbitals of sub-levels individually.
The Hund's rule may be used to calculate the number of unattached electrons in an atom. As a result, various magnetic characteristics of elements are explained.
A paramagnetic substance has unpaired electrons in its atoms or molecules. In a magnetic field, they are slightly attracted to substances.
According to the molecular orbital theory
Because there are no unattached electrons, the diamagnetic compound is CN⁻.
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Calculate the mass of a substance with a density of 1.98 g/mL and a volume of 265 mL.
Answer:
mass = 524.7 gExplanation:
The density of a substance can be found by using the formula
[tex]Density = \frac{mass}{volume} [/tex]
Making mass the subject we have
mass = Density × volumeFrom the question
Density = 1.98 g/mL
volume = 265 mL
Substitute the values into the above formula and solve for the mass
That's
mass = 1.98 × 265
We have the final answer as
mass = 524.7 gHope this helps you
is ethyl ether a polar molecule
Answer:
Ethyl ethers are Non-polar solvent and can extract polar molecules such as fatty acids
A cup of gold colored metal bed was measured to have a mask for 25 g. By water displacement, the volume of the bed was calculated to be 40.0 mL. Given the following densities, identify the metal. Gold equals 19.3 g/milliliters copper equals 8.86 g/milliliters bronze equals 9.87 g/milliliters
Answer : The metal is copper.
Explanation :
As we are given that:
Mass of metal = 25 g
Volume of metal = 40.0 mL
Formula used:
[tex]\text{Density of metal}=\frac{\text{Mass of metal}}{\text{Volume of metal}}[/tex]
Now putting all the given values in this formula, we get:
[tex]\text{Density of metal}=\frac{25g}{40.0mL}[/tex]
[tex]\text{Density of metal}=8.86g/mL[/tex]
From this we conclude that the metal is copper whose density is 8.86 g/mL.
Hence, the metal is copper.
Write an equation to show how perchloric acid, HClO4, reacts with water. Include states of matter in your answer. Click in the answer box to open the symbol palette.
Answer:
HClO4(aq) + H2O(l) ⇄ H3O+(aq) + ClO4-(aq)
Explanation:
When an acid dissolves in water, it will produce hydronium ion, H3O+ as the only positive ion.
perchloric acid, HClO4, being an acid will react with water, H2O to produce hydronium ion, H3O+ as shown below:
HClO4(aq) + H2O(l) ⇄ H3O+(aq) + ClO4-(aq)
(3.434)(1.245)\43.234
Answer:
0.09889
Explanation:
Order of Operations: BPEMDAS
Sig figs: 4
Step 1: Write out equation
[tex]\frac{3.434(1.245)}{43.234}[/tex]
Step 2: Multiply
[tex]\frac{4.27533}{43.234}[/tex]
Step 3: Divide
0.098888
Step 4: Round
0.09889
An object has a mass of 5.52 g and a volume of 12 mL. What is the density of the object?
Answer:
Density = 0.46 g/mLExplanation:
Density of a substance can be found by using the formula
[tex]Density = \frac{mass}{volume} [/tex]From the question
mass = 5.52 g
volume = 12 mL
Substitute the values into the above formula and solve for the Density
That's
[tex]Density = \frac{5.52}{12} [/tex]We have the final answer as
Density = 0.46 g/mLHope this helps you
Answer:
Density is 0.46 g/mL
Explanation: