Answer:
The correct answer is - C) 3 hours.
Explanation:
Given:
The half-life = 1 hour
Solution:
The half-life of an element is the time required to decay half of its initial amount.
To complete 87.5%, there total numbers of half-live would be -
1st halflife = 50% of the initial amount
2nd half-life = 50 + 50% of (50) = 50 +25 = 75% of initial amount
3rd half-life = 50 + 50 % of (50) + 50% of (25) = 87.5% of initial amount
so, to complete the 87.5 % of decay it required 3 half lives, and each half-life take one hour thus, total time taken = 3 hours
An industrial process of producing ammonia gas runs with a 74.0% yield. How many kilograms of ammonia gas will be produced in this process if theoretically 50.1 Kg can be made
Answer:
37.1 kilograms of ammonia gas will be produced in this process
Explanation:
The percentage yield of the reaction is given by:
[tex](Yield)\%=\frac{\text{Experimental yield}}{\text{Theoretical yield}}\times 100[/tex]
According to question
The percentage yield of the given industrial process = 74.0%
The given theoretical yield of ammonia gas = 50.1 kg
The experimental yield of ammonia gas = x
The percentage yield of the reaction is calculated a:
[tex]74.0\%=\frac{x}{50.1 kg}\times 100[/tex]
Solving for x, we get:
[tex]x = 37.074 kg\approx 37.1 kg[/tex]
37.1 kilograms of ammonia gas will be produced in this process
Which of the following statements about the pH of 0.010 M HClO4 is correct?
pH=2.00, because [H+]=1.0×10−2M.
A: p H equals 2.00 , because the molar concentration of H with a positive 1 charge equals 1.0 times 10 to the negative 2 power molar .
pH=2.00, because [H+]=2.0×10−2M.
B: p H equals 2.00 , because the molar concentration of H with a positive 1 charge equals 1.0 times 10 to the negative 2 power molar .
pH>2.00, because HClO4 is a strong acid.
C: p H is greater than 2.00 , because H C l O 4 is a strong acid.
pH<2.00, because HClO4 is a weak acid.
Answer:
Option B: p H equals 2.00 , because the molar concentration of H with a positive 1 charge equals 1.0 times 10 to the negative 2 power molar .
pH = 2 because [H⁺] = 1×10¯² M
Explanation:
To know which option is correct, we shall determine the pH of the 0.010 M HClO₄ solution. This can be obtained as follow:
We'll begin by calculating the concentration of the hydrogen ion [H⁺] in the solution. This is illustrated below:
HClO₄ is a strong acid and will dessociates as follow:
HClO₄ (aq) —> H⁺ (aq) + ClO₄¯ (aq)
From the balanced equation above,
1 mole of HClO₄ produced 1 mole H⁺.
Therefore, 0.010 M HClO₄ will also produce 0.010 M H⁺.
Finally we shall determine the pH of the solution. This can be obtained as follow:
Concentration of the hydrogen ion [H⁺] = 0.010 = 1×10¯² M
pH =?
pH = –Log [H⁺]
pH = –Log 1×10¯²
pH = 2
Thus,
The pH = 2
because,
[H⁺] = 1×10¯² M
Thus, option B gives the correct answer to the question.
Based on the definition of pH, pH of 0.010 M solution of HClO4 equals 2.00, because the molar concentration of H with a positive 1 charge equals 1.0 times 10 to the negative 2 power molar.
What is pH?The pH of a solution is the negative logarithm of the hydrogen ion concentration of a solution.
pH of a solution is a measure of the acidity of the solution.
pH = - log[H+]where
[H+] is hydrogen ion concentrationFor the 0.010 M solution of HClO4, [H+} = 0.01 M
pH = -log(0.01)
pH = 2.00
Therefore, pH of 0.010 M solution of HClO4 equals 2.00, because the molar concentration of H with a positive 1 charge equals 1.0 times 10 to the negative 2 power molar.
Learn more about pH at: https://brainly.com/question/172153
What is the present Ba in Ba(NO3)2?
Answer:
Percentage of Ba = 52.5%
Explanation:
We'll begin by calculating the molar mass of Ba(NO3)₂. This can be obtained as follow:
Molar mass of Ba(NO3)₂ = 137 + 2[14 +(16×3)]
= 137 + 2[14 + 48]
= 137 + 2[62]
= 137 + 124
= 261 g/mol
Next, we shall determine the mass of Ba in Ba(NO3)₂. This can be obtained as follow:
Mass of Ba in Ba(NO3)₂ = 137 g/mol
Finally, we shall determine the percentage of Ba in Ba(NO3)₂. This can be obtained as follow:
Percentage of Ba = mass of Ba / mass of Ba(NO3)₂ × 100
Percentage of Ba = 137 / 261 × 100
Percentage of Ba = 13700 / 261
Percentage of Ba = 52.5%
Thus, the percentage of Ba in Ba(NO3)₂ is 52.5%
In the reaction below does water acts as the acid or as the base?
H2S + H20 - HS1- + H30+ *
O a. Neither, water is neutral
O b. Acid
O C. Base
Answer:
C. Base.
Explanation:
Hello there!
In this case, according to the given information, it turns out convenient for us to realize that the concept acid and base we should use here is based off the Bronsted-Lowry one, which says that an acid is a hydrogen donor. In such a way, since water accepts one H ion as it goes to H3O⁺, we infer it is C. Base and the H2S the acid.
Also, we can tell HS⁻ is the conjugate base and H3O⁺ the conjugate acid.
Regards!
I
Gggggggggggggsgstststsysgtetwtwtst
Answer:
ummm u ok?
Explanation:
Calculate the molarity of a potassium hydroxide solution if 25.0 mL of this solution was completely neutralized by 23.3 mL of 0.506 M sulfuric acid.
Show your work.
In this image, which fundamental interaction is responsible for attracting the electron?
a. electromagnetism
b. nuclear weak force
c. gravitation
d. nuclear strong force
Answer:
a.
Explanation:
electromagnetism
Which of the following has the greatest mass for one mole of the compound?
A. SIHA
B. CO
C. CH3OH
D. C2H6
The concept molar mass is used here to determine the compound which has the greatest mass for its one mole. The correct option is C.
What is molar mass?The molar mass also defined as the molecular weight of a compound is generally the sum of the atomic masses of each atoms present in the given compound. Its unit is g mol⁻¹.
The mass of 1 mole of any substance is also called the molar mass. Evidently molar mass is equal to the atomic mass or the molecular mass denoted in grams depending upon whether the substance contains atoms or molecules.
Here (SiHA) is known as the most important bioceramic which is used in the field of bioactive bone implants. The compound CO is carbon monoxide, CH₃OH is methanol and C₂H₆ is ethane.
The molar mass of the given compounds are obtained by adding their atomic masses :
CO = (12.011 g/mol+ 15.999 g/mol) = 28.01 g/mol
CH₃OH = (12.011 g/mol + 3 × 1.007 g/mol + 15.999 g/mol + 1.007 g/mol) = 32.04 g/mol
C₂H₆ = (2 × 12.011 g/mol + 6 × 1.007 g/mol) = 30.07 g/mol
Here among the given compounds CH₃OH has the greatest mass for one mole of the compound.
Thus the correct option is C - CH₃OH.
To know more about the molar mass, visit;
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Hypothetical element A has three stable isotopes. The first isotope has a mass of 35.01 amu and an abundance of 35.00%. The second isotope has a mass of 36.01 amu and an abundance of 15.00%. The third isotope has a mass of 37.02 amu and an abundance of 50.00%. What is the atomic mass of element A
Answer:
36.16 amu
Explanation:
From the question given above, the following data were obtained:
1st Isotope:
Mass of 1st isotope = 35.01 amu
Abundance of 1st isotope = 35%
2nd isotope:
Mass of 2nd isotope = 36.01 amu
Abundance of 2nd isotope = 15%
3rd isotope:
Mass of 3rd isotope = 37.02 amu
Abundance of 3rd isotope = 50%
Atomic mass of element A =?
The atomic mass of element A can be obtained as follow:
Atomic mass = [(mass of 1st × Abundance)/100] + [(mass of 2nd × Abundance)/100] + [(mass of 3rd × Abundance)/100]
= [(35.01 × 35)/100] + [(36.01 × 15)/100] + [(37.02 × 50)/100]
= 12.25 + 5.40 + 18.51
= 36.16 amu
Thus, the atomic mass of element A is 36.16 amu
What is a metal oxide + acid
Metal oxide + acid —> __+__
Answer:
Metal oxide + acid —> salt + water
Explanation:
Help!!
There are 9.23 x 1023 molecules of water in a beaker, how many moles are there?
Answer: There are 1.53 moles present in [tex]9.23 \times 10^{23}[/tex] molecules of water in a beaker.
Explanation:
According to the mole concept, there are [tex]6.022 \times 10^{23}[/tex] molecules present in 1 mole of a substance.
So, number of moles present in [tex]9.23 \times 10^{23}[/tex] molecules are calculated as follows.
[tex]Moles = \frac{9.23 \times 10^{23}}{6.022 \times 10^{23}}\\= 1.53 moles[/tex]
Thus, we can conclude that there are 1.53 moles present in [tex]9.23 \times 10^{23}[/tex] molecules of water in a beaker.
help ASAP will give brainlist
Answer:
1. 3.83 L
2. 0.368 mole
Explanation:
1. Determination of the volume
Pressure (P) = 3.21 atm
Temperature (T) = 202 K
Number of mole (n) = 0.741 mole
Gas constant (R) = 0.0821 L.atm/molK
Volume (V) =?
The volume can be obtained by using the ideal gas equation as illustrated below:
PV = nRT
3.21 × V = 0.741 × 0.0821 × 202
3.21 × V = 12.3497283
Divide both side by 3.21
V = 12.2888922 / 3.21
V = 3.83 L
Thus, the volume of the gas is 3.83 L
2. Determination of the number of mole.
Pressure (P) = 2.50 atm
Temperature (T) = 215 K
Volume (V) = 2.60 L
Gas constant (R) = 0.0821 L.atm/molK
Number of mole (n) =?
The number of mole can be obtained by using the ideal gas equation as illustrated below:
PV = nRT
2.50 × 2.60 = n × 0.0821 × 215
6.5 = n × 17.6515
Divide both side by 17.6515
n = 6.5 / 17.6515
n = 0.368 mole
Thus, the number of mole of the gas is 0.368 mole.
HEEELP! What are some examples of nuclear fusion? Select all the correct answers.
A: Being the power source of stars
B: Forming heavier elements from light elements
C: Generating electricity in power plants
D: Being used in thermonuclear weapons
E: Supplying the power source in nuclear submarines
Answer:
A B D
Explanation:
Answer: A: Being the power source of stars
B: Forming heavier elements from light elements
D: Being used in thermonuclear weapons
Explanation: (Edmentum)
8. An ion with 5 protons, 6 neutrons, and a charge of 3+ has an
atomic number of
a) 5
b) 6
c) 8
d) 11
Atomic number = The number of proton in an atom or ion so the right answer is 5!
A 0.457-M aqueous solution of (CH3)2NH (dimethylamine) has a pH of 12.2. Calculate the pH of a buffer solution that is 0.457 M in (CH3)2NH and 0.280 M in (CH3)2NH2 .
Answer:
pH = 10.95
Explanation:
To solve this question we must, as first, find pKb of dimethylamine. Then, using H-H equation we can solve the pH of the buffer:
pKb dimethylamine:
Based on the equilibrium:
(CH3)2NH(aq) + H2O(l) ⇄ (CH3)2NH2⁺(aq) + OH-(aq)
Kb is defined as:
Kb = [OH-] [(CH3)2NH2⁺] / [(CH3)2NH]
Both (CH3)2NH2⁺(aq) + OH- comes from the same equilibrium, that means:
[OH-] = [(CH3)2NH2⁺]
And: [(CH3)2NH] = 0.457M
[OH-] can be obtained from pH as follows:
14 -pH = pOH
14-12.2 = 1.8 =pOH
10^-pOH = [OH-] = 0.01585M
Replacing:
Kb = [0.01585M] [(0.01585M] / [0.457M]
Kb = 5.50x10⁻⁴
pKb = -logkb = 3.26
pH of the buffer:
Using H-H equation for bases:
pOH = pKb + log [conjugate acid] / [weak base]
pOH = 3.26 + log [0.280M] / [0.457M]
pOH = 3.05
pH = 14 - pOH
pH = 10.95A 2.00 L flask is filled with propane gas (C3H8) at a pressure of 1.10 atm and a temperature of 258 K. What is the mass of propane in the flask?
Answer:
m = 4.58 g.
Explanation:
Hello there!
In this case, according to the given information, it turns out possible for us to realize this problem is solved via the ideal gas equation:
[tex]PV=nRT[/tex]
As we can calculate the moles of propane given the pressure, temperature and volume as shown below:
[tex]n=\frac{PV}{RT} \\\\n=\frac{1.10atm*2.00L}{0.08206\frac{atm*L}{mol*K}*258K} \\\\n=0.104mol[/tex]
Finally, since the molar mass of propane is 44.1 g/mol, we calculate the mass by following the shown below mole-mass conversion factor:
[tex]m=0.104mol*\frac{44.1g}{1mol}\\\\m= 4.58g[/tex]
Regards!
Quais são os nomes dos planetas anões
Answer:
Can you translate it on English so we can understand
When the pressure and number of particles of a gas are constant, which of the following is also constant
PLEASE HELP AND DO NOT SEND A LINK IF YOU DO YOU WILL BE REPORTED
I need help with this I don't know if I'm getting this right please help and give explanations as well and if you don't know both of the question please answer one
1.Three glasses A, B, C contain the liquids: deionized water in A, sulfuric acid solution in B and sodium hydroxide solution in C. Arrange the liquids of the three glasses in order of increasing pH
2.What values can the pH of a base solution at 25 o C take?
Use the average volume of HNO3 used to calculate the concentration of
NaOH ?
Answer:
Incomplete question. You didn't give the volume of HNO3
A sample of 240.0 K and 670 mm Hg occupies a 128 mL volume bottle. What volume will the gas occupy at -75 degrees celsius (If the pressure remains constant)?
Answer:
New volume = 105.6 mL
Explanation:
Given that,
Temperature, T = 240.0 K
Pressure, P = 670 mm Hg
Volume, V = 128 mL
New temperature = -75°C = 198 K
We need to find the new volume. Let it is V'. The relation between volume and the temperature is given by :
[tex]V=kT\\\\\dfrac{V}{V'}=\dfrac{T}{T'}\\\\V'=\dfrac{VT'}{T}\\\\V'=\dfrac{128\times 198}{240}\\\\V'=105.6\ mL[/tex]
So, the new volume is equal to 105.6 mL.
Helpppp pleaseee ill give brainliest
Answer:
The answers are in the explanation.
Explanation:
The energy required to convert 10g of ice at -10°C to water vapor at 120°C is obtained per stages as follows:
Increasing temperature of ice from -10°C - 0°C:
Q = S*ΔT*m
Q is energy, S specific heat of ice = 2.06J/g°C, ΔT is change in temperature = 0°C - -10°C = 10°C and m is mass of ice = 10g
Q = 2.06J/g°C*10°C*10g
Q = 206J
Change from solid to liquid:
The heat of fusion of water is 333.55J/g. That means 1g of ice requires 333.55J to be converted in liquid. 10g requires:
Q = 333.55J/g*10g
Q = 3335.5J
Increasing temperature of liquid water from 0°C - 100°C:
Q = S*ΔT*m
Q is energy, S specific heat of ice = 4.18J/g°C, ΔT is change in temperature = 100°C - 0°C = 100°C and m is mass of water = 10g
Q = 4.18J/g°C*100°C*10g
Q = 4180J
Change from liquid to gas:
The heat of vaporization of water is 2260J/g. That means 1g of liquid water requires 2260J to be converted in gas. 10g requires:
Q = 2260J/g*10g
Q = 22600J
Increasing temperature of gas water from 100°C - 120°C:
Q = S*ΔT*m
Q is energy, S specific heat of gaseous water = 1.87J/g°C, ΔT is change in temperature = 20°C and m is mass of water = 10g
Q = 1.87J/g°C*20°C*10g
Q = 374J
Total Energy:
206J + 3335.5 J + 4180J + 22600J + 374J =
30695.5J =
30.7kJ
hetrocyclic reactions
Answer:
I am really sorry but i really don't no
If 5.0 liters of hydrogen react with excess oxygen, what mass of water would be produced?
Answer:
our equation specifies that
32
⋅
g
of dioxygen and
4
⋅
g
of dihydrogen give
36
⋅
g
of water upon reaction, so..........
Explanation:
2
H
2
(
g
)
+
O
2
(
g
)
→
2
H
2
O
(
g
)
We started with
5.0
⋅
g
32.00
⋅
g
⋅
m
o
l
−
1
=
0.156
⋅
m
o
l
dioxygen
.
Given excess dihydrogen, this molar quantity thus gives
2
×
0.156
⋅
m
o
l
water.
And thus,
2
×
0.156
⋅
m
o
l
×
18.01
⋅
g
⋅
m
o
l
−
1
≅
6
⋅
g
water are evolved. Is this reaction exothermic or endothermic?
Which of these is NOT a physical change? *
Cooking an egg.
O Evaporation of water.
Magnetisation of iron.
O Ripping a piece of paper in half.
PLS HELP
Answer:
magnetism of water
Explanation:
Not sure
The gases in a hair spray can are at a temperature of 26.0 °C and a pressure of 25.0 lbs/in2. If the gases in the can reach a pressure of
90.0 Ibs/in?, the can will explode. To what temperature in Celsius must the gases be raised in order for the can to explode?
Answer:
The gases in a hair spray can are at a temperature of 26.0 °C and a pressure of 25.0 lbs/in2.
If the pressure becomes [tex]90.0lbs/in^{2}[/tex], what is the temperature of the gases?
Explanation:
According to Gay lussac's law:
the pressure of a gas is directly proportional to its absolute temperature.
[tex]P\alpha T[/tex]
[tex]\frac{P{1} }{T{1} }=\frac{P{2} }{T{2} }[/tex]
Given,
[tex]P1=25.0lbs/in^{2} \\P2=90.0lbs/in^{2} \\T1=26^{o} C=(26+273)K=299K\\T2=?[/tex]
Substitute these values in the above formula:
[tex]\frac{P{1} }{T{1} }=\frac{P{2} }{T{2} }\\\\\frac{25lbs/in^{2} }{299K} }=\frac{90.0lbs/in^{2} }{T{2} }\\\\\\On simplification \\T2=1076.4K\\T2=(1076.4-273)^{o} C=803.4^{o} C[/tex]
Answer:
The gases will be raised to a temperature of 803.4[tex]^{o} C[/tex].
what is the definition of isomerism
Answer:
Isomerism is the phenomenon in which more than one compounds have the same chemical formula but different chemical structures. Chemical compounds that have identical chemical formulae but differ in properties and the arrangement of atoms in the molecule are called isomers. Therefore, the compounds that exhibit isomerism are known as isomers.
The word “isomer” is derived from the Greek words “isos” and “meros”, which mean “equal parts”. This term was coined by the Swedish chemist Jacob Berzelius in the year 1830.
Explanation:
What is the molar mass of 4.23 g of an elemental gas in a 2.5L container at 282K and 1.4 atm?
Answer:
27.98g/mol
Explanation:
Using ideal gas law equation;
PV = nRT
Where;
P = pressure (atm)
V = volume (L)
T = temperature (K)
n = number of moles (mol)
R = gas law constant (0.0821 Latm/molK)
According to the information given:
V = 2.5L
P = 1.4 atm
T = 282K
n = ?
Using PV = nRT
n = PV/RT
n = 1.4 × 2.5/0.0821 × 282
n = 3.5/23.1522
n = 0.151mol
Using the formula to calculate molar mass of the elemental gas:
mole = mass/molar mass
Molar mass = mass/mole
Molar mass = 4.23g ÷ 0.151mol
Molar mass = 27.98g/mol
g a 144 g metal bar requires 2500 J to change its temperature from 23.5 to 100 degree C what is the specific heat of the metal
Answer:
226.9 J·kg⁻¹·°C⁻¹
Explanation:
The specific heat of a substance can be defined as the amount is heat that has to be added in order for a given mass of the substance to increase its temperature:
c = ΔQ/(m*ΔT)In this case:
ΔQ = 2500 Jm = 144 g ⇒ 144 g / 1000 = 0.144 kgΔT = 100 - 23.5 = 76.5 °CWe input the data:
c = 2500 J / (0.144 kg * 76.5 °C)And calculate c:
c = 226.9 J·kg⁻¹·°C⁻¹Claims · Evidence • Reasoning A student
claims that any change in matter can be
classified as either a physical change or a
chemical change. Do you agree or disagree?
What evidence would you use to support your
claim? Explain your reasoning.