9. What are the advantages of using an indicator to inform pH measurements? What are the advantages of using a pH meter?
Answer:
The advantages of using an indicator to inform pH measurements:
It gives a mathematically result of the pH, in addition, it gives the precise pH of solvent, and it also gives an idea of the straight of the solution also.
Now, the advantage of using a pH meter:
It is a rapid method to characterize between acids, bases. However, this method does not show how strong acid or base actually are, plus it tends to gives a range of acidity or basicity not quite accurate as a result.
Ammonia, NH3 is a common base with Kb of 1.8 X 10-5. For a solution of 0.150 M NH3:
Write the equation for the ionization of ammonia in water.
List all species present in the solution AND determine the concentrations of each.
Determine the pH of this solution.
The concentrations : 0.15 M
pH=11.21
Further explanationThe ionization of ammonia in water :
NH₃+H₂O⇒NH₄OH
NH₃+H₂O⇒NH₄⁺ + OH⁻
The concentrations of all species present in the solution = 0.15 M
Kb=1.8 x 10⁻⁵
M=0.15
[tex]\tt [OH^-]=\sqrt{Kb.M}\\\\(OH^-]=\sqrt{1.8\times 10^{-5}\times 0.15}\\\\(OH^-]=\sqrt{2.7\times 10^{-6}}=1.64\times 10^{-3}[/tex]
[tex]\tt pOH=-log[OH^-]\\\\pOH=3-log~1.64=2.79\\\\pH=14-2.79=11.21[/tex]
Consider the balanced equation.
CuSO4 + Zn Right arrow. ZnSO4 + Cu
If 200.0 g of copper(II) sulfate react with an excess of zinc metal, what is the theoretical yield of copper?
1.253 g
50.72 g
79.63 g
194.3 g
Answer:
79.63
Explanation:
what is a stethoscope
Explanation:
A stethoscope is used to listen to sounds that the heart , lungs , blood flow , intestines make.
A. The chemical formula for iron (III) sulfate is Fe2(SO4)3. How many atoms of each element are present?
2 iron, 3 sulfur, 12 oxygen
3 iron, 3 sulfur, 12 oxygen
2 iron, 1 sulfur, 4 oxygen
6 iron, 3 sulfur, 12 oxygen
B.How many moles of hydrogen are in 1.8 mole(s) of quinine?
Express your answer using two significant figures.
C. How many moles of carbon are in 5.4 moles of quinine?
Express your answer using two significant figures.
D. How many moles of nitrogen are in 2.0×10−2 mole of quinine?
Express your answer using two significant figures.
Answer:
A. 2 Fe, 3 S and 12 O
B. 43 moles of H
C. 1.0×10² moles of C
Explanation:
A. Formula for iron (III) sulfate is Fe₂(SO₄)₃
This salt has 2 atoms of iron and 3 sulfates, so in total we have:
2 Fe, 3 S and 12 O
Pay attention to the subscripts
B. Formula for quinine is: C₂₀H₂₄N₂O₂
If we continue with the example before we can say that 1 mol of Iron (III) sulfate contains 2 moles of Fe, 3 moles of S and 12 moles of O
Then, 1 mol of quinine contains 24 moles of H
So 1.8 moles of quinine, may contain (1.8 . 24) /1 = 43 moles of H
C. 1 mol of quinine contains 20 moles of C
5.4 moles of quinine may contain (5.4 . 20) /1 = 1.0×10²
(As the answer must be in 2 significant figures and the real answer is 108, I had to use scientific notation)
1.
10
2.
3.
4.
60
Which polygons are similar?
110
60
10
01
02
03
04
Answer:
The answer is "1 and 4 polygons were similar".
Explanation:
In the given question, in both figures 1 and 4, it's measure angle were 10, 60, 110. In figure number 4, its angle is 10, 60, and on the third side, its value is equal to 110, which is (180 - 70).
compare the size of I, I+ and I-
umm explanation pls so i answee
Chlorine (Cl) is 76% chlorine-35 and 24% chlorine-37. Determine the average atomic mass of chlorine. Show/Explain work.
Answer:
Average atomic mass of chlorine is 35.48 amu.
Explanation:
Given data:
Percent abundance of Cl-35 = 76%
Percent abundance of Cl-37 = 24%
Average atomic mass = ?
Solution:
Average atomic mass = (abundance of 1st isotope × its atomic mass) +(abundance of 2nd isotope × its atomic mass) / 100
Average atomic mass = (76×35)+(24×37) /100
Average atomic mass = 2660 + 888 / 100
Average atomic mass = 3548/ 100
Average atomic mass = 35.48 amu
Average atomic mass of chlorine is 35.48 amu.
Can someone please help me quick !!!
a certain quantity of gas occupies 20l at 50°c and pressure of 2 atm.at what pressure will the volume of the gas will be occupy 2L,if the temperature does not change?
Answer:
20atm
Explanation:
according to boyles law P1V1= P2V2
What happens to the gravitational potential energy of an object if you bring it higher with respect to the ground? *
Answer:
Increases
Explanation:
The gravitational potential energy of an object increases as you bring it higher with respect to the ground.
Gravitational potential energy depends on the mass, height and gravity between two bodies;
Gravitational potential energy = mgh
m is the mass
g is the height
h is the height
We can clearly see that the higher the elevation, the more the value of the gravitational potential energy.A sample of compound contains 5.65x10 21 molecules molar mass of the compound is 89.06g/ mol determine the mass of the sample in grams
Answer:
Explanation:
no of molecules=5.65*10^21
NA=6.23*10^23
no of moles=no of molecules/avogadro number
no of moles=5.65*10^21/6.23*10^23
no of moles=9.07*10^-3
now we know that
no of moles=mass/molar mass
mass=no of moles*molar mass
mass=9.07*10^-3*89.06
mass=0.808 g
PLS HURRY
What methods are you using to test this (or each) hypothesis?
Answer:
Fair test.
PLS GIVE BRAINLIEST
The volume of a sample of hydrogen gas was decreased from 11.95 L to 5.24 L at constant temperature. If the final pressure exerted by the hydrogen gas sample was 9.31 atm, what pressure did the hydrogen gas exert before its volume was decreased?
Answer:
P1 = 21.23 atm
Explanation:
Initial Volume V1 = 11.95 L
Final Volume V2 = 5.24L
Final Pressure P2 = 9.31 atm
Initial Pressure P1 = x
The relationship between these values is given as;
P1 / V1 = P2 / V2
P1 / 11.95 = 9.31 / 5.24
P1 = 21.23 atm
The atomic number of beryllium (Be) is 4, and the atomic number of barium (Ba) is 56. Which comparison is best supported by this information?
a. They are in the same group because they have similar atomic masses, but they are in different periods because they have different chemical properties.
b. They are in the same group because they have similar chemical properties, but they are in different periods because they have very different atomic numbers.
c. They are in the same group because their atomic numbers are each multiples of four, but they are in different periods because they have different chemical properties.
d. They are in the same group because they have similar atomic masses, but they are in different periods because they have very different atomic numbers.
Answer:
B: They are in the same group because they have similar chemical properties, but they are in different periods because they have very different atomic numbers.
Explanation:
I took the Unit test on EDG and I got it correct
Pls mark me brainliest
Which of the following elements can only form single covalent bonds when forming molecular compounds?
a) Nitrogen
b) Hydrogen
c) Carbon
d) Oxygen
Hydrogen can only form single covalent bonds when forming molecular compounds. Therefore, option B is correct.
What is covalent bond?A covalent bond is a type of chemical bond formed between two or more atoms in which electrons are shared between them. Covalent bonds usually occur between nonmetal atoms and are formed by the sharing of valence electrons.
Hydrogen can only form a single covalent bond because it has only one valence electron and needs one more electron to complete its valence shell, making it stable.
Nitrogen can form triple covalent bonds, carbon can form multiple covalent bonds, and oxygen can form double covalent bonds in molecular compounds.
Thus, option B is correct.
To learn more about the covalent bond, follow the link:
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Graphite is sometimes used to reduce the friction between
two surfaces that are rubbing together.
Explain how it does this.
Graphite is sometimes used to reduce the friction between two surfaces that are rubbing together. Therefore, this happen because of weak covalent bond.
What is graphite?Graphite is among the most prevalent carbon allotropes. It is also the stable allotrope for carbon, and as such, it is employed in electrochemistry to define the heat of synthesis of carbon compounds. With a hardness of 2.09-2.23 g/cm3, graphite is an excellent conductor of electricity and heat.
Graphite is a large covalent structure in which each carbon atom is covalently linked to three other carbon atoms. Graphite is sometimes used to reduce the friction between two surfaces that are rubbing together. This happen because of weak covalent bond.
Therefore, graphite is sometimes used to reduce the friction between two surfaces that are rubbing together. This happen because of weak covalent bond.
To know more about graphite, here:
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Why is Mg++ smaller than Mg atom?
Answer:
The magnesium ion is much smaller than the magnesium atom because magnesium atom contains more electrons as compared to magnesium ion. Explanation: ... Whereas when an atom tends to lose an electron then it acquires a positive charge and size of the atom tends to increase.
Answer:
Because it looses it two electrons to form a stable octet Ionic form..........
how many elements are present No and NO
The internal energy of reaction is -855.1). The reaction has a change of
temperature of 63.20°C that consist of 8.85g of material. Assume the
heat capacity of 2.650J/g °C. What is the work energy of this process..
The work energy of this process : 2337.298 J
Further explanationThe laws of thermodynamics 1 state that: energy can be changed but cannot be destroyed or created
ΔU=Q-W
Q=m.c.Δt
[tex]\tt Q=8.85\times 2.650\times 63.2=1482.198~J[/tex]
the work (W) :
[tex]\tt W=Q-\Delta U\\\\W=1482.198-(-855.1)=2337.298~J[/tex]
(Question) : What is the specific gravity of liquid sample with a mass
of 35.0 g and a volume of. 14.00 mL ?
Answer:
48.0g is the specific gravity of liquid sample with a mass of 35.0g and a volume of 14.00 mL
what mass of potassium chlorate should be required to produce 113 L of oxygen O2. measured at STP g
Answer:
411.6 g
Explanation:
The equation for the decomposition of potassium chlorate to produce oxygen is given as;
2KClO3 --> 2KCl + 3O2
From the stochiometry of the reaction 2 mole of KClO3 produces 3 mol of O2
At STP,
1 mol = 22.4L
3 mol = x
x = 67.2L
2 mole of KClO3 produces 67.2L of O2
How many moles would produce 113L?
2 = 67.2
x = 113
x = 3.36 moles
Moles can be converted to mass using;
Mass = moles * Molar mass
Mass = 3,36 * 122.5 g/mol
Mass = 411.6 g
Be sure to answer all parts. How many moles of O are needed to combine with 0.276 mole of C to form CO
Answer:
0.138 moles of oxygen are needed to combine with 0.276 moles of carbon.
Explanation:
Given data:
Moles of oxygen needed = ?
Moles of carbon present = 0.276 mol
Solution:
Chemical equation:
2C + O₂ → 2CO
Now we will compare the moles of carbon with oxygen.
C : O₂
2 : 1
0.276 : 1/2×0.276 = 0.138 mol
Thus, 0.138 moles of oxygen are needed to combine with 0.276 moles of carbon.
HELLPPPPP!
Each employee should be responsible for keeping his or her work station clean throughout the work shift.
True
False
Answer:
true
Explanation:
How many atm is 25.0 psi?
Answer:
1.70115 or 1.70 atm
Explanation:
1 psi is equal to 0.068046 atm.
Rank the following chemical species from largest ionic radius to smallest ionic radius
V^3+, V^5+, V^4+, V^2+
Answer:
Biggest Radii V²⁺ > V³⁺ > V⁴⁺ > V⁵⁺ Smallest Radii
General Formulas and Concepts:
Periodic Trends: Atomic/Ionic RadiiCoulomb's LawExplanation:
The Periodic Trend for Atomic Radii is down and to the left. Therefore, the element with the largest radius would be in the bottom left corner of the Periodic Table.
Anions will always have a bigger radii than the parent radii. When we add e⁻ to the element, we are increasing the e⁻/e⁻ repulsions. This will cause e⁻ to repel themselves more and thus create more space, increasing the radii size.
Cations will always have smaller radii than the parent radii. When we remove e⁻ from the element, we are decreasing e⁻/e⁻ repulsions. Since there are less e⁻, there is no need for more space and thus decreases the radii size.
Since Cations are smaller than the parent radii, the more e⁻ we remove, the smaller it will become.
Therefore, the least removed e⁻ Vanadium would be the largest and the most removed e⁻ Vanadium would be the smallest.
How many milliliters of 2.00 M H2SO4 will react with 28.0 g of NaOH?
Taking into account the reaction stoichiometry and the definition of molarity, 175 mL of 2 M H₂SO₄ will react with 28.0 g of NaOH.
Reaction stoichiometryIn first place, the balanced reaction is:
H₂SO₄ + 2 NaOH → Na₂SO₄ + 2 H₂O
By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:
H₂SO₄: 1 moleNaOH: 2 moles Na₂SO₄: 1 moleH₂O: 2 molesThe molar mass of the compounds is:
H₂SO₄: 98 g/moleNaOH: 40 g/moleNa₂SO₄: 142 g/moleH₂O: 18 g/moleThen, by reaction stoichiometry, the following mass quantities of each compound participate in the reaction:
H₂SO₄: 1 mole× 98 g/mole= 98 gramsNaOH: 2 moles× 40 g/mole= 80 gramsNa₂SO₄: 1 mole× 142 g/mole= 142 gramsH₂O: 2 moles× 18 g/mole= 36 gramsDefinition of molarityMolar concentration or molarity is a measure of the concentration of a solute in a solution and indicates the number of moles of solute that are dissolved in a given volume.
The molarity of a solution is calculated by dividing the moles of solute by the volume of the solution:
[tex]Molarity= \frac{number of moles}{volume}[/tex]
Molarity is expressed in units [tex]\frac{moles}{liter}[/tex].
Moles of H₂SO₄ requiredThe following rule of three can be applied: If by reaction stoichiometry 80 grams of NaOH react with 1 mole of H₂SO₄, 28 grams of NaOH react with how many moles of H₂SO₄?
[tex]moles of H_{2}S O_{4} =\frac{28 grams of NaOHx1 mole ofH_{2}S O_{4} }{80 grams of NaOH}[/tex]
moles of H₂SO₄= 0.35 moles
Volume of H₂SO₄ requiredIn this case, you know:
Molarity= 2 M= 2 [tex]\frac{moles}{liter}[/tex]amount of moles= 0.35 molesReplacing in the definition of molarity:
[tex]2 \frac{moles}{liter}= \frac{0.35 moles}{volume}[/tex]
Solving:
2 [tex]\frac{moles}{liter}[/tex] × volume= 0.35 moles
volume= 0.35 moles ÷ 2 [tex]\frac{moles}{liter}[/tex]
volume= 0.175 liters= 175 mL (being 1 L= 1000 mL)
Finally, 175 mL of 2 M H₂SO₄ will react with 28.0 g of NaOH.
Learn more about
the reaction stoichiometry:
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molarity:
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PLS HELP!!!
What does it mean when there is a physical change?
A new substance has been formed.
Matter has changed on the molecular level.
Matter has changed from one substance into another.
Matter has changed size, shape or form.
Answer:
Physical Change. Physical changes are changes in which no bonds are broken or formed. This means that the same types of compounds or elements that were there at the beginning of the change are there at the end of the change.
In a classroom, which comparison would a teacher most likely use for describing a mole?
a cup of water and a liter of oil
a dozen eggs and a dozen jellybeans
a jar of jellybeans and a gram of salt crystals
20 marbles in a bag and 10 large ice cubes
Answer:
B
Explanation:
a mole is "a chemist's dozen" lol
what is the source of the force that moves the tectonic plates along this plate boundary
Answer:
Mantle convection
Explanation:
The source of the force that moves tectonic plates along plate boundaries is as a result of the mantle convection.
Heat energy produced in the mantle especially from radioactive decay is a very important source of internal heat that drives plate motion. Denser and cold materials close to the over-riding lithosphere above sinks deep into the mantle. Hotter and lighter materials rises to the surface. This sets up a convection cell by which the plates above are driven.