Answer:
2.5 mol/L
Explanation:
We'll begin by calculating the number of mole in 7 g of KOH. This can be obtained as follow:
Mass of KOH = 7 g
Molar mass of KOH = 39 + 16 + 1
= 56 g/mol
Mole of KOH =?
Mole = mass /molar mass
Mole of KOH = 7 / 56
Mole of KOH = 0.125 mole
Next, we shall convert 50 mL to L. This can be obtained as follow:
1000 mL = 1 L
Therefore,
50 mL = 50 mL × 1 L / 1000 mL
50 mL = 0.05 L
Finally, we shall determine the molarity of the KOH solution. This can be obtained as follow:
Mole of KOH = 0.125 mole
Volume = 0.05 L
Molarity of KOH =?
Molarity = mole / Volume
Molarity of KOH = 0.125 / 0.05
Molarity of KOH = 2.5 mol/L
Thus, the molarity of the KOH solution is 2.5 mol/L
how does a heavy growth of algae decrease the concentration of oxygen in a lake?
Answer:
Explanation:
iuhyesfdxgrygtvd ctrfdrdt6r76_jjdvrud83447+je8867vbde turn left then go right back then stop done
Match each phylum with the correct description
cnidarians
internal skeletons made of hardened plates
echinoderms
radial symmetry and stinging cells
arthropods
jointed body parts and an external skeleton
annelids
segmented body and closed circulatory
system
Answer:
:) Here
Explanation:
2 attempts len
Check my work
The density of sucrose, table sugar, is 1.56 g/ec. What volume (in cubic centimeters) does 19.0 g of
sucrose occupy?
cc
Answer:
12.18 cc
Explanation:
From the question given above, the following data were obtained:
Density = 1.56 g/cc
Mass = 19 g
Volume =?
The density of a substance can be defined as the mass per unit volume of the substance. Mathematically, it can be expressed as:
Density = mass / volume
With the above formula, we can obtain the volume of the sucrose as follow:
Density = 1.56 g/cc
Mass = 19 g
Volume =?
Density = mass / volume
1.56 = 19 / volume
Cross multiply
1.56 × volume = 19
Divide both side by 1.56
Volume = 19 / 1.56
Volume = 12.18 cc
Therefore, the volume occupied by the sucrose is 12.18 cc
I want to know how to solve this question by step by step.
Question: What is the pH value of 500ml of an aqueous solution of 0.005 mol HCl ?
The pH value of 500 mL of an aqueous solution of 0.005 mole HCl is 2
How do I determine the pH of the solution?We'll begin our calculations by obtaining the molarity of the solution. Details below:
Volume of solution = 500 mL = 500 / 1000 = 0.50 LMole of HCl = 0.005 moleMolarity = ?Molarity = mole / volume
Molarity = 0.005 / 0.50
Molarity = 0.01 M
Next, we shall obtain the concentration of the hydrogen ion, H⁺ in the solution. Details below:
HCl(aq) <=> H⁺(aq) + Cl¯(aq)
From the balanced equation above,
1 mole of HCl contains 1 mole of H⁺
Therefore,
0.01 M HCl will also contain 0.01 M H⁺
Thus, the concentration of the hydrogen ion, H⁺ in the solution is 0.01 M
Finally, we shall determine the pH of the solution. Details below:
Concentration of hydrogen ion [H⁺] = 0.01 MpH of solution =?pH = -Log H⁺
pH = -Log 0.01
pH = 2
Thus, we can conclude that the pH of the solution is 2
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how does salinity differ in a river, estuary, and an ocean?
Answer:
Because fresh water flowing into the estuary is less salty and less dense than water from the ocean, it often floats on top of the heavier seawater. ... For example, a heavy spring rain, or a sustained shift in local winds, can drastically affect the salinity in different parts of an estuary.
Answer:
Because fresh water flowing into the estuary is less salty and less dense than water from the ocean, it often floats on top of the heavier seawater.For example, a heavy spring rain, or a sustained shift in local winds, can drastically affect the salinity in different parts of an estuaryuse the kinetic particle model to describe the motion and separation of the particles in solid carbon dioxide and carbon dioxide gas
In solid carbon dioxide (dry ice), the particles are held together by strong covalent bonds, so they do not move around much.
What is the carbon dioxide?
Carbon dioxide (CO2) is an odorless, colorless gas created through natural processes such as respiration, combustion and the breakdown of organic materials. As a greenhouse gas, it is a major component of the Earth’s atmosphere and plays a critical role in regulating the global climate. Carbon dioxide is made up of one carbon atom and two oxygen atoms, and is produced when fossil fuels such as coal and oil are burned. Plants and trees also use carbon dioxide as part of their photosynthesis process. Carbon dioxide is essential for life on Earth, however, too much of it can have a negative impact on our planet. As human activity has increased over the past century, so too has our production of CO2, resulting in higher concentrations of this gas in the atmosphere and contributing to global warming.
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Let us assume that Cd(OH)2(s) is completely insoluble, which signifies that the precipitation reaction with NaOH(aq) (presented in the transition) would go to completion.
Cd2+(aq)+2NaOH(aq) → Cd(OH)2(s)+2Na+(aq)
If you had a 0.300 L solution containing 0.0220 M of Cd2+(aq) , and you wished to add enough 1.25 M NaOH(aq) to precipitate all of the metal, what is the minimum amount of the NaOH(aq) solution you would need to add? Assume that the NaOH(aq) solution is the only source of OH−(aq) for the precipitation.
Answer:
The minimum amount of NaOH(aq) solution needed to add is 0.0560 L. This can be calculated by using the following equation:
Moles of Cd2+ = 0.0220 M x 0.300 L = 0.0066 mol
Moles of NaOH = 0.0066 mol x 2 = 0.0132 mol
Volume of NaOH = 0.0132 mol/1.25 M = 0.0560 L
Explanation:
QUESTION 62
Which of the following pH values represents the highest concentration of H30+ ions?
O pH 5.4
O pH 7.0
O pH 8.7
O All of the above have the same concentration of hydronium ions
O cannnot be determined with the given information
Answer:
5.4
Explanation:
The lower the pH the more H3o+ ions there are
What is the molarity of the solution formed by mixing 0.2 moles of NaOH with enough water to make 0.15 L of solution?
Answer: 0.5
Explanation:
O
Question 2 of 10
Which of the following values best classifies a bond between 2 atoms as
being covalent?
A. An electronegativity difference of greater than 2.7 between the
atoms
B. An electronegativity difference of greater than 1.7 between the
atoms
C. An electronegativity difference of less than 1.7 between the atoms
D. An electronegativity difference of less than 2.7 between the atoms
← PREVIOUS
SUBMIT
A bond between 2 atoms as being covalent an electronegativity difference of greater than 1.7 between the atoms.
What is bond?Bond is a debt instrument, which is issued by governments and corporations. These bonds are used to raise capital for various projects and investments. Bonds are a form of loan and investors are usually paid a fixed interest rate for lending their money. Bonds are typically issued for a fixed period of time, usually for a period of 5-30 years, and have a fixed maturity date. Investors receive interest payments at regular intervals and receive the principal amount of the bond at the end of the period.
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Chemical changes are changes that involve a change in the chemical identity of a substance. In other words, a new chemical or substance is created through a chemical change. A chemical change is also thought of as a chemical reaction.
Required:
Write down some ecample of a chemical change.
Answer:
The chemical change is "Frying an egg".
Explanation:
As the thermal energy is present while cooking an egg, these same components of such an egg transform their appearances as well as their consistency probably forever.Throughout the process of denaturation, the above transformation process or strategy of such a fried egg can't be completely overturned.Thus the above is the right answer.
what is the difference between refference and indicator electrode
Answer:
The key difference between indicator electrode and reference electrode is that indicator electrode responds to changes in the activity of the analyte, whereas reference electrode does not respond to changes, and its response is stable.
Explanation:
S + 6 HNO3 → H2SO4 + 6 NO2 + 2 H2O
In the above equation, how many grams of water can be made when 12.1 moles of HNO3 are consumed?
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
Nitrogen 14
Sulfur 32
Oxygen 16
The amount, in grams, of water that can be made when 12.1 moles of [tex]HNO_3[/tex] are consumed would be 72.54 grams.
Stoichiometric problemFrom the balanced equation of the reaction, the mole ratio of [tex]HNO_3[/tex] to water is 3:1.
This means that for every 3 moles of [tex]HNO_3[/tex], 1 mole of water will be produced.
3 mole [tex]HNO_3[/tex] = 1 mole water
12.1 moles HNO3 = 12.1x1/3
= 4.03 mol
Recall that: mass = mole x molar mass
The molar mass of water is 18 g/mol
Thus, the mass of 4.03 mol of water = 4.03 x 18 = 72.54 grams
In other words, going by the equation of the reaction, the mass of water that can be made when 12.1 moles of [tex]HNO_3[/tex] are consumed would be 72.54 grams.
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a) S₂08²+ I- ----> I3- + SO₂ The reaction is carried out in a basic solution. Express a balanced redox equation using the ion-electron method.
Answer:
The ion-electron method involves breaking the reactants into their component ions and transferring electrons between the ions to balance the charge and the atoms. In a basic solution, the S²⁰⁸² ion will gain two electrons to form SO₂. The I¹⁻ ion will lose one electron to form I³⁻. The balanced redox equation using the ion-electron method is:
S²⁰⁸² + 2e⁻ + 2OH⁻ → SO₂ + H₂O
I¹⁻ + e⁻ → I³⁻
The overall balanced equation is:
2S²⁰⁸² + 2OH⁻ + I¹⁻ → 2I³⁻ + SO₂ + H₂O
"Calculate the pH of a 0.15 M NaOH solution AND classify the solution of acidic, neutral, and basic"
a. 0.82 basic
b.0.82 acidic
c. 13.2 basic
d. 13.2 acidic
Answer:
la respuesta es la letra a
Assign oxidation numbers to each atom in each substance. Then check your work by summoning to zero for each compound or the charge on the ion for the polyatomic. (Please help I am awful at chemistry )
The oxidation number of the atoms in the given compounds are :
K₂O: K = + 1; O = -2;
PO₃⁻³: P = +3; O = -2
NH₃: N = -3; H = +1
Cu(NO₃)₂: Cu = +2; N = +5; O = -2
NO₃⁻¹: N = +5; O = -2
CO₂: C = +4; O = -2
KClO₃: K = +1; Cl = + 5; O = -2
O₂: O = 0
Ca(ClO₄)₂: Ca = +2; Cl = +7; O = -2
What is the oxidation number of elements?The number of electrons an atom or ion has either gained or lost in comparison to the neutral atom is known as the oxidation number or state of the atom or ion.
Group I, 2, and 3 electropositive metal atoms lose a certain number of electrons, and their positive oxidation numbers remain constant.
The oxidation number of the atoms in the given compounds are as follows:
K₂0
K = + 1
O = -2
Sum is (+1 * 2) + (-2) = 0
PO₃⁻³
P = + 3
O = -2
Sum is (+3) + (-2 * 3) = -3
NH₃
N = -3
H = +1
Sum is (-3) + (+1 * 3) = 0
Cu(NO₃)₂
Cu = +2
N = +5
O = -2
Sum is (+2) + (+5 * 2) + (-2 * 6) = 0
NO₃⁻¹
N = +5
O = -2
Sum is (+5) + (-2 * 3) = -1
CO₂
C = +4
O = -2
Sum is (+4) + (-2 * 2) = 0
KClO₃
K = +1
Cl = + 5
O = -2
Sum is (+1) + (5) + (-2 * 3) = 0
O₂
O = 0
Sum is (0 * 2) = 0
Ca(ClO₄)₂
Ca = +2
Cl = +7
O = -2
Sum is (+2) + (+7 * 2) + (-2 * 8) = 0
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The EM Spectrum is the __________ range of EM waves in order of __________ frequency and __________ wavelength.
Answer:
entire, increasing, decreasing
Explanation:
The EM Spectrum is the entire range of EM waves in order of increasing frequency and decreasing wavelength.
A chemist has one solution that is 30.% acid and another solution that is 18% acid. How much of each solution should be used to get 300. L of a solution that is 21% acid?
a. 23 L of the 30.% solution and 277 L of the 18% solution
b. 75 L of the 30.% solution and 225 L of the 18% solution
c. 131 L of the 30.% solution and 169 L of the 18% solution
d. 138 L of the 30.% solution and 162 L of the 18% solution
e. 244 L of the 30.% solution and 56 L of the 18% solution
There is a golden rule of solubility, non polar solute dissolve in non polar solvent and polar solute dissolve in polar solvent. Therefore, the correct option is option B.
What is solution?
Solution is a homogeneous mixture of two or more than two substances. A solution is a homogeneous mixture of solute and solvent molecules. Solvent is a substance that is in large amount in solution. solute is the substance which is in small amount in a solution.
There are two types of mixture that is homogeneous and heterogeneous. Solution is a homogeneous solution. The nature of solvent tells about whether the solvent is in liquid, solid or gas form.
Let amount of 30% to mix, be X
Then amount of 18% to mix = 300 - X
0.3X + 0.18(300 - X) = 0.21(300)
0.3X+ 0.18(300) - 0.18X= 0.21(300)
0.3X - 0.18X =0 .21(300) -0 .18(300)
0.12X =0 .03(300)
X=75L
Therefore, the correct option is option B.
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[H3O+] = 3.6 x 10-2 M
Answer:
om pH
The hydronium ion concentration can be found from the pH by the reverse of the mathematical operation employed to find the pH. [H3O+] = 10-pH or [H3O+] = antilog (- pH) Example: What is the hydronium ion concentration in a solution that has a pH of 8.34?
Explanation:
What's the lewis structure of NO3- and O3?
I end up finding the apparently wrong ones for both, and am probably missing out on an important notion.
The lewis structure of NO₃⁻ is trigonal planar and the Lewis structure of ozone (O₃) has a resonance form.
What are Lewis structures?Lewis structures which are also often referred to as Lewis dot formulas, Lewis dot structures, electron dot structures, or Lewis electron dot structures, depict the interactions between the atoms in a molecule as well as any lone pairs of electrons that may be present.
NO₃⁻ has a trigonal planar Lewis structure. It has one nitrogen atom, three oxygen atoms, and covalent bonds holding the three oxygen atoms together. The sp² hybridization of the nitrogen atom gives NO₃⁻- its trigonal planar structure.
Three oxygen atoms make up the oxygen allotrope known as ozone (O₃). One double bond and one single bond make up the Lewis structure of ozone. Additionally, two oxygen atoms in the Lewis structure of O3 carry charges.
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Arrange the species according to the oxidation state of nitrogen in each. Note that highest refers to the most positive oxidation state of nitrogen, whereas lowest refers to the most negative oxidation state.
A. NO3-
B. NO4+
C. N2
D. NH2OH
E. NO2-
1. Highest oxidation state
2. Lowest oxidation state
Answer:
A. NO₃⁻ ⇒ +5
B. NO₄⁺ ⇒ +9
C. N₂ ⇒ 0
D. NH₂OH ⇒ -1
E. NO₂⁻ ⇒ +3
Explanation:
To calculate the oxidation number of an element in a compound, we have to know the oxidation number of the other elements. Then, we have to consider that the sum of the oxidation number of each atom multiplied by the subscripts is equal to the net charge of the compound.
A. NO₃⁻
This is the ion nitrate. Oxygen atoms (O) has an oxidation number of -2 because it derives from an oxide. In this case, the net charge of the ion is -1. Thus, we calculate the oxidation number of N as follows:
N + (3 x (-2)) = -1
N - 6 = -1 ⇒ N= -1 + 6 = +5
B. NO₄⁺
In this case, the sum of the oxidation numbers of O and N multiplied by the subscripts is equal to +1:
N + (4 x (-2)) = +1
N - 8 = +1 ⇒ N = +1 +8 = +9
C. N₂
The oxidation number of N is 0 because N₂ is an elemental substance.
D. NH₂OH
The oxidation number of H is +1 and -2 for O. The net charge of the molecule is 0.
N + (H x 3) + (O) = 0
N + (+1 x 3) + (-2) = 0
N + 3 -2 = 0 ⇒ N = 2 - 3 = -1
E. NO₂⁻
The net charge of the ion nitrite is -1.
N + (2 x O) = -1
N + (2 x (-2)) = -1 ⇒ N = -1 + 4 = +3
Therefore:
Highest oxidation number = B. NO₄⁺ (+9)
Lowest oxidation number = D. NH₂OH (-1)
Which statement correctly describes the melting and boiling points of water?
A) They occur due to electrostatic forces between molecules
B) They are the same temperature.
C) They are 0°F and 100°F, respectively.
D) They both depend on the surface tension of water.
The temperature at which a solid transforms into a liquid at atmospheric pressure is referred to as the liquid’s melting point.
What are the melting and boiling points of water?The fact that water boils at a greater temperature than fluorine makes option C the correct choice. The melting point of water is zero degrees Celsius (32 degrees F). Depending on the atmospheric pressure, different amounts of water will boil at different temperatures. When purified water reaches its boiling point at sea level, it does so at 212 degrees Fahrenheit (100 degrees Celsius).
Compared to fluorine, water has a greater boiling point. Regarding the melting and boiling points of water and fluorine molecules, this statement is accurate.
The temperature at which a substance's solid and liquid phases are in equilibrium is known as its melting point. A temperature at which a substance's vapour pressure reaches its boiling point.
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Statement C; They are 0°F and 100°F, respectively, correctly describes the melting and boiling points of water. But Instead of F it should be degree Celsius.
What is Melting point? The temperature at which a substance changes its state from a solid to a liquid is termed as its melting point. The solid and liquid phases or states are in equilibrium at the melting point. Pressure and temperature affects a substance's melting point, which is typically reported at a standard pressure such 1 atmosphere or 100 kPa.The Melting point of water is 0°C and boiling point is 100°C.To know more about melting point visit
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3. Silances are more reactive than alkanes. Explain.
The lower bond energy of the silicanes make them more reactive than the alkanes.
What are the silicanes?We know that the members of group four has the ability to catenate and this is a property that characterizes all the elements that we can find in the group. However the extent to which the members of the group can be able to catenate is what we use to determine the stability of the bonds.
The alkanes are composed of the bonds that exist between carbon and hydrogen and the alkanes can be able to form very long chains and this can be used to explain the fact that you can be able to find the alkanes in various kinds of applications.
However, the bond energy of the silicanes is less than that of the alkanes hence they tend to be more reactive then the alkanes.
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Which term is a measurement of heat?
A. Hot
B. Warm
C. Cold
D. Temperature
Answer:
A? or maybe C?
Explanation:
Hot is heat... right? so is warm.. Am i missing something?
Answer:
The answer is D
Explanation:
I got it correct on the quiz.
1. Which of the following is a mechanical mixture?
A. shampoo
B. chocolate chip cookie dough
C. tap water
D. air
What is higher boiling point alkyne or alkyl halides??
Answer: alkyl halide
Explanation: brianlist please?
An analytical chemist is titrating 99.2 mL of a 0.6300 M solution of dimethylamine ((CH3 NH) with a 0.2500 M solution of HNO3. The p K, of dimethylamine is 3.27. Calculate the pH of the base solution after the chemist has added 213.6 mL of the HNO3 solution to it.
Answer:
pH of the base solution after the chemist has added 213.6 mL of the HNO3 solution to it is 9.96
Explanation:
Calculating the moles of dimethylamine
Moles of dimethylamine = molairty * volume in L = 0.63*0.0992 = 0.0625moles
Moles of HNO3 = molarity * volume in L = 0.25*0.2136 = 0.0534 moles
The balanced chemical equation is
(CH3)2NH + HNO3 -------------------> (CH3)2NH2^+ + NO3^-
I 0.0625 0.0534 0
C -0.0534 - 0.0534 0.0534
E 0.0091 0 0.0534
As we know ,
POH = Pkb + log[(CH3)2NH2^+]/[(CH3)2NH]
= 3.27 + log0.0534/0.0091
= 3.27+ 0.768
= 4.038
PH = 14-POH
= 14-4.038 = 9.96
Calculate the molarity of the following solution: 1.0 mole of KCI in 750.0 mL of
solution.
99 M
0.750 M
B 2.0 M
1.3 M
1.3 mol ⋅ L − 1
Molarity=
Moles of solute/ Volume of solution
How many grams of Fe2O3 can be produced from 180 g Fe ?
Answer:
257.6 grams
Explanation:
first write the formula: 4Fe + 3O2 -> 2Fe2O3
Fe molar mass is 55.8
180/55.8 = 3.226 mols
devide 3.226 by 4, then multiply by 2 which gives us 1.61 mols Fe2O3
Fe2O3 molar mass is 160
1.61 mols * 160 = 257.6 grams
Please I need help with this question.
Answer:
c?
Explanation:
Answer:
b
Explanation: