KOH added : 7.5 ml
Further explanationBuffer solution of weak acid HCOOH and strong base KOH
Reaction
initial = 100 ml 0.1 M HCOOH = 10 ml mol HCOOH, and x mlmol of KOH
KOH + HCOOH ⇒ COOHK + H₂O
x 10
x x x x
- 10-x x x
[HCOO - ] = 3[HCOOH]
[tex]\tt \dfrac{x}{x+100~ml}=3\dfrac{10-x}{x+100}\\\\x=3(10-x)\\\\x=30-3x\\\\4x=30\rightarrow x=7.5~ml[/tex]
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]
sodium hydroxide is extremely soluble in water. a saturated solution contains 678.57 grams of sodium hydroxide 1.00 liter of solution. calculate the molarity of a saturated sodium hydroxide solution.
Answer:
M = 17 M
Explanation:
Given data:
Mass of sodium hydroxide = 678.57 g
Volume of solution = 1.00 L
Molarity of solution = ?
Solution:
Molarity is used to describe the concentration of solution. It tells how many moles are dissolve in per litter of solution.
Formula:
Molarity = number of moles of solute / L of solution
Number of moles of sodium hydroxide:
Number of moles = mass/molar mass
Number of moles = 678.57 g /40 g/mol
Number of moles = 17 mol
Molarity:
M = 17 mol/1.00 L
M = 17 mol/L
M = 17 M
WILL MARK BRAINLIEST:
Identify the dichotomous key: plz answer:::: Each of these aliens belongs to the same genus. What is their genus?
Answer:
Alienus
Explanation:
Everything in outer space including stars, planets, and galaxies
O A. Solar System
B. Universe
OC. Galaxy
D. Biosphere
I
Answer:
Universe.
Explanation:
Biosphere is just a planet. Solar system contains planets and star. Galaxy holds multiple solar systems only. Universe hold everything, biospheres, solar systems, and galaxies. I hope this helps :D
Answer:
B.
Explanation:
A solar system is IN a galaxy. Its not A.
A Galaxy doesnt have other galaxies in it. Its not c
A biosphere is only referring to earth. its not D.
Therefore, it is B. A universe is everything in outer space including stars, planets, and galaxies.
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
The enthalpy change of reaction 1 is -114 kJ mol-1
reaction 1
2NaOH(aq) + H2SO4(aq)
→ Na2SO4(aq) + 2H2O(1)
By using this information, what is the most likely value for the enthalpy change of reaction 2?
reaction 2
Ba(OH)2(aq) + 2HCl(aq) → BaCl2(aq) + 2H2O(1)
Answer:
-114kJ mol-1
Explanation:
Definition of the enthalpy change of neutralization: the energy released with the formation of 1 mole of water when neutralization takes place between an acid and a base.
Since both reactions yield the same number of moles of water, the answer should be -114kJ mol-1.
The statement for the enthalpy change of reaction 2 is "-114 kJ"
What is enthalpy change?The change in enthalpy (ΔH) is a quantity of heat of a system. The enthalpy change is the amount of heat that enters or exits a system during a reaction.
One equivalent of hydrogen ions is neutralised with one equivalent of hydroxide ions in the reaction 1,
NaOH(aq) + HCl(aq) → NaCl(aq) + H2O(l)
The change in enthalpy is given as -114 kJ.
Two equivalents of hydrogen ions are neutralised with two equivalents of hydroxide ions in the reaction 2,
Ba(OH)2 + H2SO4 (aq) → BaSO4 (s) + 2H2O (l)
But, that primary ionic reaction is same for both the reaction in which hydrogen ion combines with hydroxide ion to generate a water molecule. So, the enthalpy change of reaction 1 would be exactly same as for reaction 2.
The neutralization enthalpy comes out to be -114 kJ.
Hence the correct answer is -114 kJ.
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1. If a solution of sodium chloride has 22.3 g of
NaCl, and a volume of 2.00 L, what is its molarity?
We are given:
Mass of NaCl in the given solution = 22.3 grams
Volume of the given solution = 2 L
Number of Moles of NaCl:
We know that the number of moles = Given mass / Molar mass
Number of moles = 22.3 / 58.44 = 0.382 moles
Molarity of NaCl in the Given solution:
We know that Molarity of a solution = Moles of Solute / Volume of Solution(in L)
Molarity = 0.382 / 2
Molarity = 0.191 M
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.
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Determine if a homogeneous solution forms when each pair of substances is mixed Check all that apply . CCL 4 H 2 O Br 2 and CCl 4 CH 3 CH 2 OH and H 2 O
Answer:
Explanation:
bc
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.
A sample of poisonous carbon monoxide gas, CO, contains 2.50 g carbon and 3.33 g oxygen. The
unknown gas X is analyzed and it is determined to be made of 0.75 g carbon and 2.00 g oxygen. Are
these data an example of the law of definite proportions, the law of multiple proportions, or neither?
What does the data tell you about the identity of gas X?
Answer:
Explanation:
In carbon monoxide ,
2.5 g of carbon reacts with 3.33 g of oxygen
In unknown gas X ,
.75 g of carbon reacts with 2 .00 g of oxygen
2.5 g of carbon will react with 6.66 g of oxygen in X gas .
Ratio of oxygen in two compounds , reacting with same mass of carbon
= 3.33 : 6.66
= 1 : 2 , a simple ratio
It follows law of multiple proportions .
First gas is CO or carbon monoxide
X gas is CO₂ or carbon dioxide .
In this gas , ratio of oxygen reacting with same amount of carbon is doubled .
Convert 85.02g to mg (1 mg=10^-3g)
Answer:
85,020 milligrams
Explanation:
Multiply the mass value by 1,000
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.
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What volume of a 0.181 M nitric acid solution is required to neutralize 25.1 mL of a 0.167 M calcium hydroxide solution
Answer:
46.32 mL
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
2HNO₃ + Ca(OH)₂ —> Ca(NO₃)₂ + 2H₂O
From the balanced equation above,
The following data were obtained:
Mole ratio of the acid, HNO₃ (nA) = 2
Mole ratio of the base, Ca(OH)₂ (nB) = 1
Next, we shall write out the data obtained from the question. This includes:
Molarity of the acid, HNO₃ (Ma) = 0.181 M
Volume of the base, Ca(OH)₂ (Vb) = 25.1 mL
Molarity of the base, Ca(OH)₂ (Mb) = 0.167 M
Volume of the acid, HNO₃ (Va) =?
Finally, we shall determine the volume of the acid, HNO₃ as shown below:
MaVa/ MbVb = nA/nB
0.181 × Va / 0.167 × 25.1 = 2/1
0.181 × Va / 4.1917 = 2
Cross multiply
0.181 × Va = 4.1917 × 2
0.181 × Va = 8.3834
Divide both side by 0.181
Va = 8.3834 / 0.181
Va = 46.32 mL
Therefore, the nitric acid, HNO₃ required for the reaction is 46.32 mL
what is a stethoscope
Explanation:
A stethoscope is used to listen to sounds that the heart , lungs , blood flow , intestines make.
Which macro nutrient is made up of carbon and hydrogen elements join together in long groups called hydrocarbons?
Answer:
organic molecules made up of carbon and hydrogen elements joined together in long groups called hydrocarbons. The arrangement of these hydrocarbon chains, and their interaction with each other, determines fat type.
The study of chemicals and their bond is called chemistry.
The correct answer is lipid.
Those molecules which are present in the cell more than the amount of 800 daltons are called macromolecules.
According to the question, the correct answer is lipid because in lipid all the molecules are made up of a long chain of carbon and hydrogen join together.
For example, palmitic is made up of 16 carbon compounds.
Hence, the correct answer is lipid.
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Which statement describes a way electromagnetic waves are different from
mechanical waves?
A. Electromagnetic waves can travel only through matter.
B. Electromagnetic waves can carry energy over a distance,
0 0
C. Electromagnetic waves can transfer matter through empty space.
D. Electromagnetic waves can travel through empty space,
Answer:
D. Electromagnetic waves can travel through empty space.
Explanation:
Answer:
its drum roll please D.) Electromagnetic waves can travel through empty space
Explanation:
please wash your hands and stay safe 2021
11
SKILL LEVEL
Proficient
Which substance conducts electricity in the liquid state but is a
poor conductor in the solid state?
a: Li₂O
b: SeCl2
C: P205
d: Hg
Answer:
a: Li₂O
Explanation:
Ionic compounds are good conductors only in liquid state. They do not conduct electricity in their solid state.
The only ionic compound from the given choices is Li₂O.
Ionic compound do not conduct electricity in their solid state because their ions are locked and are not free to move about their fixed lattice. In liquid states, they go into solution and they are free to move thereby acting as a good conductor.
How many grams of copper (II) hydroxide can be prepared from 2.4 grams of copper (II) nitrate (Cu(NO3)2 ) and excess sodium hydroxide?
Answer:
percentage yield = 67%
Explanation:
Mass of Cu(NO₃)₂ = 15.25 g
Mass of NaOH = 12.75 g
Percentage yield = ?
Solution:
Cu(NO₃)₂ + 2NaOH → Cu(OH)₂ + 2NaNO₃
Moles of Cu(NO₃)₂:
Number of moles = mass/ molar mass
Number of moles = 15.25 g /187.56 g/mol
Number of moles = 0.08 mol
Moles of NaOH :
Number of moles = mass/ molar mass
Number of moles = 12.75 g / 40 g/mol
Number of moles = 0.32 mol
Now we will compare the moles of Cu(OH)₂ with NaOH and Cu(NO₃)₂. NaOH : Cu(OH)₂
2 : 1
0.32 : 1/2×0.32 = 0.16 mol
Cu(NO₃)₂ : Cu(OH)₂
1 : 1
0.08 : 0.08
The number of moles produced by Cu(NO₃)₂ are less so it will limiting reactant.
Mass of Cu(OH)₂:
Mass = number of moles × molar mass
Mass = 0.08 mol × 97.6 g/mol
Mass = 7.808 g
Theoretical yield = 7.808 g
Percent yield:
percentage yield = Actual yield/ theoretical yield × 100
percentage yield = 5.23 g/ 7.808 g × 100
percentage yield = 0.67 × 100
percentage yield = 67%
1.3 grams of copper (II) hydroxide can be prepared from 2.4 grams of copper (II) nitrate (Cu(NO₃)₂) and excess sodium hydroxide.
Let's consider the following balanced double displacement reaction.
Cu(NO₃)₂ + 2 NaOH ⇒ Cu(OH)₂ + 2 NaNO₃
2.4 g of Cu(NO₃)₂ (molar mass 187.56 g/mol) react. The reacting moles of Cu(NO₃)₂ are:
[tex]2.4 g \times \frac{1mol}{187.56g} = 0.013 mol[/tex]
The molar ratio of Cu(NO₃)₂ to Cu(OH)₂ is 1:1. The moles of Cu(OH)₂ produced from 0.013 moles of Cu(OH)₂ are:
[tex]0.013molCu(NO_3)_2 \times \frac{1molCu(OH)_2}{1molCu(NO_3)_2} = 0.013 molCu(OH)_2[/tex]
The molar mass of Cu(OH)₂ is 97.56 g/mol. The mass corresponding to 0.013 moles of Cu(OH)₂ is:
[tex]0.013 mol \times \frac{97.56g}{mol} = 1.3 g[/tex]
1.3 grams of copper (II) hydroxide can be prepared from 2.4 grams of copper (II) nitrate (Cu(NO₃)₂) and excess sodium hydroxide.
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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)
2. Suppose 13.7 g of C2H2 reacts with 18.5 g O2 according to the reaction below. C2H2(g) + O2(g) → CO2(g) + H2O(ℓ) a. What is the mass of CO2 produced? b. What is the limiting reagent?
Answer:
Mass of CO₂ produced = 20.328 g
Oxygen is limiting reagent.
Explanation:
Given data:
Mass of C₂H₂ = 13.7 g
Mass of O₂ = 18.5 g
Mass of CO₂ produced = ?
What is limiting reagent = ?
Solution:
Chemical equation:
2C₂H₂ + 5O₂ → 4CO₂ + 2H₂O
Number of moles of C₂H₂:
Number of moles = mass /molar mass
Number of moles = 13.7 g/ 26.04 g/mol
Number of moles = 0.526 mol
Number of moles of O₂:
Number of moles = mass /molar mass
Number of moles = 18.5 g/ 32 g/mol
Number of moles = 0.578 mol
Now we will compare the moles of CO₂ with C₂H₂ and O₂
C₂H₂ : CO₂
2 : 4
0.526 : 4/2×0.526 = 1.052
O₂ : CO₂
5 : 4
0.578 : 4/5×0.578 = 0.462
The number of moles of CO₂ produced by O₂ are less thus oxygen will be limiting reactant.
Mass of CO₂ produced:
Mass = number of moles × molar mass
Mass = 0.462 mol × 44 g/mol
Mass = 20.328 g
Brad pushed a shopping cart directly toward his car at a constant velocity for 6.0 seconds.
During that time, Brad's daughter jogged past him at 2.4 meters per second, and the cart
moved 6.6 meters. What was the cart's velocity?
Answer:
Watch Naruto that's the answer
Explanation:
When a metal reacts with hydrogen carbon dioxide gas is produced? True or False
Answer:
false
Explanation:
"When a metal reacts with hydrogen carbon dioxide gas is produced" statement is false.
What is a chemical equation?A chemical reaction is a representation of symbols of the elements to indicate the amount of substance and moles of reactant and product.
Generally, metals do not react with hydrogen. But some metals like sodium, potassium, calcium and magnesium force the hydrogen atom to accept the electrons given by these elements and form salt-like ionic solid compounds called metal hydrides.
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Which situation describes a chemical change?
A. Clay pressed into a mold takes on the shape of the mold.
B. Baking soda added to vinegar gives off carbon dioxide gas.
C. Chocolate changes from a solid to a liquid when heated.
D. Rubbing pencil lead onto paper changes the color of the paper.
Answer:
C
Explanation:
I just took the test
Answer:
B
Explanation:
5. What is the pH of an aqueous solution of the strong acid, Perchloric Acid (HClO4), with a concentration of 0.007 M?
How many atm is 25.0 psi?
Answer:
1.70115 or 1.70 atm
Explanation:
1 psi is equal to 0.068046 atm.
A ballon that contains 0.75 l of gad at 25 c is cooled to - 100 c. Calculate the new volume of the baloon
Answer:
0.44L
Explanation:
Given parameters:
Initial volume = 0.75L
Initial temperature = 25°C = 273 + 25 = 298K
Final temperature = -100°C = 273 + (-100) = 173K
Unknown:
New volume of the balloon = ?
Solution:
According to Charles's law;
"the volume of a fixed mass of a gas varies directly as its absolute temperature if the pressure is constant".
Mathematically;
[tex]\frac{V_{1} }{T_{1} }[/tex] = [tex]\frac{V_{2} }{T_{2} }[/tex]
V and T are temperature values
1 and 2 are the initial and final states
Insert the parameters and solve;
[tex]\frac{0.75}{298}[/tex] = [tex]\frac{V_{2} }{173}[/tex]
298V₂ = 129.75
V₂ = 0.44L
Theodor Schwann was a German scientist who wanted to understand how different types of cells worked and performed functions in different tissues. He was one of the first to theorize that all living things are made up of cells.
Rudolf Virchow was a German doctor who wanted to discover the origin of diseases. He accepted the idea that all living things are made up of cells and extended the idea to theorize that many diseases are the result of bacterial cells infecting the body.
The example described above suggests that
A.
scientific discoveries are never made by doctors.
B.
scientists always have the same goals when making related discoveries.
C.
German scientists were the first to disprove cell theory.
D.
people with different goals can make contributions to scientific knowledge.
D. People with different goals can make contributions to scientific knowledge
Both Schwann and Virchow had different thoughts and ideas. Schwann wanted to understand how cells worked - Virchow wanted to know the origin of diseases. Different goals.
Answer:
D
Explanation:
I got it right on studyisland
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
Considering the patterns you have noticed in this activity, which statement best explains why a compound with the molecular formula CH3 doesn't exist in nature?
A. Hydrogen typically needs four bonds to reach a noble gas configuration.
B. Carbon needs more than just three bonds to reach a noble gas configuration. C. The chemical CH3 does not react with other substances because of its high stability.
D. CH3 has three double bonds, which fails to give it a noble gas configuration
Answer:
The answer is B
Explanation:
I had the same question and I chose B and it was correct.
Answer:
B. Carbon needs more than just three bonds to reach a noble gas
Explanation:
PLATO ANSWER
PLATO EXPLANATION-
Each hydrogen atom can make only one bond, but a carbon atom needs four bonds to be stable. Therefore, three hydrogen atoms are not enough for the carbon atom to make four bonds.