Answer:
1.25M
Explanation:
What are the main sources of outdoor air pollution and how do they cause smog?
Answer:
The common sources of outdoor air pollution are emissions caused by combustion processes from motor vehicles, solid fuel burning and industry. Other pollution sources include smoke from bushfires, windblown dust, and biogenic emissions from vegetation (pollen and mold spores).
smog is produced when sunlight reacts with nitrogen oxides in the atmosphere. Nitrogen oxides come from car exhaust, coal power plants, and factory emissions. When sunlight hits these chemicals, they form airborne particles and ground-level ozone—or smog.
A 0.90 g of hydrogen chloride (HCl) is dissolved in water to make 5.0 L of solution. What is the pH of the resulting hydrochloric acid solution?
Express the pH numerically to two decimal places.
0.50g of sodium hydroxide (NaOH) pellets are dissolved in water to make 4.0L of solution. What is the pH of this solution?
Express the pH numerically to two decimal places.
Answer:
Explanation:
Mol weight of HCl = 36.5
.90 g of HCl = .90 / 36.5 mole = .02465 mole
HCl = H⁺ + Cl⁻
1 mole 1 mole
1 mole of HCl gives 1 mole of H⁺
.02465 mole of HCl will give .02465 mole of H⁺
.02465 mole of H⁺ in 5 litre soln
concentration of H⁺ = .02465 / 5 = 4.93 x 10⁻³ M
pH = - log ( 4.93 x 10⁻³ )
= 3 - log 4.93
= 3 - .693
= 2.307
= 2.31
NaOH :
Mol weight of NaOH = 40
.50 g of HCl = .50 / 40 mole = .0125 mole
NaOH = Na⁺ + OH⁻
1 mole 1 mole
1 mole of NaOH gives 1 mole of OH⁻
.0125 mole of NaOH will give .0125 mole of OH⁻
.0125 mole of OH⁻ in 4 litre soln
concentration of OH⁻ = .0125 / 4 = 3.125 x 10⁻³ M
pOH = - log ( 3.125 x 10⁻³ )
= 3 - log 3.125
= 3 - .495
= 2.505
pH = 14 - pOH
= 14 - 2.505
= 11.495 .
= 11.50
Consider two compounds. Compound A contains 15.7 g of sulfur and 18.6 g of fluorine. Compound B contains 25.4 g of sulfur and 60.2 g of fluorine. For Compound A, the ratio of fluorine to sulfur is 1.18. For Compound B, the ratio of fluorine to sulfur is 2.37. Using the Law of Definite Proportions (also called the Law of Constant Composition), could Compound A and Compound B be the same compound
Answer:
No, compound A and B are not the same compound
Explanation:
According to the law of definite proportion "every chemical compound contains fixed and constant proportions (by mass) of its constituent elements." (Encyclopedia Britannica)
We can see in the question that the ratio of flourine to sulphur in compound A is 1.18 while the ratio of flourine to sulphur in compound B is 2.37.
The two chemical compounds do not contain a fixed proportion by mass of their constituent elements therefore, they can not be same compound according to the law of definite proportions.
Titanium(IV) chloride decomposes to form titanium and chlorine, like this:
TiCl4(l) → Ti(s)+ 2Cl2(g)
At a certain temperature, a chemist finds that a reaction vessel containing a mixture of titanium(IV) chloride, titanium, and chlorine at equilibrium has the following composition:
Compound Amount
TiCl4 4.18g
Ti 1.32g
Cl2 1.08g
Required:
Calculate the value of the equilibrium constant for this reaction.
The full question is shown in the image attached to this answer
Answer:
6.2 * 10^-3
Explanation:
The reaction at equilibrium is as follows;
TiCl4(l) → Ti(s)+ 2Cl2(g)
We have to obtain the concentration of chlorine gas as follows;
[Cl2] = 1.08/70.91 g/mol × 5.2 L
[Cl2] = 0.079 M
Kc = [Cl2]^2
Kc = [ 0.079]^2
Kc = 6.2 * 10^-3
2. How many moles are there in 20 grams of Carbon?
Answer:
1.6666666666666 is the ans bcz in each mole there r 12 grams of carbon so the ans is goingtobe 20÷12
According to the mole concept, there are 1.66 moles in 20 grams of carbon.
What is a mole?
Mole is defined as the unit of amount of substance . It is the quantity measure of amount of substance of how many elementary particles are present in a given substance.
It is defined as exactly 6.022×10²³ elementary entities. The elementary entity can be a molecule, atom ion depending on the type of substance. Amount of elementary entities in a mole is called as Avogadro's number.
It is widely used in chemistry as a suitable way for expressing amounts of reactants and products.For the practical purposes, mass of one mole of compound in grams is approximately equal to mass of one molecule of compound measured in Daltons. Molar mass has units of gram per mole . In case of molecules, where molar mass in grams present in one mole of atoms is its atomic mass.
Number of moles is calculated as, mass/molar mass, thus on substitution , number of moles=20/12=1.66 moles.
Thus, there are 1.66 moles in 20 grams of carbon.
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what’s the answer please
Answer:
5 × 10⁻³ mol
Explanation:
Step 1: Given data
Volume of HCl solution (V): 25 cm³Molar concetration of the HCl solution (C): 0.2 mol/dm³Step 2: Convert "V" to dm³
We will use the conversion factor 1 dm³ = 1000 cm³.
25 cm³ × 1 dm³/1000 cm³ = 0.025 dm³
Step 3: Calculate the moles of HCl (n)
We will use the definition of molarity.
C = n/V
n = C × V
n = 0.2 mol/dm³ × 0.025 dm³ = 5 × 10⁻³ mol
Answering the following questions will help you focus on the outcomes of the experiments.
Experiment 1:
1. What happens to the water in the small tube as the water in the test tube absorbs heat?
2. Why do you think a small tube was used to observe the expansion of water?
Experiment 2:
1. Compare the circumference of the balloon before and after freezing. What is the percent increase in this
measurement?
Combined Results
Write a summary paragraph discussing this experiment and the results. Use the following questions and topics to help
guide the content of your paragraph.
Summarize the conclusions that you can draw from this experiment. Use the questions above to guide your ideas.
2. Summarize any difficulties or problems you had in performing the experiment that might have affected the results.
Describe how you might change the procedure to avoid these problems.
3. Describe at least two real-world issues or examples that illustrate the findings of this experiment.
WRITER
Word Count: of 400
OVERALL SCORE:
Answer:
ex.1
1.The water in the test tube expands as it is heated. There is only one direction to expand in, the glass tube. This glass tube is narrow so that a small change in volume will result in a considerable change in height; your signal is amplified. This is the same phenomenon as in thermometers with a glass bulb on the lower end.
2. there will be a thermal expansion will happened.
Determine whether each observation generally corresponds to a physical change or a chemical change. A liquid freezes into a solid. _________ Bubbles are produced upon mixing two solutions. __________ A precipitate is formed from two solutions. _________ A solution heats up upon mixing with another. ____________ A solid dissolves into water. __________ The color of a substance changes over time
Answer:
A liquid freezes into a solid or any other state change is a physical change. Bubbles are produced upon mixing two solutions is a Chemical change as gas formed. a precipitate is formed from two solutions is a Chemical change The conversion of a substance to another compound over time leads to a color change of the substance due to the insolubility of the compound.
It is a chemical change or properties. A solution that heats up upon mixing with another is a Chemical change known as an exothermic reaction. dissolving the substance in a liquid is a physical change physical that can be regained by evaporation or crystalization.
The map shows the average high temperatures in July for two cities in Texas.
Average July High Temperatures
Texas
Del Rio
36°C
Galveston
32°C 12
Answer:
Highest temperature which was recorded in Texas was 40 degrees.
Explanation:
Texas has variating weather. In summer Texas city turns to be very hot and during winters the city of Texas experience fall in temperature. There is very few rainfall in Texas due the climatic conditions.
Jane is sitting in the family car. Her mother is driving her from their house to the library. Jane waves as she passes her friend Marina. Which of the following is not moving with respect to Jane?
A. Marina
B. The family car
C.The library
D. Jane’s house
Answer:
B) The family car
Explanation:
I hope this helps :)
the Rockies and the Appalachians are two major mountain ranges in the United States. Which type of plate movement caused these mountain ranges to form
Answer:
Convergent
Explanation:
I don't know whether this is one of your answers but It is convergent because convergent boundaries are when two plates collide against each other which can create mountains and volcanos.
which one of the following are pure substances : water,salt water,copper,brass,air,oxygen
Answer:
Copper, Water, and Oxygen
Explanation:
Because they are compounds and compounds are pure substances <3
Answer: copper
Explanation: because all of the atoms that make up copper are copper i.e its not a compound or mixture. not made od molecules
When drawing a Bohr model for Sulfur, how many energy levels will you
draw?
5
4
3
2.
Answer:
3
Explanation:
2,8,6
This is the chemical formula for Chormium (III) nitrate Cr(NO3)3Calculate the mass percent of nitrogen in chromium(III) nitrate.
Answer:
The percent composition for nitrogen in chromium(III) nitrate is 6%.
Explanation:
The mass percent of nitrogen in chromium(III) nitrate is 17.655%.
Calculation,
Molar mass of one oxygen = 16 g
molar mass of nine oxygen = 9 × 16 g = 144 g
molar mass of one nitrogen atom = 14 g
molar mass of three nitrogen atom = 3 × 14 g = 42 g
molar mass of one chromium atom = 51.99 g
molar mass of chromium (III) nitrate molecule = 144 g + 42 g + 51.99 g = 237.99 g
Mass percent of nitrogen = mass of three nitrogen atom× 100 /mass of chromium(III)nitrate
Mass percent of nitrogen = 42 g/237.99 g × 100 = 17.655%
What is mass percentage?The percentage of the mass of the element or solute divided by the mass of the compound or solute is called mass percentage
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Put the following elements in order of increasing atomic number:
1. Strontium
2. Fluorine
3. Terbium
4. Zirconium
5. Iodine
6. Europium
7. Gallium
8. Aluminum
Answer:
Here is the answer ⬆️⬆️⬆️⬆️⬆️⬆️⬆️
The order of the given elements in increasing atomic number is given as F (9), Al (13), Ga (31), Sr (38), Zr (40), I(53) and Terbium (65).
What is atomic number?The atomic number of an element in periodic table is the number of electrons in its neutral atom. Elements are arranged in periodic table in an increasing order of atomic number from left to right.
An atom is composed of electrons, protons and neutrons. Protons are positively charged and electrons are negatively charged particles and they are equal in an atom. Thus, the total negative charge is neutralised by the negative charges.
The order for the given elements in periodic table in an increasing atomic number is F (9), Al (13), Ga (31), Sr (38), Zr (40), I(53) and Terbium (65).
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If the mercury in a manometer raises 30.0 millimeters due to a change in pressure, what is the corresponding change in pressure in atm?
Answer:
0.03947 atm
Explanation:
The relationship between mmHg and atm is given as;
1 atm = 760 mmHg
x atm = 30 mmHg
Upon solving for x;
x * 760 = 30 * 1
x = 30 / 760 = 0.03947 atm
Each polysaccharide tested gives different color results with the iodine test
3. Which state of matter has a defined shape?
HELP FAST
Answer:
Solid state of matter has a definite shapeThe answer to this is solids!
Both magnetic fields and electric fields can exert a force true or false?
Answer:
false
Explanation:
An electric field may do work on a charged particle, while a magnetic field does no work.
If a solution containing 24.0 g of a substance reacts by first-order kinetics, how many grams remain after three half-lives?
Answer:
3.0g remain
Explanation:
The half-life is defined as the time required for a reactant to decrease its concentration in exactly the half of the initial amount of reactant. Having this in mind:
In one half-life, the mass will be:
24.0g / 2 = 12.0g
In two half-lifes:
12.0g / 2 = 6.0g
And in three half-lifes, the mass that remain is:
6.0g / 2 =
3.0g remainWhat do atoms make up
२
1. A ratio of the parts of a mixture are exact true or false.
Measurements show that the enthalpy of a mixture of gaseous reactants increases by 319kJ during a certain chemical reaction, which is carried out at a constant pressure. Furthermore, by carefully monitoring the volume change it is determined that 92kJ of work is done on the mixture during the reaction. Calculate the change of energy of the gas mixture during the reaction in kJ.
Answer:
the change in energy of the gas mixture during the reaction is 227Kj
Explanation:
THIS IS THE COMPLETE QUESTION BELOW
Measurements show that the enthalpy of a mixture of gaseous reactants increases by 319kJ during a certain chemical reaction, which is carried out at a constant pressure. Furthermore, by carefully monitoring the volume change it is determined that -92kJ of work is done on the mixture during the reaction. Calculate the change of energy of the gas mixture during the reaction in kJ.
From thermodynamics
ΔE= q + w
Where w= workdone on the system or by the system
q= heat added or remove
ΔE= change in the internal energy
q=+ 319kJ ( absorbed heat is + ve
w= -92kJ
If we substitute the given values,
ΔE= 319 + (-92)= 227 Kj
With the increase in enthalpy and there is absorbed heat, hence the reaction is an endothermic reaction.
Prokaryotic cell division is a___________process involving onc chromosom.
A. simple
B. complex
C. unusual
Answer:
It’s is a simple
Explanation:the prokaryotic cell involves a simple process which intern involves one chromosom
Indicate whether each structure is aromatic, nonaromatic, or antiaromatic. Assume planarity. Compound A is a 5 membered heterocyclic ring containing two pi bonds. On one of the pi bonds is a sulfur with one lone pair and a positive charge. There is an N H group between the two pi bonds with one lone pair. Compound B is a 6 membered ring with three pi bonds. One of the ring atoms is a protonated oxygen with one lone pair. Compound C is an 8 membered ring with a double bond between carbons 2 and 3, between carbons 5 and 6 and between carbons 7 and 8. There is a positive charge on carbon 4 and a negative charge and lone pair on carbon 1. Compound D is a 7 membered ring with three pi bonds. In between two alkenes is a boron attached to a hydrogen. Comppound E is a 7 membered ring with three pi bonds. In between two alkenes is a negative charge with a lone pair.
Answer:
this some next level stuff homie
Explanation:
imma just guess 7?
The thing being described is shaped like a ring with five parts. Inside the ring, there are two special types of bonds. This has a sulfur that is positively charged and has one unshared pair, also it has an NH group with one unshared pair.
What is the structureCompound B is a substance that is made up of two or more different elements or molecules.
The thing being described has a ring with six members and three pi bonds. It has an oxygen atom with an extra proton and one extra electron. This substance is not aromatic.
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Iron-59 which is used to diagnose anaemia has a half life of 45days, what fraction of it is left in 90 days
Answer:
0.25 of the original
Explanation:
(0.5)^(90/45)
The fraction of iron-59 after 90 days is 0.25.
Iron-59 decays following first-order kinetics. Given the half-life ([tex]t_{1/2}[/tex]) of 45 days, we can calculate the rate constant (k) using the following expression.
[tex]k = \frac{ln2}{t_{1/2}} =\frac{ln2}{45day} = 0.015 d^{-1}[/tex]
For first-order kinetics, we can find the fraction of Fe ([Fe]/[Fe]₀) after and an elapsed time (t) of 90 days, using the following equation.
[tex]\frac{[Fe]}{[Fe]_0} =e^{-k \times t } = e^{-0.015 d^{-1} \times 90 d } \approx 0,25[/tex]
The fraction of iron-59 after 90 days is 0.25.
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I need help answering number 14 A B and C. Thank you!
Answer:
Explanation:
TiO2 + C + 2 CI2 → TiCI4 + CO2
(a)
(2.16 mol TiO2) x (2 mol CI2 / 1 mol TiO2) x ( 70.9064 g C/mol) = 306 g CI2
(b)
(2.16 mol TIO2) x (1 mol C / 1 mol TiO2) x ( 12.01078 g C/mol)n= 25.9 g C
(c)
Use the law of conservation of mass:
(2.16 mol TiO2) x ( 79.8660 g TiO2/mol) + (306 g CI2 + 25.9 g C = 504 g total.
Hope this help!:)
Help! I’ll give brainliest if u get it right!
Answer:
That is the Atomic mass
Explanation:
The element symbol is S, Element name is sulfur, and
Atomic number is 16
What is the molecular weight of magnesium chloride?
Answer:
Magnesium chloride/Molar mass
95.211 g/mol
Explanation:
. Which state of matter has a defined volume but no defined shape?
HELPPPP PLEASE FAST
Answer:
liquid
Explanation:
it's not plasma, solid, or gas
so I think liquid