Answer:
The International System of Units (SI) is originated in France by frenches and originally was called a metric system of measurements. It provides definitions of various units of measurement such as weight, distance, electric current, temperature, and others which is widely accepted in the different fields of science and technology.
It is the system that is extended and derived from the french metric system of measurement is accepted in 1960 by convention 44 nation of the world to use particular unit of measurement worldwide to avoid confusion.
An example of a chemical change A. Fireworks B. Chemical reaction C. Chemical change D. Energy
A chemistry student needs 30.0 of tetrahydrofuran for an experiment. By consulting the CRC Handbook of Chemistry and Physics, the student discovers that the density of tetrahydrofuran is 0.889 g x cm^-3 . Calculate the volume of tetrahydrofuran the student should pour out.
Answer: The volume of tetrahydrofuran the student should pour out is 33.7 ml
Explanation:
Density is defined as the mass contained per unit volume.
[tex]Density=\frac{mass}{Volume}[/tex]
Given : Mass of tetrahydrofuran = 30.0 grams
Density of tetrahydrofuran = [tex]0.889gcm^{-3}[/tex]
Putting in the values we get:
[tex]0.889gcm^{-3}=\frac{30.0g}{Volume}[/tex]
[tex]Volume=\frac{30.0g}{0.889gcm^{-3}}=33.7cm^3=33.7ml[/tex] [tex](1cm^3=1ml)[/tex]
Thus volume of tetrahydrofuran the student should pour out is 33.7 ml
Write the balanced equation for the formation of the Grignard reagent from bromobenzene.
Answer:
hello your question is incomplete attached below is the complete question
Write the balanced equation for the formation of the Grignard reagent from bromobenzene. Include all reagents and products BUT NOT SOLVENTS.
answer : attached below
Explanation:
I mol mg + 1 mol bromobenzene = 1 mol Grignard
attached below is the balanced equation for the formation of the Grignard reagent from bromobenzene
g Does a reaction occur when aqueous solutions of chromium(III) sulfate and ammonium phosphate are combined
Answer:
See explanation
Explanation:
The reduction potential of Cr III is more negative than that of NH4+ hence NH4+ will be displaced by Cr III from a solution of its salt according to the following reaction equation;
Cr2(SO4)3 + 2(NH4)3PO4--------->2CrPO4 + 3(NH4)2(SO4)
Hence;
A reaction occurs when aqueous solutions of chromium(III) sulfate and ammonium phosphate are combined.
How many neutrons are contained in nitrogen -15?
Answer:
7 neutrons
Explanation:
Plzzzzzzzzzzz helpppppp
Answer:
True
Explanation:
If someone's genetics were Bb, B would be the dominant trait and b would be the recessive trait.
Answer:
True
Explanation:
That's how it works
What is the answer to this?
one if them is phosphate
The raw water supply for a community contains 18 mg/L total particulate matter. It is to be treated by addition of 60 mg alum (Al2(SO4)3 14H2O) per liter of water treated. Essentially, all the added alum precipitates represented by the following reaction:
Required:
a. For a total flow of 8000 m^3/d, compute the daily alum requirement and the concentration of solids in the water following alum addition, assuming the alum all precipitates as Al(OH)3(s).
b. The water is initially at pH 7.5 and has ALK=40 mg/L as CaCO3. It is desired to maintain solution pH at 6.5 or higher. Will the pH be in the acceptable range after the chemical addition and Al(OH)3(s) precipitation?
c. What will the pH be if the treated solution is bubbled with air, so that it reached equilibrium with atmospheric CO2?
Solution :
Given :
The steady state flow = 8000 [tex]$ m^3 /d $[/tex]
[tex]$= 80 \times 10^5 \ I/d $[/tex]
The concentration of the particulate matter = 18 mg/L
Therefore, the total quantity of a particulate matter in fluid [tex]$= 80 \times 10^5 \ I/d \times 18 \ mg/L $[/tex]
[tex]$= 144 \times 10^6 \ mg/g$[/tex]
[tex]$= 144 \ kg/d $[/tex]
If 60 mg of alum [tex]$ [Al_2(SO_4)_3.14 H_2O] $[/tex] required for one litre of the water treatment.
So Alum required for [tex]$ 80 \times 10^5 \ I/d $[/tex]
[tex]$= 80 \times 15^5 \ I/d \times 60 \ mg \ alum /L$[/tex]
[tex]$= 480 \times 10^6 \ mg/d $[/tex]
or 480 kg/d
Therefore the alum required is 480 kg/d
1 mg of the alum gives 0.234 mg alum precipitation, so 60 mg of alum will give [tex]$ = 60 \times 0.234 \text{ of alum ppt. per litre} $[/tex]
[tex]$= 14.04 $[/tex] mg of alum ppt. per litre
480 kg of alum will give = 480 x 0.234 kg/d
= 112.32 kg/d ppt of alum
Daily total solid load is [tex]$= 144 \ kg/d + 112.32 \ kg/d$[/tex]
= 256.32 kg/d
So, the total concentration of the suspended solid after alum addition [tex]$= 18 \ mg/L + 60 \times 0.234 $[/tex]
= 32.04 mg/L
Therefore total alum requirement = 480 kg/d
b). Initial pH = 7.4
The dissociation reaction of aluminium hydroxide as follows :
[tex]$Al(OH)_3 \rightleftharpoons Al^{3+} + 3OH^{-} $[/tex]
After addition, the aluminium hydroxide pH of water will increase due to increase in [tex]$ OH^- $[/tex] ions.
Therefore, the pH of water will be acceptable range after the addition of aluminium hydroxide.
c). The reaction of [tex]$CO_2$[/tex] and water as follows :
[tex]$CO_2 (g) + H_2O (l) \rightarrow H_2CO_3$[/tex]
For the atmospheric pressure :
[tex]$p_{CO_2} = 3.5 \times 10^{-4} \ atm $[/tex]
And the pH is reduced into the range of 5.9 to 6.4
Suppose 2.27g of lead(II) nitrate is dissolved in 300.mL of a 52.0mM aqueous solution of ammonium sulfate. Calculate the final molarity of nitrate anion in the solution. You can assume the volume of the solution doesn't change when the lead(II) nitrate is dissolved in it.
Answer:
0.0457M is molarity of nitrate anion in the solution.
Explanation:
Molarity is defined as the ratio between moles of solute (In this case, nitrate ion) and liters of solution (The total volume of the solution is 300.0mL = 0.300L).
Thus, we need to convert mass of Lead(II) nitrate to moles using its molar mass (Molar mass Pb(NO₃)₂: 331.2 g/mol). Moles of Pb(NO₃)₂ = 1/2 Moles of NO₃⁻:
Moles Pb(NO₃)₂ and moles of NO₃⁻:
2.27g * (1mol / 331.2g) = 0.006854 moles Pb(NO₃)₂ * (2moles NO₃⁻ / 1mol Pb(NO₃)₂) = 0.0137moles NO₃⁻
Molarity is:
0.0137 moles NO₃⁻ / 0.300L =
0.0457M is molarity of nitrate anion in the solution. What is absolute zero? What is the temperature of absolute zero on the Kelvin and Celsius scales?
Answer: Absolute zero is denoted as 0 K on the Kelvin scale, −273.15 °C on the Celsius scale, and −459.67 °F on the Fahrenheit scale.
Explanation: the lowest temperature that is theoretically possible, at which the motion of particles that constitutes heat would be minimal. It is zero on the Kelvin scale, equivalent to –273.15°C or –459.67°F.
Answer:
Absolute Zero is the absence of heat energy, aka the lowest possible temperature. In Kelvin absolute zero is just 0 because the Kelvin scale starts at 0. In celsius it is -273.15 degrees
How many valence electrons would an element with an electron configuration ending in p5 have?
Answer: 7 valence electrons
Explanation:
Electronic configuration represents the total number of electrons that a neutral element contains. We add all the superscripts to know the number of electrons in an atom.
The electrons are filled according to Afbau's rule in order of increasing energies.
Valence electrons are the number of electrons constituting the outermost shell of an atom.
Thus the electronic configuration could be :
[tex]1s^22s^22p^5[/tex]
Thus the outermost orbit is 2 which has (2+5)= 7 electrons. Thus there are 7 valence electrons.
Can anyone help me ASAP
Answer: Balance, multiply, find ratio
Explanation:
Balance the equation to be able to multiply correctly and accurately, multiply, and this will give you the molar ratio
( urgent help needed!! 50pts + brainliest )
What particle remains when uranium-238 undergoes alpha decay?
A. thorium-234
B. protactinium-234
C. plutonium-234
D. neptunium-234
Answer:
Thorium-234 option a .......
238 4 234
U --> α + Th
92 2 90
The answer is A Thorium.
Which of the following is the most accurate definition of heredity?
A. The storage of information in the nucleus of every cell in the body
B. The passage of genetic instructions from one generation to another
C. The relationship of one organism to another by evolutionary history
D. The adaptation of an organism for better survival in a new habitat
Answer:
The passage of genetic instructions from one generation to another
Explanation:
The one that is most accurate definition of heredity is the passage of genetic instructions from one generation to another. The correct option is B.
What is the reason behind heredity?Heredity, also known as inheritance or biological inheritance, is the transmission of traits from parents to their offspring; the offspring cells or organisms acquire the genetic information of their parents through reproduction.
Genes are composed of DNA (deoxyribonucleic acid), which contains instructions for cell function as well as the characteristics that distinguish you.
Each biological parent gives you half of your genes, and you may inherit a gene mutation from one or both of your parents. Sometimes genes change as a result of problems with the DNA (mutations).
Hereditary theory holds that many physical characteristics can be passed down from generation to generation via DNA, by passing on a set of instructions or genes in DNA to offspring. You pass on the physical characteristics that you have.
Thus, the correct option is B.
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The _______________ react with the _______________ elements to form different compounds like lithium fluoride (LiF) and sodium chloride (NaCl). _______________ have a full valence level and do not combine with other elements.
Answer: Alkali metals, halogens, noble gases
Explanation:
Ionic compounds are made of ions- charges. In LiF and NaCl, the first element has a +1 and the second element has a charge of -1. Elements that are +1 are alkali metals and elements that are -1 are halogens. Noble gases have full octets in their outermost valence shell, and since they're full it's so stable so it doesn't react with anything.
Which of the following plant structures provides most of the water necessary for photosynthesis?
а. roots
b. leaves
chloroplasts
d. stomata
Answer:
Explanation:
a:)
The plant structure that provides most of the water necessary for photosynthesis is the leaves. The correct option is b.
What is photosynthesis?Through a process known as photosynthesis, green plants and some other animals transform light energy into chemical energy. The main, readily available, non-recyclable component of photosynthesis is sunlight.
Plants use their roots to draw water from the soil. Water is necessary for photosynthesis, which primarily takes place in a plant's leaves, as you probably already know.
Chloroplasts, which are found in the mesophyll of the leaves, are where photosynthesis occurs. The chlorophyll in the thylakoids, which are located inside the chloroplast, absorbs the various colors of light to produce energy.
Therefore, the correct option is b. leaves.
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Predict the products of the reaction below. That is, complete the right-hand side of the chemical equation. Be sure your equation is balanced and contains state symbols after every reactant and product.
HNO3+ H2O → ______
Answer:
HNO₃ (aq) —> H⁺ (aq) + NO₃¯ (aq)
Explanation:
From the question given above
HNO₃ + H₂O —> ?
Nitric acid, HNO₃ reacts with water, H₂O to form aqueous solution of nitric acid as illustrated below:
HNO₃ + H₂O —> HNO₃ (aq)
Nitric acid is a strong acid and, so will ionised completely when dissolved in water. This is illustrated below:
HNO₃ (aq) —> H⁺ (aq) + NO₃¯ (aq)
Why is an ice cube less dense than liquid water?
O A. Molecules in ice have less space between them than molecules in liquid water
O B. Molecules in ice are more spread out than molecules in liquid water.
O C. Ice molecules have less mass than water molecules.
O D. Ice molecules have more mass than water molecules.
Anwser is B. Just got correct.
Answer:
B hope this helps
Explanation:
The density of a substance describes how closely its molecules are packed. Despite the fact that ice is a solid form, an ice cube contains many pores in and the molecules are more spread in the state than that in liquid state of water.
What is density?Density of a substance is the measure of its mass per unit volume. It describes how closely packed its molecules within a given volume. If the molecules have enough space to spread they will be less dense.
The objects which are less dense than water will float in it. Whereas which are having more density will sink on it. Ice floats on water because, ice is less dense than water.
An ice cube has a pore structure and one ice cube contains fewer water molecules and which are spread through the porous structure. Therefore, water in liquid state is more dense than ice.
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Differentiate between a mixture and a compound. Provide an example of each using the characteristics outlined in the lesson to support your example.
Explanation:
A compound is a pure substance formed by the combination of two or more kinds of atoms or elements joined together in a definite grouping.
An mixture is an impure substance made up of different types of substances.
Here are some of the differences between them;
A compound is a pure substance whereas a mixture is an impure substance. All parts of a compound are homogenous throughout where a mixture is often heterogeneous. Compounds have definite compositions whereas mixtures do not have a definite composition. Compounds cannot be easily broken down by physical means whereas in mixtures, separation is by physical means. Compound have a unique set of physical properties whereas mixtures have varied set of physical properties.Examples of compounds are water, sodium chloride, hydrochloric acid
Mixtures are air, ocean water, alloys, et.c
Which gas is most abundant in Earth’s atmosphere?
Answer:
nitrogen
Explanation:
The atmosphere contains many gases, most in small amounts, including some pollutants and greenhouse gases. The most abundant gas in the atmosphere is nitrogen, with oxygen second. Argon, an inert gas, is the third most abundant gas in the atmosphere. Why do I care?
nitrogen is the most abundant gas in the atmosphere
A leak in the air conditioning of an old car releases Chlorofluorocarbons (CF2C\2) into the air.
Each month the car releases 62g of CF2Cl2. How much fluorine is emitted into the air each
YEAR by this car?
Answer:
[tex]m_F=234gF[/tex]
Explanation:
Hello!
In this case, given that one molecule of CF2Cl2 contains two moles of atoms of fluorine, we can set up the following dimensional analysis to compute the emitted fluorine each year by the considered car:
[tex]m_F = \frac{62gCF_2Cl_2}{1month}*\frac{12months}{1year}* \frac{1molCF_2Cl_2}{120.91gCF_2Cl_2}*\frac{2molF}{1molCF_2Cl_2} *\frac{19.0gF}{1molF} \\\\m_F=234gF[/tex]
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Acetic acid and water react to form hydronium cation and acetate anion, like this:
HCH3CO2(aq)+H2O-------->H3O(aq)+CH3CO2-(aq)
Imagine 226.mmol of CH3CO2- are removed from a flask containing a mixture of HCH3CO2,H2O ,H3O and CH3CO2- at equilibrium, and then answer the following questions.
1. What is the rate of the forward reaction before any HCH3CO2 has been removed from the flask?
a. zero.
b. greater than zero, but less than the rate of the reverse reaction.
c. greater than zero, and equal to the rate of the reverse reaction.
d. greater than zero, and greater than the rate of the reverse reaction.
2. What is the rate of the forward reaction just after the HCH3CO2 has been removed from the flask?
a. zero.
b. greater than zero, but less than the rate of the reverse reaction.
c. greater than zero, and equal to the rate of the reverse reaction.
d. greater than zero, and greater than the rate of the reverse reaction.
3. What is the rate of the forward reaction when the system has again reached equilibrium?
a. zero.
b. greater than zero, but less than the rate of the reverse reaction.
c. greater than zero, and equal to the rate of the reverse reaction.
d. greater than zero, and greater than the rate of the reverse reaction.
4. How much less hch3co2 is in the flask when the system has again reached equilibrium?
a. none.
b. some, but less than 217mmol.
Answer:
1. c. greater than zero, and equal to the rate of the reverse reaction.
2. d. greater than zero, and greater than the rate of the reverse reaction.
3. c. greater than zero, and equal to the rate of the reverse reaction.
4. b. some, but less than 217 mmol.
Explanation:
Dynamic equilibrium is only attainable in a closed system. When dynamic equilibrium has been attained in a closed system, the rate of forward reaction becomes exactly the same as the rate of reverse reaction.
If the equilibrium of the system is disturbed by removal of one of the products, the equilibrium position will shift to the right thereby yielding more reactants.
After some time, equilibrium is reestablished and rate of forward reaction is once again equal to the rate of reverse reaction.
As the reaction proceeds, the reactants are used up and their concentration at equilibrium is usually less than the initial concentration at the commencement of the reaction.
Where would you find an angular unconformity?
Answer:
What are Types of Unconformity?
Disconformity. A disconformity is an unconformity between parallel layers of sedimentary rocks which is a period of erosion or non-deposition.
Nonconformity. A nonconformity exists between sedimentary rocks and metamorphic or igneous rocks when the sedimentary rock lies above and was deposited on the pre-existing and eroded metamorphic or igneous rock.
Angular unconformity. An angular unconformity is an unconformity in which horizontally parallel strata of sedimentary rock are deposited on tilted and eroded layers, resulting in angular discordance with the horizontal …
Explanation:
Answer:
For geologists, one of the most famous angular unconformity is the Grand Unconformity in the Grand Canyon of Arizona. Here tilted sedimentary rocks of Precambrian age are overlain by younger sedimentary rocks of Phanerozoic age.
Explanation:
Question: Write a short paragraph on how you separate mixtures at home?
Answer:
We can separate mixtures at home by following ways;
Mixtures can be separated using a variety of techniques.
Chromatography involves solvent separation on a solid medium.
Distillation takes advantage of differences in boiling points.
Evaporation removes a liquid from a solution to leave a solid material.
Filtration separates solids of different sizes.
A chiral C5H10O ether reacts with excess hot HI to give a C5H10I2 product. When this product is treated with KOH, 1,3-pentadiene is produced. What is the structure of the starting ether
Answer:
See answer and picture below
Explanation:
In this case, the key to get an idea of how is the starting ether is with the final product and the empirical formula of the ether.
First, the empirical formula of the ether gives us information of the structure of the ether. This ether could be either an alkene, alkane or cycloalkane.
Alkane cannot be because alkane's formula is CnH(2n+2), so it's either an alkene or cycloalcane (CnH2n).
However, as we can see, it reacts with HI in excess, so, it cannot be an alkene because in this case the acid will react with the double bond of the ether too forming another product. This discart the fact that the ether has a double bond. So it has to be a cycloalkane.
As the innitial structure it's an ether, it should be either a cyclohexane or cyclopentane with a methyl group attached. So, how can we know which of these structures is? well, we can actually do the reaction with both reactants and see which match. In the attached picture you have the answer.
Hope this helps.
The starting ( original ) structure of ether after the entire reaction above is given in the picture attached to this answer sheet
EtherEthers are also one of the classes of organic compounds that contain an ether group ( an oxygen atom connected to two alkyl or aryl group )
They have the general formula R–O–R′, where R and R′ represent the alkyl or aryl groups.
Ethers; however can as well be classified into two categories:
If the alkyl groups are the same on both sides of the oxygen atom, then it is a simple or symmetrical etherIf they are different, the ethers are called mixed or unsymmetrical ethersLearn more about organic compounds:
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Which of these is a typical property of a substance that is composed of atoms that are held together by covalent bonds?
Answer) It does not conduct electricity in any form. Consider the location of barium, chlorine, iodine, and strontium on the periodic table. It conducts electricity when it is dissolved in water.
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A rocky hill cracks after water settles and freezes. Several trees on the hill tilt due to the very slow downhill movement of rock and soil. The movement occurs over a long distance.
Which type of mass movement does this describe?
creep
landslide
mudflow
slump
Answer:
A. Creep
Explanation:
Creep is usually defined as a mass movement process where the rock and other particles are forced to move slowly downward along a slope that is mostly covered with softer sediments and broken rock fragments. It results in the tilting of trees, poles, and gravestones.
The type of mass movement described above is a creep.
What is creep movement?Creep movement refers to the slow downslope of different objects and/or materials that occurs on a particular slope surface.
In nature, creep movement is common to describe the slow tilt movement of different materials such as trees and poles on a hillside.
Creep movement occurs on a geological scale, ie, this movement may take hundreds of years.
In conclusion, the type of mass movement described above is a creep.
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Which compounds have the empirical formula CH20?
a. C2H402
b. C3H603
c. CH202
d. C5H1005
e C6H1206
Answer:
Answer is A.
Explanation:
I hope it's helpful!
What type of energy does the
mitochondrion provide the cell?
chemical energy (ATP)
light energy
thermal energy
sound energy
The answer is multiple choice
Answer:
Thermal
Explanation:
I think im not quite sure but since thermal is basically heat energy, I assume it would be thermal energy
An isotype has the same number of _____ but a different number of ______ than other atoms of the same element
electrons, protons, neutrons are the answer choices for both
Answer:
BTS
Explanation:
