Answer:
69.66 g
Explanation:
We have the following from the question;
Density of the substance = 5.4 g/ml
Volume of substance = 12.9 ml
Mass of substance= the unknown
Since we have both density and volume of the substance, the question must be for us to obtain the mass of the substance, hence;
Density= mass/volume
Mass= Density × volume
Mass = 5.4 g/ml × 12.9 ml
Mass= 69.66 g
Chemistry is often called the __________ science because it involves the study of the materials in the universe and the changes these materials undergo
Answer:
Central
Explanation:
Chemistry is often called the central science because of connects the physical sciences, life sciences and applied sciences.
Chemistry is the study of matter and changes undergone by matter. This makes chemistry to occupy a central place in many scientific disciplines including medicine, engineering, pharmacy, geology etc. Basic knowledge of chemistry is usually required by experts in these disciplines.
does the tendency to gain electrons decrease as we go down grp 17?
Explanation:
Hi, there!!!!
Let me simply clear you..
Yes,The tendency to gain electrons (in nonmetal) decreases when we go down group 17.
The reason for above answer is when we go downwards in periodic table then the atomic size increases with the addition of number of shells and force of attraction between the nucleus and valance shell decreases. The force of attraction between the nucleus and valance shell becomes weaker due to which the force of attracting the electrons gets decreased.
So, we can say that the tendency to gain electrons decreases as we go down in periodic table.
Hope it helps....
How many primary,secondary and Tertiary carbons are in the compound. 2,3-dimethyl pentane. And
How many primary hydrogen
Answer:
5 primary carbon atoms
3 secondary carbon atoms
4 tertiary carbon atoms
6 hydrogen atoms
Which of the following sequences describes how a four-stroke engine cycle
powers the engine?
Answer: Air and fuel intake, compression and ignition, combustion and expansion, exhaust
Explanation:
Calculate the pressure drop over a 100m length due to friction when a slurry made from 1.0-mm silica particles is pumped through a horizontal 6-cm diameter pipeline (smooth pipe) at 2.5 m/s. The slurry contains 25 per cent silica by volume. The density of silica is 2700 kg/m3, rhow = 1000 kg/m3, μw = 0.001 kg/ms. Use a value of 82 for Ω. Drag coefficient for these particles,CD, may be taken as 0.44 .
For the slurry/Pipe system in question 1, estimate the deposition velocity.
Answer:
The answer is "2.78".
Explanation:
Given values:
CD= 0.44
Formula:
[tex]\bold{f_r= \frac{v^{2}}{ g(s-1)D}}[/tex]
g=9.8
s= 2.7
D= 0.06
[tex]\to f_r=\frac{2.5^2}{9.8(2.7-1)0.06}\\\\[/tex]
[tex]=\frac{2.5 \times 2.5}{9.8 \times 1.7 \times 0.06 }\\\\=\frac{6.25}{.9996 }\\\\=6.252501[/tex]
[tex]\phi = \frac{82\times v}{ \sqrt{cD} \times f_r^{-1.5}}\\\\[/tex]
[tex]= \frac{82 \times 0.25 }{ \sqrt{0.44} \times 6.25^{1.5}}\\\\=2.4285\\[/tex]
[tex]\frac{\bigtriangleup P f_1 s_1}{L} = \frac{\bigtriangleup Pf_w}{L}(1+\phi)\\[/tex]
[tex]=\frac{2fwSwv^2 (1+2.4285)}{D}\\\\[/tex]
[tex]Re= \frac{D \bar v Sw}{M_w}\\[/tex]
[tex]=\frac{0.06 \times 2.5 \times 1000 }{0.001}\\\\=\frac{150 }{0.001}\\\\= 150 \times 10^{3}\\\\= 1.50 \times 10^{5}\\\\[/tex]
[tex]fw= 0.00389[/tex]
[tex]\to \frac{\bigtriangleup P f_1 s_1}{L}[/tex]
[tex]\to \frac{2 \times 0.00389 \times 1000 \times2.5^2 \times 3.4265}{0.06}\\\\\to 2.78[/tex]
How is heat transferred through convection?
A. Heat is transferred by energy waves moving through space.
B. Heat is transferred through contact between molecules
C. Heat is transferred by light being changed into kinetic energy.
D. Heat is transferred by the movement of a liquid or gas.
Heat is transferred through convection by the movement of a liquid or gas and is denoted as option D.
What is Convection?this is defined as the process of heat flow through a fluid which include a liquid or gas.
This process doesn't involve contact between the object unlike in conduction. A typical example is the heat flow which occurs in the atmosphere thereby making it the most appropriate choice.
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What is the product of the reaction of pentanoic acid with ethanol in the presence of a strong acid?
Answer:
ethylpentanoate
Explanation:
Alkanoic acids react with alkanols in the presence of mineral acids to yield an ester and water. This is the organic analogue of the inorganic neutralization reaction. The reaction his commonly called esterification. It is an acid catalysed reaction.
The reaction of pentanoic acid and ethanol in the presence of a string acid is shown below;
CH3CH2CH2CH2COOH(aq) + CH3CH2OH(aq) ----> CH3CH2CH2CH2COOCH2CH3(aq) + H2O(l)
The name of the compound formed is ethylpentanoate.
Electric current is the flow of charged particles called ________ protons. electrons. sparks. static.
Answer: Electrons
Explanation: Electric current is the flow of charged particles called electrons.
Electric current is the flow of charged particles called electrons. Therefore, option (B) is correct.
What is electric current?An electric current can be described as the stream of charged particles such as electrons flowing through a conductor. The electric current can be determined as the net flow of the charge through the surface of the conductor.
The S.I. unit of the current is ampere which can be defined as the rate of flow of 1-coulomb charge in 1 second.
Electric current can be described as the flow of electrons through the electric conductor. The flow of the free electrons in the conductor creates the electric current.
A continuous source of electrons is needed to generate the electric current. The circuit must be closed so that the electrons can easily flow then only the electric current will flow through it.
Therefore, electrons are the charged particles whose flow produces an electric current.
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what is the light transmission of gallium?
Explanation:
the intensity of a He-Ne laser (633 nm ,5 mW) transmitted by different Gase samples is observed to change in correlation with the Nd-yttrium-aluminium-garnet laser pulse (532 nm, 7.8ns ,3mJ) which excites them
boron has two naturally occurring isotopes: boron -10 (abundance = 19.8% , mass = 10.013 amu) boron -11 (abundance = 80.2%, mass= 11.009 amu) Calculate th eatomic mass of boron
Explanation:
eam=%abudance×mass+%abudance×mass
eam=19.8%×10.013/100+80.2%×11.009/100
eam=198.2574/100+882.9218/100
eam=1081.1792/100
eam=10.811792
eam=10.812
Shalom, Guys!
The molar mass of strontium (\ce{Sr}SrS, r) is \pu{87.62 g/mol}87.62 g/mol87, point, 62, space, g, slash, m, o, l. Calculate the number of atoms in a \pu{67.5 mg}67.5 mg67, point, 5, space, m, g sample of \ce{Sr}SrS, r. Write your answer in scientific notation using three significant figures. \text{atoms Sr} ______________ atoms Sr
Love, Piper Rockelle
Answer:
4.30 × 10²⁰ atoms
Explanation:
You need to find out how many moles you have. First, convert milligrams to grams.
62.5 mg × (1 g)/(1000 mg) = 0.0625 g
Next, use the molar mass to convert from grams to moles.
0.0625 g ÷ 87.62 g/mol = 7.13 × 10⁻⁴ mol
To convert from moles to atoms, you need to use Avogadro's number (6.022 × 10²³). Avogadro's number is the number of atoms in a mole.
7.13 × 10⁻⁴ mol × 6.022 × 10²³ atoms/mol = 4.296 × 10²⁰ ≈ 4.30 × 10²⁰ atoms
You will have 4.30 × 10²⁰ atoms of strontium.
The number of Strontium atoms are 4.30 × 10²⁰ atoms
Given:
Mass of Strontium = 62.5 mg × (1 g)/(1000 mg) = 0.0625 g
Molar mass of Strontium = 87.62 g/mol
To find:
Moles of Strontium = ?
Number of moles:It is defined as given mass over molar mass.
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}\\\\\text{Number of moles}=\frac{0.0625 g}{87.62 g/mol }\\\\\text{Number of moles}=7.13 * 10^{-4} mol[/tex]
Avogadro's number is the number of atoms in a mole (6.022 * 10²³)
Conversion of moles into atoms:
[tex]7.13 × 10^{-4} mol * 6.022 * 10^{23} atoms/mol \\\\\text{ Sr atoms}= 4.296 * 10^{20} = 4.30 * 10^{20} atoms[/tex]
Thus, Strontium atoms will be 4.30 × 10²⁰ atoms.
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Compound A, C6H12O2, was found to be optically active, and it was slowly oxidized to an optically active carboxylic acid B, C6H12O3, by Ag(NH3)2. Oxidation of A by anhydrous CrO3 gave an optically inactive compound D that reacted with Zn amalgam/HCl to give 3-methylpentane. With aqueous H2CrO4, compound A was oxidized to an optically inactive dicarboxylic acid C, C6H10O4. Give structures for compounds A, B, and C; do not specify stereochemistry.
Answer:
kindly check the attach file for the drawing of the chemical structures.
Explanation:
So, we are going to start from the compound D, which is stated in the question to be optically active. Therefore, we will have that:
STEP ONE: THE OXIDATION OF COMPOUND A, C6H12O2 TO GIVE COMPOUND C.
The oxidation of compound A,C6H12O2 gives another chemical compound that is chemical compound C which is a optical inactive di-carboxylic acid. The chemical equation is given below:
C6H12O2 + H2Cr2O4 --------------------------------------------> HOOCCH2CHCH3CH2COOH.
STEP TWO: THE OXIDATION OF COMPOUND A, C6H12O2 TO GIVE COMPOUND B.
The oxidation of compound A,C6H12O2 gives another chemical compound that is chemical compound C which is a optically active acid. The chemical equation is given below:
C6H12O2 + Ag(NH3)2^+ -----------------------------> C6H12O3.
Since the question asked us to give the structures of Compound A,B and C there is no need to to show the chemical reaction for compound D.
Kindly check the picture below for the chemical structures.
Please I need help with this exercise. Does anyone know the solution to it and please with explanations:
Ag(s) + NO3–(aq) + H+(aq) → Ag+(aq) + NO(g) + H2O(l)
When the oxidation-reduction equation above is balanced, what is the coefficient for H+(aq)?
A. 1
B. 2
C. 3
D. 4
Answer:
Option D. 4
Explanation:
Ag(s) + NO3–(aq) + H+(aq) → Ag+(aq) + NO(g) + H2O(l)
To know the coefficient of H+, let us balance the equation. This is can be done as shown below:
Ag(s) + NO3–(aq) + 2H+(aq) → Ag+(aq) + NO(g) + H2O(l)
There are 3 atoms of O on the left side and a total of 2 atoms on the right side. It can be balance by putting 2 in front of H2O as shown below:
Ag(s) + NO3–(aq) + H+(aq) → Ag+(aq) + NO(g) + 2H2O(l)
There are 4 atoms of H on the right side and 1 atom on the left side. It can be balance by putting 4 in front of H+ as shown below:
Ag(s) + NO3–(aq) + 4H+(aq) → Ag+(aq) + NO(g) + 2H2O(l)
Total charge on the left side:
– 1 + 4 = +3
Total charge on the right side:
+1
To balance the charge, we simply put 3 in front of Ag and Ag+ as shown below:
3Ag(s) + NO3–(aq) + 4H+(aq) → 3Ag+(aq) + NO(g) + 2H2O(l)
Now the equation is balanced.
The coefficient of H+ is 4.
Suppose a compound is involved in three different reactions denoted R1, R2, and R3. Tripling the concentration of this reactant in all three reactions causes the rates of reaction to increase by factors of 3, 9, and 1, respectively. What is the order of each reaction with respect to this reactant? 1. R1 = 1; R2 = 2; R3 = 0
Answer:
The order of reaction is as follows, R1 = 1; R2 = 2; R3 = 0
Explanation:
The rate of a chemical reaction is the number of moles of reactants consumed per unit time or the number of moles of products formed per unit. the rate of a chemical reaction is affected by the concentration of reactants
The relationship between the rate of a chemical reaction and the concentration of its reactants is given by the rate law or equation.
Generally, the rate equation is given as;
Rate = k[A]ᵃ[B]ᵇ..., where k = rate constant which is independent of concentration of the reactants, [A] = concentration of reactant A, a = order of reaction A, [B] = concentration of reaction B, b = order of reaction B.
For the given reactions R1, R2 and R3
For R1; rate = 3, Concentration = 3[A]
3 = k[A]3ˣ
3¹ = k[A]3ˣ
Since rate is proportional to concentration, therefore, the order of reaction, x = 1
For R2; rate = 9, Concentration = 3[A]
9 = k[A]3ˣ
3² = k[A]3ˣ
Since rate is proportional to concentration, therefore, the order of reaction, x = 2
For R1; rate = 1, Concentration = 3[A]
1 = k[A]3ˣ
3⁰ = k[A]3ˣ
Since rate is proportional to concentration, therefore, the order of reaction, x = 0
Therefore, the order of reaction is as follows, R1 = 1; R2 = 2; R3 = 0
16. I don't want to go anywhere apart from
Nairobi.
A. instead
B. only
C. besides
D. than
[tex]\huge\red{AnsweR:}[/tex]
I don't want to go anywhere apart from than Nairobi.
[tex]<font color=orange>[/tex]
A. instead
B. only
C. besides
D. than_______________________
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An atom has 36 protons, 36 electrons and a mass
number of 80. How many neutrons are in this atom?
Answer:
44 neutrons
Explanation:
To find the neutrons of an atom subtract the atomic number from the mass of the atom
in this case
80-36=44
tge number of neutrons that are in that atom is 48
3. why are fire tornadoes rare ?
According to the table, a 23-30 watt CFL provides __________ lumens and is equivalent to a ________ incandescent bulb.
Answer:
The correct options are;
1. 1,600
2. 100 Watts
A 23-30 watt CFL provides 1,600 lumens and is equivalent to a 100 Watts incandescent bulb
Explanation:
Brightness is measured in lumens and watts measure energy usage therefore with the use of an energy saving light bulb, the same lumination can be obtained at a lower energy usage.
According to a comparison chart for LED Lights vs. Incandescent Light Bulbs vs. Compact Fluorescents (CFLs) from USAI lightening website 23-30 watts CFL has a light output of 1,600 and is therefore produces enough light as a 100 Watts Incandescent Light Bulb
Also according to energy.gov website, CFLs save up to 75% energy such that a 23-30 watt CFL can produce the same illumination as a 100 watt incandescent bulb
Therefore we have, a 23-30 watt CFL provides 1,600 lumens and is equivalent to a 100 Watts incandescent bulb.
Answer:
1600 lumens, 100 watt incandescent
Explanation:
100% on edge (:
Question 4 of 20:
Select the best answer for the question
4. Which of the following is a design theory from the 1980s that uses mathematics to guide computer-aided design
O A. C-K Theory
O B. General Design Theory
O C. ASE
O D. TRIZ
general design theory
It is, general design theory introduced in 1980s that uses mathematics to guide computer - aided design. Hence, option B is correct.
What is general design theory ?A variety of new design theories were developed in the 1980s as a result of technology developments like computer-aided design (CAD). The 1981 article "General design theory and a CAD system" by Hiroyuki Yoshikawa contains one of the early references to GDT.
Yoshikawa's theory "ultimately aims at elucidating the human capacity for designing in a scientific fashion, while simultaneously producing the practical information about design technique.
Many different approaches and interpretations of design theory have been made, ranging from personal statements of design principles made by designers, to philosophical conceptions of design, to a search for a design science using advanced mathematics. Hence, option B is correct.
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Scientific method quick check
Answer:
Quick you said:
-Purpose/Question
Ask a question.
-Research
Conduct background research. Write down your sources so you can cite your references. In the modern era, a lot of your research may be conducted online. Scroll to the bottom of articles to check the references. Even if you can't access the full text of a published article, you can usually view the abstract to see the summary of other experiments. Interview experts on a topic. The more you know about a subject, the easier it will be to conduct your investigation.
-Hypothesis
Propose a hypothesis. This is a sort of educated guess about what you expect. It is a statement used to predict the outcome of an experiment. Usually, a hypothesis is written in terms of cause and effect. Alternatively, it may describe the relationship between two phenomena. One type of hypothesis is the null hypothesis or the no-difference hypothesis. This is an easy type of hypothesis to test because it assumes changing a variable will have no effect on the outcome. In reality, you probably expect a change but rejecting a hypothesis may be more useful than accepting one.
-Experiment
Design and perform an experiment to test your hypothesis. An experiment has an independent and dependent variable. You change or control the independent variable and record the effect it has on the dependent variable. It's important to change only one variable for an experiment rather than try to combine the effects of variables in an experiment. For example, if you want to test the effects of light intensity and fertilizer concentration on the growth rate of a plant, you're really looking at two separate experiments.
-Data/Analysis
Record observations and analyze the meaning of the data. Often, you'll prepare a table or graph of the data. Don't throw out data points you think are bad or that don't support your predictions. Some of the most incredible discoveries in science were made because the data looked wrong! Once you have the data, you may need to perform a mathematical analysis to support or refute your hypothesis.
-Conclusion
Conclude whether to accept or reject your hypothesis. There is no right or wrong outcome to an experiment, so either result is fine. Accepting a hypothesis does not necessarily mean it's correct! Sometimes repeating an experiment may give a different result. In other cases, a hypothesis may predict an outcome, yet you might draw an incorrect conclusion. Communicate your results. The results may be compiled into a lab report or formally submitted as a paper. Whether you accept or reject the hypothesis, you likely learned something about the subject and may wish to revise the original hypothesis or form a new one for a future experiment.
A solution of HCL has percent by mass of 5%. What does it mean?
This means that in 100g of solution, there are 5g of HCl and 95g of water
-K-12 Scientific Method
3/10
A(n)
simply states what will be observed and always
true, but does not explain why.
Answer:
The correct answer is - scientific law.
Explanation:
A scientific law is an explanation to a well observed phenomenon of the world which is found true every time tested and universal proven fact, but the reason behind the phenomenon and its existence.
To explain the scientific law there will be various explanation that are called scientific theory, however these theories can not be proved.
Thus, the correct answer is - scientific law.
Which of the following is NOT a product of the electrolysis of NaCl? A. Chlorine gas B. None of these C. Hydrogen gas D. Oxygen gas
Answer:D. Oxygen gas
Explanation: because the experiment showed
A botanist measures a plant growth at 3cm over a two week period. The information she gathers is called.
Answer:
The correct answer is quantitative data.
Explanation:
The value of data in the form of numbers of counts where each set of data exhibits a specific numerical value associated with it is termed as quantitative data. This information refers to any quantifiable knowledge, which can be used for statistical analysis and mathematical calculations so that decisions of real-life can be taken based on the mathematical outcomes. The quantitative data is used to find the solutions of the queries like how often, how much, or how many.
In the given case, a botanist measured the growth of the plant for two weeks, and the outcome came in the form of numerical value. Thus, the knowledge she collected is known as quantitative data.
Suppose we want to charge a flask with 2.4 g of sugar. We put the empty flask on a balance and it is determined to weigh 150 g. What is the weight we would expect to see on the balance when we're done adding the sugar?
Answer:
152.4 g
Explanation:
given that
Weight of sugar = 2.4 g
Weight if empty flask = 150 g
All we have to do is add the weight of the empty flask with the weight of the sugar.
The sugar would be put inside an empty flask. This means that it's weight with that of the empty flask would be their new weight. Thus, the new weight is
New weight = weight of empty flask + weight of sugar
New weight = 150 g + 2.4 g
New weight = 152.4 g
therefore, the new weight is 152.4 g.
I hope this helps you
152.4 g
Given:-
Weight of sugar = 2.4 g
Weight if empty flask = 150 g
Add the weight of the empty flask with the weight of the sugar.
The sugar would be put inside an empty flask. This means that it's weight with that of the empty flask would be their new weight. Thus, the new weight is as follows:-
[tex]New weight = weight of empty flask + weight of sugar\\New weight = 150 g + 2.4 g\\New weight = 152.4 g[/tex]
Therefore, the expected weight is 152.4 g.
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Which statements describe a good hypothesis? Check all that apply.
A good hypothesis is based on one's personal opinion.
A good hypothesis can be tested.
A good hypothesis leads to a test with measureable results.
A good hypothesis does not always have to be based on prior knowledge or research.
A good hypothesis provides a possible explanation to answer a scientific question.
Answer:
- A good hypothesis can be tested.
- A good hypothesis provides a possible explanation to answer a scientific question.
- A good hypothesis does not always have to be based on prior knowledge or research.
Explanation:
The reason being because hypothesis are questions asked before the experiment. They usually involve the testable question and the experiment answers it, but not always. A good hypothesis doesn't need to have accurate results.
Answer:B : A good hypothesis can be tested. C:A good hypothesis leads to a test with measurable results. E: A good hypothesis provides a possible explanation to an answer a scientific question ( B, C, E)
Explanation:Just took the (Assignment) quiz
Me podrían ayudar con esta tarea porfa, paso a paso se los agradecería muchísimo. -El sulfuro de hidrógeno se quema con oxígeno para dar dióxido de azufre y agua. ¿Cuántos moles de dióxido de azufre se forman a partir de la reacción de 0.250 moles de 2 y 0.300 moles de 2? 2h2s(g)+3o2(g)→2so2(g)+2h2o(g)
Answer:
0.2 moles de SO₂
Explanation:
La reaccción es:
2H₂S (g) + 3O₂ (g) → 2SO₂ (g) + 2H₂O(g)
Asumimos que tenemos 0.250 moles de sulfuro y 0.3 moles de oxígeno.
En primer lugar tenemos que averiguar el reactivo limitante.
Si 2 moles de sulfuro de hidrógeno reaccionan con 3 moles de oxígeno, según la reacción.
Entonces 0.250 moles, reaccionarían con (0.250 . 3) /2 = 0.375moles
Tenemos entonces 0.3 moles de oxígeno y necesitamos 0.375 (no nos alcanza). Por lo tanto el O₂ es el limitante y ahora podemos calcular el producto formado. La ecuación nos dice:
3 moles de oxígeno pueden producir dos moles de SO₂
Entonces 0.3 moles (que son los que tenemos) de O₂ producirían:
(0.3 . 2) /3 = 0.2 moles de SO₂
Describe the reaction of an acid with an alkali.?
Your question has been heard loud and clear.
The reaction of an acid with an alkali is neutralization reaction. It is a neutralization reaction because , they both neutralize each other (means it makes them chemically inactive after reacting) and produce a salt , and maybe water too.
An example: hydrochloric acid + sodium hydroxide → sodium chloride + water
Thank you
it will neutralise because if you add both of them together with a matching Ph such as 5 and 9 equally then it will neutralise and have a Ph of 7
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Potatoes are cut into many parts, making sure that each part has at least one eye (bud). Each piece of potato will usually grow into a new potato plant. Will a new potato plant grow, if planted only with the eye? A. Yes, a full new potato plant can grow from it. B. Yes, but the new plant will take a slightly longer time to germinate. C. No, a new potato plant will not grow because the food needed for germination comes from the potato piece. D. No, a new potato plant will not grow because the leaves emerge only from the potato piece.
Answer:
b
Explanation:
the eye is the most important so it would grow but it will take some time because if we plant it with piece it has some food
tion 1/3
A white rhinoceros weighs about 1,500 pounds (lb). How many tons (T) does the rhinoceros weigh? (1 T =
A. 1.5 T
o
B. 1 T
C. 0.75 T
D. 0.5 T
Answer:
.75 Tons
Explanation:
1 Ton is equal to 2,000 pounds
