Answer:
6.7
⋅
10
23
atoms of H
Explanation:
Which of these is a source of pollution caused by humans?
A)
volcances
B)
pesticides
lightning strikes
D)
biological decay
Answer:
biological decay
Explanation:
Hope this helps
A scientist plans to find out the cause of decrease in bird population in a location. He interviews 50 people who work in the local oil mine and 45 of them believe that the mine does not affect the birds. The scientist concludes that 90 percent of people in the location believe that the local oil mine does not cause decrease in bird population. Why is the scientist's conclusion most likely unreliable? (2 points)
Group of answer choices
a. the results of the investigation cannot be repeated
b. the source of information could be biased
c. bird population cannot be measured accurately
d. the investigation is done by only one person
Answer:
Explanation:
The discharge of chromate ions (CrO42-) to sewers or natural waters is of concern because of both its ecological impacts and its effects on human health if the receiving water is later used as a drinking water source. One way in which chromate can be removed from solution is by its reaction with ferrous ions (Fe2+) to form a mixture of chromic hydroxide and ferric hydroxide solids [Cr(OH)3(s) and Fe(OH)3(s), respectively], which can then be filtered out of the water. The overall reaction can be represented as
CrO42- + 3 Fe2+ + 8 H2O --> Cr(OH)3(s) + 3 Fe(OH)3(s) + 4 H+
How much particulate matter would be generated daily by this process at a facility that treats 60 m3/h of a waste stream containing 4.0 mg/L Cr, if the treatment reduces the Cr concentration enough to meet a discharge limit of 0.1 mg/L?
Answer:
45727g
Explanation:
So, have the overall ionic equation given as the following;
CrO42^- + 3 Fe2^+ + 8 H2O ------> Cr(OH)^3(s) + 3 Fe(OH)^3(s) + 4 H^+.
So, we have (from the question) that the amount or quantity of the waste stream daily = 60m^3/h, and the waste stream daily contains waste stream containing = 4.0 mg/L Cr, and the discharge limit = 0.1 mg/L.
Step one: convert m^3/ h to L/h. Therefore, 60 m^3/h × 1000dm^3 = 60000 L/h .
Step two: Determine or calculate the the value of Cr used up.
The value of Car used up ={ 60,000 × ( 4.0 - 0.1) } ÷ 1000 = 234 g.
Step three: Determine or calculate the mass of Cr(OH)3 and the mass of Fe(OH)3.
The number of moles of Cr = 234/52 = 4.5 moles.
Molar mass of Cr(OH)3 = 103 g/mol and the molar mass of Fe(OH)3 = 106.8 g/mol.
Thus, the mass of Cr(OH)3 = 4.5 × 103 = 463.5 g.
And the mass of Fe(OH)3 = 13.5 × 106.8 = 1441.8 g.
Hence, the total = 463.5 g + 1441.8 g = 1905.3 g.
Step four: Determine or calculate the How much particulate matter would be generated daily.
The amount of the particulate that would be generated daily = 24 × 1905.3 = 45727g.
Zinc wire is added to an iron(II) nitrate solution.
Express your answer as a chemical equation. Identify all of the phases in your answer. Enter noreaction if there is no reaction.
Answer:
Zn(s) + Fe(NO₃)₂(aq) ⇒ Zn(NO₃)₂(aq) + Fe(s)
Explanation:
When metal zinc is added to an iron (II) nitrate solution, we can see the following redox reaction:
Zn(s) + Fe(NO₃)₂(aq) ⇒ Zn(NO₃)₂(aq) + Fe(s)
Zinc is oxidized since its oxidation number increases from 0 to +2.
Iron is reduced since its oxidation number decreases from +2 to 0.
plsss help!!!!! I'll give u brainlest and 10 points
Answer:
I would say it is true
Explanation:
What was one main point of Dalton’s atomic theory?
A. That atoms were made up of positive and negative charges
B. That atoms changed as they formed compounds
C. That atoms has a nucleus at the center
D. That atoms made up the smallest form of matter
The main point of Dalton’s atomic theory is that the atoms are made up the smallest form of matter. Hence Option (D) is Correct
What is Dalton's Atomic Theory ?
The 5 main points of Dalton's Atomic theory was ;
Elements are composed of extremely small particles called atoms that are indivisible and indestructibleAll atoms of a given element are identical; they have the same size, mass, and chemical propertiesAtoms of 1 element are different from the atoms of all other elementsCompounds are composed of atoms of more than 1 element. The relative number of atoms of each element in a given compound is always the same.Chemical reactions only involve the rearrangement of atoms. Atoms are not created or destroyed during chemical reactions.Therefore, The main point of Dalton’s atomic theory is that the atoms are made up the smallest form of matter. Hence Option (D) is Correct
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Answer:
D is correct
Explanation:
A compound containing only carbon, hydrogen, and oxygen is analyzed using combustion analysis. When 50.1 g of the compound is burned, 91.8 g of carbon dioxide and 25.1 g of water are collected. In order to determine the moles of carbon in the compound, first determine the moles of carbon dioxide that were produced from the combustion.
Answer:
[tex]C_{3}H_4O_2[/tex]
Explanation:
Hello,
In this case, since the carbon of the initial compound is present in the carbon dioxide product, we can compute the mass and moles of carbon in the compound:
[tex]n_C=91.8g CO_2*\frac{1molCO_2}{44gCO_2} *\frac{1molC}{1molCO_2} =2.09molC\\\\m_C=91.8g CO_2*\frac{1molCO_2}{44gCO_2} *\frac{1molC}{1molCO_2}*\frac{12gC}{1molC} =25.0gC[/tex]
Next, the mass and moles of hydrogen in the compound, is contained in the yielded amount of water, thus, we compute the mass and moles of hydrogen in the compound:
[tex]n_H=25.1gH_2O*\frac{1molH_2O}{18gH_2O} *\frac{2molH}{1molH_2O} =2.79molH\\\\m_H=25.1gH_2O*\frac{1molH_2O}{18gH_2O} *\frac{2molH}{1molH_2O} *\frac{1gH}{1molH} =2.79gH[/tex]
In such a way, the mass of oxygen comes from the mass of the compound minus the mass of carbon and oxygen:
[tex]m_O=50.1g-25.0g-2.79g=22.31gO[/tex]
And the moles:
[tex]n_O=22.31gO*\frac{1molO}{16gO}=1.39molO[/tex]
Then, we compute the subscripts by diving the moles of C, H and O by the moles of oxygen as the smallest moles:
[tex]C:\frac{2.09}{1.39}=1.5 \\\\H:\frac{2.79}{1.39}=2\\ \\O:\frac{1.39}{1.39} =1[/tex]
After that, we write:
[tex]C_{1.5}H_2O[/tex]
Which must be shown in whole number only, thereby we multiply the subscripts by 2, so the empirical formula turns out:
[tex]C_{3}H_4O_2[/tex]
Best regards.
All good experiments should be...
give reason deliquescent substance truns into liquid when exposed to atmosphere air
Element X
Is a Solid at room temperature
Is a metalloid and semiconductor of heat and
electricity
Reacts with Oxygen to form XO2,
compounds and with chlorine to form XCI4,
compounds
Has an average atomic mass that is 2.34
times greater than the standard for atomic
mass(Carbon-12)
Which is not the name of a family on the periodic table
a) Halogens
b) Noble Gases
c) Alkali Earth Metals
d) Actinides
;
Explanation: Look at the scrrn shot and you can see what is on there or not. :)))))
Actinides are not the name of the family of the periodic table.
Explanation:
In the modern periodic table :
Elements are arranged on the basis of their atomic numbersThere are 18 groups(vertical groups) and 7 periods (horizontal rows)Groups are also called families of the periodic table.Metals are present from the middle to the left-hand side of the periodic tableNonmetals are present on the upper right-hand side of the periodic tableMetalloids divide the periodic table in a zig-zag line with nonmetals on the right and metals on the left.The alkali metals are present under group 1The alkaline earth metals are present under group 2The noble gases are present under group 18The halogens are present under group 17The elements in separate two horizontal rows in the bottom are lanthanides and actinides.So, from this, we can conclude that actinides are not the name of the family of the periodic table.
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The atoms of which element will gain electrons to form an ion?
oxygen
calcium
lithium
mercury
Explanation:
Oxygen will gain electrons to form ion (O²⁻).
Calcium loses electron to form ion (Ca²⁺)
Lithium loses electron to form ion (Li⁺)
Mercury loses electron to form ion (Hg²⁺)
Here it is stated in question that the element will gain electron it means electron bears negative charge.
Therefore,
Option A is correct ✔.
Which is denser a liquid or solid why?
Answer:
Liquids are usually less dense than solids but more dense than air. Temperature can change a liquid's density. For example, increasing the temperature of water causes the molecules to spread farther apart. The farther apart the molecules are, the less dense the water is.
Answer:
Solids are usually much more dense than liquids and gases, but not always.
Explanation:
Mercury, a metallic element that is a liquid at room temperature, is denser than many solids. Aerogel, a very unusual human-made solid, is about 500 times less dense than wate
PLEASE PLEAS HELP Which of the following compounds is insoluble in water?
a) ZnSO4
b) K2SO4
c) Na2CO3
d) Ag2CO3
Answer:
Your answer is d
Explanation: silver carbonate Ag2CO3 is insoluble in water
What is the volume of 4.62 g of mercury? The density of mercury is 13.5 g/cm3.
Answer:
The answer is 0.342 cm³Explanation:
The volume of a substance when given the density and mass can be found by using the formula
[tex]volume = \frac{mass}{density} \\[/tex]
From the question
mass = 4.62 g
density = 13.5 g/cm³
We have
[tex]volume = \frac{4.62}{13.5} \\ = 0.3422222...[/tex]
We have the final answer as
0.342 cm³Hope this helps you
10. The density of aluminum is 2.70 g/mL. If the mass of a piece of aluminum is 244 grams, what is the volume of the aluminum?
Answer:
The answer is 90.37 mLExplanation:
The volume of a substance when given the density and mass can be found by using the formula
[tex]volume = \frac{mass}{density} \\ [/tex]
From the question we have
[tex]volume = \frac{244}{2.7} \\ = 90.370370...[/tex]
We have the final answer as
90.37 mLHope this helps you
A liquid has a volume of 62.7 mL and a density of 2.59 g/mL. What is its mass? (show all work)
Answer:
162.4
Explanation:
The formula for mass is density* volume so 62.7 multiplied by 2.59 equals 162.393. then you round so your anwser would be 162.4
Item 4
Which statement is one of the three parts of cell theory?
Cell organelles can be membrane-bound or not membrane-bound.
Cells make up tissues, tissues make up organs, organs make up systems, systems make up organisms.
The smallest living things are single cells, and cells are the functional units of multicellular organisms.
There are three types of cells, prokaryotic, eukaryotic plant, and eukaryotic animal.
Examples 36
A cylinder is 350cm³ long and two gases A and B have relative molecular weights of 64 and 16 respectively. If the two gases, at the same temperature and pressure, are released simultaneously at both ends determine the distance from one end at which the gases meet.
2x = 350- x
3x = 350
x = 350/x
therefore,
x = 116.67cm.
so, (350 - x)cm³ = (350- 166.67)cm³ = 233.33cm³
Hence distance covered by gas A is 116.67cm that by B is 233.33cm
Define a function compute_gas_volume that returns the volume of a gas given parameters pressure, temperature, and moles. Use the gas equation PV
Answer:
def compute_volume(pressure,moles,temperature):
volume = (8.314 * moles * temperature)/pressure
print("Volume: "+str(volume))
Explanation:
This line defines the function
def compute_volume(pressure,moles,temperature):
This line calculates the volume
volume = (8.314 * moles * temperature)/pressure
This line prints the calculated volume
print("Volume: "+str(volume))
When you cook food in a hot pan , which statement is correct? Energy from the food is transferred to the pan or energy from the food is transferred to the food.
Answer:
Not to sure! I think energy from the pan is transferred to the food? Maybe.
Explanation:
Violet light has a wavelength of 4.50 x 10-12 m. What is the frequency?*
3 points
1.5 x10^20 1/s
0.0135 1/s
6.77x10^19 1/5
3x10^8 1/s
Green light has a frequency of 6.73 x 1014 1/s. What is the wavelength?*
3 points
2.24x10^6 m
4.46x10^-7 m
2.02 x 10^23 m.
4.95 x 10^-24 m
3 points
What is the energy (Joules) of violet light with a frequency = 3.43 x 10^14
1/s? *
4.54x10^-19 J
1.99x10^-25 J
1.93 x 10^-48 J
2.27 x 10^-19 J
Answer:
Frequency = 6.67x10¹⁹ s⁻¹
Wavelength = 4.46x10⁻⁷m
e = 2.27x10⁻¹⁹J
Explanation:
To convert frequency to wavelength and vice versa we use the equation:
Wavelength = Speed of light / Frequency
Speed ligth is 3x10⁸m/s
For a wavelength of 4.50x10⁻¹²m:
4.50x10⁻¹²m = 3x10⁸m/s / Frequency
Frequency = 3x10⁸m/s / 4.5x10⁻¹²m
Frequency = 6.67x10¹⁹ s⁻¹For a frequency of 6.73x10¹⁴s⁻¹:
Wavelength = 3x10⁸m/s / 6.73x10¹⁴s⁻¹
Wavelength = 4.46x10⁻⁷mAnd energy, e, from frequency, is obtained as follows:
e = h ₓ frequency
Where h is Planck's constant, 6.626x10⁻³⁴J*s
e = 6.626x10⁻³⁴J*s*3.43x10¹⁴s⁻¹
e = 2.27x10⁻¹⁹JThe same ball is hit again and experiences a net force of 3.5 N instead. What is the acceleration of the volleyball?
Answer:
I hope this helped :)
Explanation:
a=f/m
a=3.5N/.25 kg
a=14m/s2
The acceleration of the volleyball is 14 m/s²
A force is defined to be a pull or a push acting on an object. The force exerted on an object can be said to be determined if the mass of the object is known.
It can be calculated by using the expression;
Force (F) = mass (m) × acceleration (a)
From the given information;
The net force acting on the ball after it hits again = 3.5 NLet assume that the mass of the ball is 0.25 kg since it is not given∴
The acceleration of the above expression can be computed as:
acceleration (a) = Force (F) / mass (a)
acceleration (a) = 3.5 / 0.25
acceleration (a) = 14 m/s²
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If equal volumes of a strong base and a weaker acid are mixed together, what would you expect the pH of the resulting salt to be
Answer:
Above 7
Explanation:
The equivalence point of any titration can be read off from the appropriate titration curve.
A titration curve is a plot of the pH of analyte against the volume of titrant added.
For a strong base and weak acid, the equivalence point lies above 7.
The pH of the resulting salt to be pH> 7 .
What does Equivalence point tell?The equivalence point of any titration can be read off from the appropriate titration curve. A titration curve is a plot of the pH of analyte against the volume of titrant added. It is a point in titration at which the amount of titrant added is just enough to completely neutralize the analyte solution. At the equivalence point in an acid-base titration.
For a strong base and weak acid, the equivalence point lies above 7.
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Consider the balanced equation below. Upper P Upper C l Subscript 3 Baseline + Upper C l Subscript 2 Baseline right arrow Upper P Upper C l Subscript 5. What is the mole ratio of PCl3 to PCl5? 1:1 2:1 3:5 5:3
Answer : The mole ratio of [tex]PCl_3[/tex] to [tex]PCl_5[/tex] is 1 : 1.
Explanation :
Balanced chemical reaction : It is a chemical reaction in which the number of atoms of individual elements present on reactant side must be equal to the product side.
The balanced chemical reaction is:
[tex]PCl_3+Cl_2\rightarrow PCl_5[/tex]
By the stoichiometry of the reaction we can say that 1 mole of [tex]PCl_3[/tex] reacts with 1 mole of [tex]Cl_2[/tex] to give 1 mole of [tex]PCl_5[/tex].
From this we conclude that the mole ratio of [tex]PCl_3[/tex] to [tex]PCl_5[/tex] is 1 : 1.
Hence, the mole ratio of [tex]PCl_3[/tex] to [tex]PCl_5[/tex] is 1 : 1.
Answer:
A
Explanation:
3.54 millilelvin = ? kelvin
the coefficient of 02 is needed to balance the equation C3h8+O2+3co2+4H20
Answer:The anwser is 5
Explanation:
What can you infer about the likely occurrence of the other isotopes in each of the
above elements? Explain your reasoning.
Answer:
Most common has the same or closest mass because it is closer to the original’s mass.
Explanation:
I got it from the answer key
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noble gas notation for titanium
Answer:
Titanium [Ar] 3d2 4s2
Explanation:
Which of the following represents a species with 16 protons and 18 electrons? A) Ar B) S C) S²⁻ D) Si⁴⁻ E) S²⁺ Question 5 of 40
Answer:S²⁻
Explanation:
Sulphur is in group 16. The atomic number of sulphur is 16.
However, sulphur can accept two electrons to form the sulphide ion S²⁻ which contains 18 electrons, hence the answer provided above.