Answer:
no sé de eso perdón necesito los puntos
How many zinc atoms are contained in 3.75 moles of zinc?
2.26 × 10²⁴ atoms Zn
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightChemistry
Atomic Structure
Reading a Periodic TableAvogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.Stoichiometry
Using Dimensional AnalysisExplanation:Step 1: Define
3.75 mol Zn (Zinc)
Step 2: Identify Conversions
Avogadro's Number
Step 3: Convert
[DA] Set up: [tex]\displaystyle 3.75 \ mol \ Zn(\frac{6.022 \cdot 10^{23} \ atoms \ Zn}{1 \ mol \ Zn})[/tex][DA] Multiply/Divide [Cancel out units]: [tex]\displaystyle 2.25825 \cdot 10^{24} \ atoms \ Zn[/tex]Step 4: Check
Follow sig fig rules and round. We are given 3 sig figs.
2.25825 × 10²⁴ atoms Zn ≈ 2.26 × 10²⁴ atoms Zn
A gas occupies 135 cm3 at 143. K. At what Celsius temperature will its volume be 140 cm3? Assume that pressure remains constant.
Answer:
New temperature T2 = -124.7 °C
Explanation:
Given:
Old volume V1 = 135 cm³
New volume V2 = 140 cm³3
Old temperature T1 = 143 K
Find:
New temperature T2
Computation:
V1 / T1 = V2 / T2
135 / 143 = 140 / T2
New temperature T2 = 148.3 K
New temperature T2 = 148.3 - 273
New temperature T2 = -124.7 °C
A 1,900-m3 water tower has been cleaned with a chlorine solution. The vapors of chlorine in the tower exceed allowable concentrations for the work crew to enter and finish repairs. If the chlorine concentration is 15 mg/m3 and the allowable concentration is 0.0015 mg/L, how long must the workers vent the tank with clean air flowing at 2.35 m3/s
Answer:
t = 1862 s
Explanation:
To do this, we need first to determine the theorical detention time, which can be determined with the following expression:
t₀ = ∀/Q (1)
Where:
t₀: detention time
∀: Volume of the fluid in the reactor
Q: Flow rate in the reactor
With this time, we must use the following expression to determine the time that the workers will take to vent the tank:
C = C₀ e^(-t/t₀) (2)
From here, we must solve for time t, and the expression will be:
t = ln(C₀/C) * t₀ (3)
Now that we know the expression to use, let's solve for t. Using (1) to determine the detention time, ∀ is 1900 m³, and Q is 2.35 m³/s so:
t₀ = 1900 / 2.35 = 808.51 s
Now, let's solve for the time t. C will be 0.0015 mg/L (or 1.5 mg/m³ cause in 1 m³ we have 1000 L) and C₀ 15 mg/m³:
t = ln(15/1.5) * 808.51
t = 1861.66 s or simply 1862 sHope this helps
A balloon of hydrogen is subjected to vacuum. The initial pressure and volume of hydrogen is 0.95 atm and 0.55 L. Calculate the final pressure if the final volume is 1.22 L?
Answer:
0.43 atm
Explanation:
From the question given above, the following data were obtained:
Initial pressure (P₁) = 0.95 atm
Initial volume (V₁) = 0.55 L
Final volume (V₂) = 1.22 L
Final pressure (P₂) =?
The final pressure of the gas can be obtained by using the Boyle's law equation as follow:
P₁V₁ = P₂V₂
0.95 × 0.55 = P₂ × 1.22
0.5225 = P₂ × 1.22
Divide both side by 1.22
P₂ = 0.5225 / 1.22
P₂ = 0.43 atm
Therefore, the final pressure of the gas is 0.43 atm
The final pressure of the gas is 0.43 atm.
What is pressure?Pressure is the process of force exerted perpendicular to any surface.
Given, the Initial pressure (P₁) is 0.95 atm
The initial volume (V₁) is 0.55 L
The final volume (V₂) is 1.22 L
To find the final pressure (P₂)
By the Boyle's Law
[tex]\rm P_1V_2= P_2V_2[/tex]
[tex]\rm 0.95\times 0.55 = P_2\times1.22\\\\0.5225 = P_2 \times 1.22\\\\Divided\;both \;side\;by\;1.22\\\\P_2=\dfrac{0.5225}{1.22} = 0.43 atm.[/tex]
Thus, the final pressure of the gas is 0.43 atm.
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According to the combined gas law, pressure is inversely proportional to volume and directly proportional to temperature, and volume is directly proportional to temperature.
True
B. False
Save & Cont
Identify the acid,
Base and salt of following.
b) lime water
d) potassium oxide
coppor sulphate
( vinegar
Answer:
Lime water Ca(OH)2 is a base
Potassium oxide K2O is a basic oxide
Copper sulphate CuSO4 is a salt
And vinegar is an acid
Explanation:
Someone please help me I’m so stuck I cannot find the empty ones that were not filled in :(. I’m really confused
Answer:
Positive charges: 2
Negative charges: 1
Overall charge: +1
Explanation:
In Diagram B we have the chemical element Helium (He). You can see in the Periodic Table that He has an atomic number of 2 and an atomic mass of approximately 4.
The atomic number is equal to the number of protons, so He has 2 protons. The protons are the positive charges in the atom, so the number of positive charges is 2. That is invariable, if the number of protons - or the atomic number - of an atom changes, it changes its identity.
In the drawing, we can see that the nucleus is composed of 2 protons (2 'p' particles) and 2 neutrons (2 'n' particles). The atomic mass is calculated as the number of protons and neutrons, so 2 protons+ 2 neutrons = 4.
The surrounding particle with an 'e' is an electron. So, we have 1 electron. Electrons are negative charges, so the number of negative charges is 1.
Now, we can calculate the overall charge. We add the positive charges (protons) and negative charges (electrons). Each proton has a +1 charge, whereas each electron has a -1 charge. Finally, we perform the addition:
Overall charge= (number of protons x charge) + (number of electrons x charge) = (2 x (+1)) + (1 x (-1)) = (+2) + (-1) = +1
What is the molecular formula for a compound that is 44.87% potassium, 36.7%
oxygen, 18.0% sulfur and a molecular mass of 696g.
Answer:
Molecular formula: S4K8O16 empirical formula: SK2O4
Explanation:
First we find the moles of each by first finding grams (using the percent) and then using stoichiometry to convert into moles:
Sulfur: 696 *.18 = 125.28grams S* [tex]\frac{1 mole S}{32.065 g S} = 3.907 moles S[/tex]
Potassium: 696 *.4487 = 312.2952 *[tex]\frac{1 mole K}{39.08 g K}[/tex]= 7.99117 mole K
Oxygen: 696 * .367 = 255.432 * [tex]\frac{1 mol O}{16g O}[/tex] = 15.9654 mole O
Then we divide each value by the atom with the smallest number of moles to find the mole ratio:
3.907/3.907= 1
7.99117 mole K/ 3.907= 2.043
15.9654 mole O/ 3.907= 4.08
The empirical formula is SK2O4
To find the molecular formula, we divide the mass given (696) by the mass of the empirical formula (174.22) to get 4. We then divide each atom by 4.
Molecular formula: S4K8O16
Which statement correctly describes the conductivity of the specified material?
Gold has a high conductivity
Most plastics have a high conductivity
Most wires are made to have a low conductivity
Copper has a low conductivity
Answer:
Gold has a high conductivity
Explanation:
This is because gold is a metal that occur free in nature in rocks, alluvial , grains e.t.c. it is a transition metal and in group 11 of the periodic table do it conduct electricity. It has has conductivity because it is a metals because all metals have ability to conduct electricity. When it is pure, it is a bright, slightly reddish yellow, . It is soft, malleable.
It is a ductile metal
and ductile metal.
Answer:GOLDDDDD
Explanation:
What type of changes would you expect as you go down from the ocean's surface to
its bottom?
1.Temperature, pressure, light, and density all decrease
2.Temperature and pressure increase; light and density decrease
3.Temperature and light decrease; pressure and density increase
4.Temperature and density decrease; light and pressure increase
Answer:
answer is the 4th one
Explanation:
The type of changes one might expect as one goes down from the ocean's surface to its bottom is that temperature and light decrease; pressure and density increase.
What is pressure?Pressure is defined as the force applied on an object perpendicular to it's surface per unit area over which it is distributed.Gauge pressure is a pressure which is related with the ambient pressure.
There are various units by which pressure is expressed most of which are derived units which are obtained from unit of force divided by unit of area . The SI unit of pressure is pascal .
It is a scalar quantity which is related to the vector area element with a normal force acting on it.It is distributed over solid boundaries and across arbitary sections of fluid normal to the boundaries at every point.
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The bond order for a double bond is
Answer:
B.Two
Explanation:
The eye can see colors because:
a. the cones in the retina send signals to the brain.
b. the rods in the cornea send signals to the brain.
c. the optic nerve determines the color of the object and sends signals to the brain
d. None of the choices are correct.
Answer:
The answer is A, I think.
Answer:
the answer is A
Explanation:
The human eye and brain together translate light into color. Light receptors within the eye transmit messages to the brain, which produces the familiar sensations of color. Newton observed that color is not inherent in objects. Rather, the surface of an object reflects some colors and absorbs all the others.
PLEASE HELP!!
15POINTS!!! And brainliest
Answer: a. 3.36 L
b. 33.2 g
Explanation:
According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number [tex]6.023\times 10^{23}[/tex] of particles.
Standard condition of temperature (STP) is 273 K and atmospheric pressure is 1 atm respectively.
To calculate the number of moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex]
[tex]\text{Number of moles of} Fe_2O_3=\frac{16.0g}{159.69g/mol}=0.1mole[/tex]
[tex]3O_2(g)+4Fe(s)\rightarrow 2Fe_2O_3(s)[/tex]
a. 2 moles of [tex]Fe_2O_3[/tex] are produced by = [tex]3\times 22.4L=67.2L[/tex] of [tex]O_2[/tex]
Thus 0.1 moles of [tex]Fe_2O_3[tex] are produced by =[tex]\frac{67.2}{2}\times 0.1=3.36L[/tex] of [tex]O_2[/tex]
b. [tex]3\times 22.4L=67.2L[/tex] of [tex]O_2[/tex] react with = [tex]4\times 55.8=223.2g[/tex] of iron
Thus 10.0 L of [tex]O_2[/tex] react with = [tex]\frac{223.2}{67.2}\times 10=33.2g[/tex] of iron
You are given a sample of several compounds to separate by paper chromatography. You draw a pencil line exactly 1.00 cm from the bottom of the paper, and place a spot of sample on it. You dry the sample, then develop it in a solvent. When the chromatogram is taken out of the solvent, the paper is wet up to 9.2 cm from the bottom of the sheet. The compound you are interested in shows up as a spot 7.1 cm from the bottom of the paper. Calculate the following:
a. How far did the compound move?
b. In the same time, how far did the solvent move?
c. What is the Rf factor for the compound?
Answer:
a) 6.3 cm
b) 8.0 cm
c) 0.7875
Explanation:
(a) The compound has moved above upto 7.3 cm from the bottom of the paper. Let us assume that line is drawn at 1.0 cm mark as the origin of spot. \
Distance traversed by compound= 7.3 - 1.0 cm = 6.3 cm
(b) Distance traversed by the solvent = 9.0 - 1.0 cm = 8.0 cm
(c) The Rf = Compound Migration distance / Solvent front migration distance
= 6.3/8.0 = 0.7875
An ideal gas that is confined in piston-cylinder assembly (i.e., closed system) goes from an initial state of 1 bar at 300 K to a final state of 3 bar at 300 K by the following two-step process.
Process Path.
(Step 1) Heating at constant volume, and then
( Step 2) Cooling by holding the pressure constant.
Required:
a. Determine the initial and final molar mass.
b. Illustrate the two paths on a pressure-volume diagram. Clearly label the initial and final states, process steps and the direction of each step in the diagram.
Answer:
Explanation:
From the given information;
Using ideal gas equation:
pV = nRT
when n = 1 mol
[tex]V = \dfrac{RT}{p}[/tex]
Initial molar volume = [tex]\dfrac{8.314 \ L.bar .k^{-1}.mol^{-1} \times 300 \ K}{1 \ bar}[/tex]
Initial molar volume = 2494.2 L.mol⁻¹
Final molar volume = [tex]\dfrac{8.314 \ L.bar .k^{-1}.mol^{-1} \times 300 \ K}{3 \ bar}[/tex]
Final molar volume = 831.4 L.mol⁻¹
Observe: Select the Show polar molecule inset checkbox. The animation shows the probable location of electrons (orange dots) in a polar molecule. A. What do you notice about the distribution of the electrons? B. How does this electron distribution affect the charges of the bonded atoms?
Answer:
A. In a polar molecule, the bond is polar covalent. That is, the electrons are shared but are slightly more attracted to the more electronegative atom. That part of the molecule has a negative partial charge density, and the other has a positive partial charge density (there is no symmetry in the distribution of the electricity density)
B. Charges are not affected, the molecule is neutral because electrons are shared. A molecule has the same number of electrons and protons which balance the charges in a molecule. Since all atoms are electrically neutral, then when they combine the form of a neutral molecule.
Explanation:
To determine polarity, the geometry of the molecule must be taken into account to determine the distribution of atoms and their electronegativity (tendency to attract electrons) to determine to which points of the molecule the electrons will be most attracted.
Atoms can share electrons to form chemical bonds and thus form different compounds. In the case of non-polar molecules, when formed in a covalent bond (two atoms bond by sharing valence electrons reaching "stable octet") between equal atoms, the molecule is neutral since it has zero electric charge. In this type of bond there is no change in the oxidation number of the atoms because their shared electrons are equidistant. Covalent bonds in which the electrons are shared equally are called non-polar covalent bonds. This is because the atoms are just the same, they have the same electronegativity, so they "attract" the electrons with the same force and the electrons surround the atoms equally. The charge density distribution is the same for both, there is asymmetry in the distribution of it.
Polar molecules are formed when bonds are formed by different atoms with large differences in electronegativity. The molecule is electrically neutral as a whole because it has an equal number of positive and negative particles, but there is no symmetry in the distribution of the electricity density. A polar bond is one in which a pair of electrons is more attracted to one of the atoms. This causes one end of the molecule to acquire a positive partial charge density and the other end of the molecule to acquire a positive partial charge density and the other end of the molecule to acquire a negative partial charge.
So, as a summary:
A. In a polar molecule, the bond is polar covalent. That is, the electrons are shared but are slightly more attracted to the more electronegative atom. That part of the molecule has a negative partial charge density, and the other has a positive partial charge density (there is no symmetry in the distribution of the electricity density)
B. Charges are not affected, the molecule is neutral because electrons are shared. A molecule has the same number of electrons and protons which balance the charges in a molecule. Since all atoms are electrically neutral, then when they combine the form of a neutral molecule. Only ions do not have a neutral electrical charge because of the process of gaining or losing electrons. An ion with a positive electrical charge is called a cation, and an ion with a negative electrical charge is called an anion.
Explain how it's possible that warm temperatures can cause more snow to happen.
What is the coefficient of iron(lll) carbonate?
Fe(NO3)3 + (NH4)2CO3
? Fe2(CO3)3 + NH4NO3
A 14 year old girl is small in stature and appears younger than her age. She has not started menstruating, and her parents are concerned that she is not growing taller nor entering puberty. She has frequent headaches, and is having difficulty seeing the board at school, even though she sits near the front of the room. She feels cold, even when the room is warm, and she is often constipated. Her parents are concerned. She is in the 30th percentile for height and weight, significantly below her peers.
Required:
What hormones are of LEAST concern in this person?
a. insulin
b. GH
c. GnRH
d. TSH
Answer:
A.
B.
Explanation:
Scientist use capital letters (H) and lowercase letters (h) to represent genes. What type
of gene is represented by a capital letter?
Expressive
O Regressive
O Dominant
Recessive
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In the compound aluminum oxide, which is the cation?
Answer:
-Aluminum Oxide: The cation is Al3+ and the anion is O2-. The sum of the charges for aluminum oxide is 2(3+) + 3(2-) = 0. Thus, the formula is Al2O3. An ionic compound is named using the name of the cation followed by the name of the anion, eliminating the word ion from each.
Explanation:
A flexible container is filled with He(g) to a volume of V1 at a temperature of 150K. The container is then heated at constant pressure to a temperature of 300K. What is the final volume of the container?
a. V1/3b. V1/2c. V1d. 2V1
Answer:
a but it might also be c
Explanation:
i d k what this is
Answer:
2V1
Explanation:
A student dissolves 10.2 g of sodium hydroxide (NaOH) in 250. g of water in a well-insulated open cup. He then observes the temperature of the water rise from 21.0 °C to 32.7 °C over the course of 3.7 minutes. Use this data, and any information you need from the ALEKS Data resource, to answer the questions below about this reaction: NAOH(s) → Na" (aq) + OH (aq) You can make any reasonable assumptions about the physical properties of the solution. Be sure answers you calculate using measured data are rounded to 3 significant digits. do Note for advanced students: Its possible the student did not do the experiment carefully, and the values you calculate may not be the same as the known and published values for this reaction. O exothermic Is this reaction exothermic, endothermic, or neither? O endothermic O neither If you said the reaction was exothermic or endothermic, calculate the amount of heat that was released or absorbed by the reaction in this case. kJ Calculate the reaction enthalpy AH per mole of NaOH. mol
Answer:
A) The reaction is an exothermic reaction
B) 12.744 kJ
c) 49.976 KJ/mol . NaOH
Explanation:
A) The reaction is an exothermic reaction
B) calculate the amount of heat that was released or absorbed by the reaction in this case. kJ
Assuming : specific heat of solution = specific heat of water = 4.186 J/g°C
mass of solution = 10.2 + 250 = 260.2 g
determine The heat released in the reaction
= mass of solution * specific heat of solution * temperature change
= 260.2 * 4.186 * ( 32.7 - 21 )
= 12.744 kJ
C) Calculate the reaction enthalpy ΔH per mole of NaOH. mol
Reaction enthalpy = - heat released / ( 10.2 /40 )
= - 12.744 / ( 10.2/40 ) = - 49.976 KJ/mol . NaOH
As illustrated, the below manometer consists of a gas vessel and an open-ended U-tube containing a nonvolatile liquid with a density of 0.993 g/mL. The difference in heights of the liquid in the two sides of the manometer is 32.3mm when the atmospheric pressure is 765 mm Hg. Given that the density of mercury is 13.6 g/mL, the pressure of the enclosed gas is ________ atm. Group of answer choices
Answer:
1.01atm is the pressure of the gas
Explanation:
The difference in heights in the two sides is because of the difference in pressure of the enclosed gas and the atmospheric pressure. This difference is in mm of the nonvolatile liquid. The difference in mm Hg is:
32.3mm * (0.993g/mL / 13.6g/mL) = 2.36mmHg
As atmospheric pressure is 765mm Hg and assuming the gas has more pressure than the atmospheric pressure (There is no illustration), the pressure of the gas is:
765mm Hg + 2.36mm Hg = 767.36 mmHg
In atm:
767.36 mmHg * (1atm / 760 mmHg) =
1.01atm is the pressure of the gas
Given:
Density of mercury = 13.6 g/mLDensity of nonvolatile liquid = 0.993 g/mLDifference in height = 32.3mmAtmospheric pressure = 765 mm HgNow,
The density of Hg will be:
= [tex]\frac{13.6}{0.791}[/tex]
= [tex]17.2 \ mm[/tex]
then,
= [tex]32.3\times (\frac{1 \ mm \ Hg}{17.2} )[/tex]
= [tex]18.73 \ mm \ Hg[/tex]
hence,
The pressure will be:
= [tex]765-18.73[/tex]
= [tex]746.27 \ mm \ Hg[/tex]
= [tex]0.993 \ atm[/tex]
Thus the above answer is right.
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A 75.0 sample of a natural product isolated from alfalfa hay was dissolved in water to make 100.0 mL of solution. The solution did not conduct electricity and has an osmotic pressure of 0.246 atm at 27.0c. What is the molar mass of this compound
Answer:
Sorry i dont know
Answer:
What is the vapor pressure of an aqueous solution that has a solute mol fraction of c = 0.100? The vapor pressure of water is 25.756 mm Hg at 25°C.
12) The vapor pressure of an aqueous solution is found to be 24.9 mm Hg at 25°C. What is the mole fraction of solute in this solution? The vapor pressure of water is 25.756 mm Hg at 25°C.
9) Determine the molarity of an aspirin solution that produces an osmotic pressure of 0.0555 atm at 25°C (i = 1).
10) A saline solution is administered intravenously to patients who cannot take fluid orally and are in danger of dehydration. The osmotic pressure of this solution must match that of blood to prevent hemolysis or crenation of blood cells. What mass of sodium chloride (58.44 g/mol) is needed to produce 100.0 mL of saline solution with an osmotic pressure of 7.83 atm at a body temper
Explanation:
A metal ion (X) with a charge of 4+ is attracted to non metal ion (Z) with a charge of 3-. Which of these formulas represents the resulting compound? I need answers asap please
Answer: [tex]X_3Z_4[/tex]
Explanation:
For formation of a neutral ionic compound, the charges on cation and anion must be balanced. The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.
Here metal X is having an oxidation state of +4 called as [tex]X^{4+}[/tex] cation and [tex]Z^{3-}[/tex] is an anion with oxidation state of -3. Thus they combine and their oxidation states are exchanged and written in simplest whole number ratios to give neutral [tex]X_3Z_4[/tex]
[tex]X_3Z_4[/tex] is the formula of the resulting compound.
structure of 2,6-diiodo-4-methyl-5-propylheptane
Explanation:
2,6-Dibromo-4-isopropylphenol
2432-16-8
2,6-dibromo-4-propan-2-ylphenol
Phenol, 2,6-dibromo-4-(1-methylethyl)-
4-isopropyl-2,6-dibromophenol
Coach Scott hits a baseball with his bat to help his players with fielding
practice. The bat exerts a force on the ball, and the ball exerts an equal
and opposite force back on the bat.
A. Newton’s first law
B. Newton’s second law
C. Newton’s third law
Answer:
The ball exerts an equal and opposite force on the bat. This is the reaction force. Such an interaction pair is another example of Newton's Third Law. The baseball forces the bat in one direction and the bat forces the ball in the opposite direction.
How many significant figures
are in this number?
5.67 x 10^2
Answer:
3
Step-by-step explanation:
Hence, the given number has 3 significant figures.
hydrogen gas is collected by downward displacement of water why
Explanation:
Hydrogen is collected by downward displacement of water as it is less denser than water. Hence it comes out at the surface of water . It is insoluble in water so it does not dissolve in water. ... So, it is impossible to collect hydrogen gas in air medium.22-O