what is the minimum amount of water is needed to dissolve 3.0 mol potassium dichromate (k2cr2o7)
Answer:
6.79 litres
Explanation:
Potassium dichromate is K2Cr2O7
Its molar mass = 294.18 g/mol
If,
1 mole = 294.18 g
3 mole = 3 x 294.18 g
= 882.54 g
Solubility of K2Cr2O7 is
4.9 g/100 mL at 0⁰c
13 g/100 mL at 20⁰c
102 g/100 mL at 100⁰c
No specific temperature is given so I have used 20⁰C since it is close to room temperature.
at 20⁰C:
13 g of K2Cr2O7 would dissolve in = 100 mL
So 1 g of K2Cr2O7 dissolves in = (100/13)
= 7.692
882.54 g of K2Cr2O7 dissolves in = 882.54 x 7.692
= 6788.59mL
We convert to litres
= 6.79 L
Somebody please help me I’m completely lost
Answer:
λ [Wavelength] = 3.04357825 m [meters]
Explanation:
Given a frequency, to find the wavelength, divide the speed of light by the frequency. Wavelength = Speed Of Light In Seconds / Frequency .
Wavelength in meters is: λ = 299,792,458 m/s / f Hz .
Then substitute in the frequency to find the wavelength: λ = 299,792,458 m/s / f Hz → λ = 299,792,458 m/s / 9.85 × 10^7 Hz → λ = 2.99792458 × 10^8 m/s / 9.85 × 10^7 → λ = 2.99792458 × 10^8 m / 9.85 × 10^7 → λ = 29.9792458 / 9.85 m → λ = 3.04357825 m
The density of Germanium is 5.32 g/cm. You
measure out 37.72 g. What is its volume?
Correct units and significant figures must be
included for full credit.
please help
Answer:
7.09 cm³
Explanation:
From the question given above, the following data were obtained:
Density of Germanium = 5.32 g/cm³
Mass of Germanium = 37.72 g
Volume of Germanium =?
The density of a substance is simply defined as the mass of the substance per unit volume of the substance. Mathematically it is expressed as:
Density = mass / volume
Thus, with the above formula, we can obtain the volume of Germanium as shown below:
Density of Germanium = 5.32 g/cm³
Mass of Germanium = 37.72 g
Volume of Germanium =?
Density = mass /volume
5.32 = 37.72 / volume
Cross multiply
5.32 × Volume = 37.72
Divide both side by 5.32
Volume = 37.72 / 5.32
Volume of Germanium = 7.09 cm³
I miss school for personal reasons and now im back and i don’t understand anything please help i dont want to fail
Answer:
E = 2.80×10⁻¹⁶ j
E = 5.37×10⁻¹⁷j
Explanation:
Given data:
Frequency of photon = 4.23 ×10¹⁷ Hz
Energy of photon = ?
Solution:
Formula:
E = h× f
E = 6.63×10⁻³⁴ js ×4.23 ×10¹⁷ Hz
Hz = s⁻¹
E = 28.0×10⁻¹⁷ j
E = 2.80×10⁻¹⁶ j
2)
Given data:
Frequency of photon = 8.10×10¹⁶ Hz
Energy of photon = ?
Solution:
E = h× f
E = 6.63×10⁻³⁴ js × 8.10×10¹⁶ Hz
Hz = s⁻¹
E = 53.7×10⁻¹⁸j
E = 5.37×10⁻¹⁷j
Which of these molecules is polar?
A. O₂
B. N2
C. BH3
D. NO
Explanation:
Then there is no net charge separation. a BH3 b CHCl3 c C2H2 d NH3. Optionally the ... Oxygen O2 c. ... BH3 2. Com Bh3 Polar Or Nonpolar In the case of non polar molecules dispersion forces or London forces are present between them.
The polar molecules is NO.
What is polar molecule?A polar molecule is one that has one end that is slightly positive and the other end that is slightly negative. Ionic or polar covalent bonds can form in polar molecule. A dipole is a molecule that has two poles. The dipole moment is the outcome of measuring the amount of polarity in a molecule.
NO molecule, In the periodic table, nitrogen is to the right of oxygen. Nitrogen has a lower electronegative potential than oxygen. All N-O bonds are polar, with the oxygen atom having a higher electron density. The uneven distribution of electrons in the NO molecule is quite minor. When a molecule is non-polar, the electrons are shared evenly, resulting in a non-polar bond, or the polar bonds are symmetric. So, oxygen, nitrogen and boron trihydride molecules are non-polar molecule.
Hence the correct option is D.
To know more about polar molecule, here,
https://brainly.com/question/11405437
#SPJ2
A chemistry graduate student is given of a hydrocyanic acid solution. Hydrocyanic acid is a weak acid with . What mass of should the student dissolve in the solution to turn it into a buffer with pH
Here is the full question:
A chemistry graduate student was given 500 mL of a 1.60 M hydrocyanic acid (HCN) solution. Hydrocyanic acid is a weak acid with [tex]K_a = 4.9 \times 10^{-10}[/tex]. What mass of KCN should the student dissolve in the HCN solution to turn it into a buffer with pH = 9.16?
Answer:
36.85 g
Explanation:
From the given information above:
Recall that number of moles of HCN = mass of HCN / molar mass of HCN= mass of HCN / molar mass of HCN
Therefore;
the number of moles of HCN = [tex]\dfrac{500 \times 1.60}{1000}[/tex]
the number of moles of HCN = [tex]\dfrac{800}{1000}[/tex]
the number of moles of HCN = 0.8
The acid dissociation constant [tex]K_a[/tex] = [tex]4.9 \times 10^{-10}[/tex]
Thus the pKa = [tex]- log (4.9 \times 10^{-10})[/tex]
pKa = 9.31
However, the pH is given as:
[tex]pH = pKa + log \bigg ( \dfrac{KCN}{HCN} \bigg )[/tex]
[tex]9,16 =9.31 + log \bigg ( \dfrac{KCN}{0.8} \bigg )[/tex]
[tex]9,16 -9.31 =log \bigg ( \dfrac{KCN}{0.8} \bigg )[/tex]
[tex]-0.15 =log \bigg ( \dfrac{KCN}{0.8} \bigg )[/tex]
KCN = 0.566 mol
The standard molar mass of KCN = 65.11 g/mol
Thus, the mass of KCN = number of moles of KCN × molar mass of KCN
the mass of KCN = 0.566 × 65.11
the mass of KCN that the student needs to dissolve in HCN is = 36.85 g
Which of these choices is true about any map that shows the entire world?
Multiple Choice | 1.00pts
Land is always brown, and the ocean is always blue.
Lines of latitude and longitude are always perpendicular.
Some distortion exists somewhere in the map.
The map is always rectangular.
Answer:
Some distortion exists somewhere in the map.
Explanation:
Any map that shows the entire world will have some distortion somewhere in the map. This is because we are transforming a spherical body to a flat rectangular dimensional surface.
The earth is a 3-dimensional body and a map, is usually 2-dimensionalShapes are usually distorted in order to accommodate this transposition. Some continents will appear smaller or bigger than expected. The nature of the projection used will determine the inherent distortion.what is the same about map view and cross section
Answer:
(a) Map view and (b) cross-section view of location results for lower and upper groups overlapping with faults. Green dashed lines, magenta dots and blue dots refer to preexisting faults, lower events and upper events, respectively. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)
(a) Map view and (b) cross-section view of location results for lower and upper groups overlapping with faults. Green dashed lines, magenta dots and blue dots refer to preexisting faults, lower events and upper events, respectively. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)
which two body systems work together to deliever oxygen to the cells
Answer:
circulatory and respiratory
Explanation:
your welcome :)
What's the structure of CI2O? Is it polar or non-polar? hellp
Answer:
its polar
Explanation:
Joshua has learned that the human body is made up of many body systems that work together to function for life which of the following does not provide an example of two human body systems working together A heart pumps oxygen-rich blood from the lungs to the body B storing waste products for later illumination C  shivering in response to sensing cold D hormones are released into the bloodstream
Answer:
Explanation:B storing waste materials
which substance is translucent
Answer:
Paper, some plastics, frosted glass, etc.
Explanation:
A sample has a nitrate concentration of 4.39 mg/L (4.39 ppm nitrate). Calculate its molar concentration (in moles/L). (This primarily involves unit conversions).
Answer:
[tex]0.0000708\ \text{mol/L}[/tex]
Explanation:
The nitrate concentration of the sample = [tex]4.39\ \text{mg/L}=4.39\times 10^{-3}\ \text{g/L}[/tex]
Molar mass of [tex]NO^-_3=62.0049\ \text{g/mol}[/tex]
The molar concentration is obtained when we divide the concentration by its molar mass in the approriate units.
[tex]\dfrac{4.39\times 10^{-3}}{62.0049}=0.0000708\ \text{mol/L}[/tex]
The molar concentration is [tex]0.0000708\ \text{mol/L}[/tex]
In which layer of the atmosphere do meteors burn up?
A: Thermosphere
B: Stratosphere
C: Mesosphere
D: Troposphere
Answer:
C Mesosphere
Explanation:
the meteors will travel through the exosphere and thermosphere without much trouble due to the lack of air in those layers but when they hit the middle layer which is the mesosphere there are enough gases to cause friction and create heat burn up in the mesosphere
(I did research on a helpful site! I hope this helps)
:)
Write a balanced half-reaction for the reduction of solid manganese dioxide MnO2 to manganese ion Mn 2 in acidic aqueous solution. Be sure to add physical state symbols where appropriate.
Answer:
2 e⁻ + 4 H⁺(aq) + MnO₂(s) → Mn²⁺(aq) + 2 H₂O(l)
Explanation:
Let's write the half-reaction for the reduction of solid manganese dioxide MnO₂ to manganese ion Mn²⁺ in acidic aqueous solution.
MnO₂(s) → Mn²⁺(aq)
To balance the oxygen atoms, we will add 2 moles of water on the right side. To compensate for the hydrogen atoms added, we will add 4 hydrogen ions on the left side.
4 H⁺(aq) + MnO₂(s) → Mn²⁺(aq) + 2 H₂O(l)
Finally, we will balance the charges by adding 2 electrons on the left side.
2 e⁻ + 4 H⁺(aq) + MnO₂(s) → Mn²⁺(aq) + 2 H₂O(l)
What is the mass percent of water in nickel(II) sulfate hexahydrate?
The mass percent of water in nickel (II) sulfate hexahydrate is 41.129 %.
The chemical formula of nickel (II) sulfate hexahydrate is NiSO₄.6H₂O.
The mass of 1 mole of NiSO₄.6H₂O is:
[tex]mNiSO_4.6H_2O = mNi + mS + 10mO + 12mH \\= 58.69 g + 32.07 g + 10 \times 16.00 g + 12 \times 1.01 g = 262.88 g[/tex]
The mass of H₂O in 1 mole of NiSO₄.6H₂O is:
[tex]mH_2O = 6 \times (2mH + mO) = 6 \times (2 \times 1.01 g + 16.00 g) = 108.12 g[/tex]
The mass percent of H₂O in NiSO₄.6H₂O is:
[tex]\% H_2O = \frac{mH_2O}{mNiSO_4.6H_2O} \times 100 \% = \frac{108.12 g}{262.88 g} \times 100 \% = 41.129 \%[/tex]
The mass percent of water in nickel (II) sulfate hexahydrate is 41.129 %.
You can learn more about percent composition here: https://brainly.com/question/17505281
What is the formula mass of (NH4)3 PO4? (Show work)
Answer:
Mass = 149g
Explanation:
N3 = 3x14u = 42
H12 = 12x1u = 12
P = 1x31u = 31
O4 = 4x16u = 64
42+12+31+64 = 149g
NiCl2 —> Ni + Cl2
What is the type of reaction? Also the reactants and products?
Match the scientist with his discovery or contribution.
Match Term Definition
J. J. Thomson A) Electrons
John Dalton B) Atoms
Ernest Rutherford C) Neutrons
James Chadwick D) Protons
Answer:
J. J. Thomson - Electrons
John Dalton - Atoms
Ernest Rutherford - Protons
James Chadwick - Neutrons
Answer:
Look at the picture :)
Which of the following would you get from playing too much tennis?
A. Muscular Dystrophy
B. Cerebral Palsy
C. Tendonitis
D. ALS
Answer:
a
Explanation:
Of the three states of matter, molecules are moving the fastest and are the farthest apart in a what?
Answer:
Molecules are moving the fastest and are the farthest apart in the gaseous phase.
Explanation:
The most reactive groups in the Periodic Table are
A) Group 1 and 2 B) Group 1 and 17 C)Group 1 and 18 D)Group 17 and 18
Answer:
B) Group 1 and 17
Explanation:
alkali metals and the halogens are the most reactive because of valence electrons
What is the percent m/m concentration of an aqueous solution of sodium nitrate in which there are 24.34 grams of solute in 138.87 grams of solvent
Answer:
14.9%m/m
Explanation:
The percent m/m concentration of a solution (%m/m) indicates the grams of solute there are in 100 g of solution. It can be calculated as follows:
[tex]%m/m= \frac{mass of solute (g)}{mass of solution(g)} x 100[/tex]%m/m= mass of solute(g)/mass of solution(g) x 100
As the solution is composed by solute + solvent, the mathematical expression can be transformed in:
[tex]%m/m= \frac{mass of solute (g)}{mass of solution(g)} x 100[/tex]%m/m= mass of solute(g)/(mass of solute + mass of solvent (g) )x 100
= 24.34 g[tex]%m/m= \frac{mass of solute (g)}{mass of solution(g)} x 100[/tex]/(24.34 g + 138.87 g) x 100
= 24.34 g/(163.21 g) x 100
= 14.9%
[tex]%m/m= \frac{mass of solute (g)}{mass of solution} x 100 = \frac{mass of solute (g)}{mass of solute (g) + mass of solvent (g)}[/tex]
Which susbatances are combinations of nonmetals
Discuss each of the following observations: (a) The [CoCl4]2– ion is a regular tetrahedron but [CuCl4]2– has a flattened tetrahedral structure. (b) The electronic absorption spectrum of [CoF6]3– contains two bands with maxima at 11,500 and 14,500 cm–1.
Answer:
See explanation
Explanation:
a) Look at the electronic configuration of both species;
Cu^2+- [Ar] 3d9 4s0
Co^2+- [Ar] 3d7 4s0
We can now see that a Jahn Teller effect occurs in [CuCl4]2– due to its d9 configuration. This Jahn-Teller distortion causes the symmetry of [CuCl4]2– to change from tetrahedral T
d to trigonal pyramidal C3v.
b) This is a consequence of Jahn-Teller effect in [CoF6]3– which makes the Co-F bonds lie along the z-axis and become elongated in comparison to the remaining four Co-F bonds
A chemist makes up a solution by dissolving 39.0 g of Mg(NO3)2 in enough water to produce a final solution volume of 257 mL. To calculate the molarity of the solution, what additional information is needed
Answer:
[tex]M=1.02M[/tex]
Explanation:
Hello.
In this case, since the molarity of a solution is computed as the moles of solute over volume of solution:
[tex]M=\frac{n_{solute}}{V}[/tex]
Since the volume of the solution is 257 mL or also 0.257 L, we compute the moles of solute, which is magnesium nitrate (molar mass = 148.3 g/mol), as shown below:
[tex]n_{solute}=39.0gMg(NO_3)_2*\frac{1molMg(NO_3)_2}{148.3 gMg(NO_3)_2}=0.263molMg(NO_3)_2[/tex]
Thus, the required molarity turns out:
[tex]M=\frac{0.263molMg(NO_3)_2 }{0.257L}\\ \\M=1.02M[/tex]
Best regards.
mixed nuts, halo-halo and buko sald
are exam
examples of what kina
of mixtured
Answer:
heterogeneous mixture
Explanation:
I'm not sure what halo halo or buko is but with mixed nuts you can see the mixture elements so that would be heterogeneous.
If you can't see the individual pieces in a mixture like ex: milk. that is a homogenous mixture.
Pillow lava forms:
underwater
on land
on mountain tops
Which of the folio rock formation processes in NOT matched correctly?
A) Melting & cooling = Ingenious rock formation
B) Heat & pressure = metamorphic rock formation
C) Magma cooling = metamorphic rock formation
D) sediments being deposited, compacted & cemented together = sedimentary rock formation
E) Weathering, erosion, deposition, compaction & cementation = sedimentary rock formation
Answer:
I got e but you might want to wait for someone else to answer it just incase...
Answer:
Magma cooling = metamorphic rock formation
Explanation:
Did you mean formation not folio?
if 22.0 aluminum chloride is added to 26.0 g of silver nitrate, how many g of that solid product is expected to form
Answer:
21.95 g of AgCl.
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
AlCl3(aq) + 3AgNO3(aq) —> 3AgCl(s) + Al(NO3)3(aq)
Next, we shall determine the masses of AlCl3 and AgNO3 that reacted and the mass of AgCl produced from the balanced equation. This is illustrated below:
Molar mass of AlCl3 = 27 + (3×35.5) = 133.5 g/mol
Mass of AlCl3 from the balanced equation = 1 × 133.5 = 133.5 g
Molar mass of AgNO3 = 108 + 14 + (3×16) = 170 g/mol
Mass of AgNO3 from the balanced equation = 3 × 170 = 510 g
Molar mass of AgCl = 108 + 35.5 = 143.5 g/mol
Mass of AgCl from the balanced equation = 3 × 143.5 = 430.5 g
From the balanced equation above,
133.5 g of AlCl3 reacted with 510 g of AgNO3 to produce 430.5 g of AgCl.
Next, we shall determine the limiting reactant. This can be obtained as follow:
From the balanced equation above,
133.5 g of AlCl3 reacted with 510 g of AgNO3.
Therefore,
22 g of AlCl3 will react with =
(22 × 510)/133.5 = 84.04 g of AgNO3.
Thus, we can see that it will require a higher mass (i.e 84.04 g) of AgNO3 than what was given (i.e 26 g) to react completely with 22 g of AlCl3. Therefore, AgNO3 is the limiting reactant and AlCl3 is the excess reactant.
Finally, we shall determine the mass of the solid product (AgCl) produced from the reaction.
In this case the limiting reactant will be used because, it will produce the maximum yield of the reaction since all of it is used up in the reaction.
The limiting reactant is AgNO3 and the mass of AgCl produced can be obtained as follow:
From the balanced equation above,
510 g of AgNO3 reacted to produce 430.5 g of AgCl.
Therefore, 26 g of AgNO3 will react to produce = (26 × 430.5)/510 = 21.95 g of AgCl.
Thus, the mass of the solid product (AgCl) produced is 21.95 g