What is a cold front? What kind of weather can you expect there?
What is the chemical formula of potassium manganate vii
Answer:
Explanation:Visit this site for any assignments assistance
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Câu 1: Trong các dung dịch sau, dung dịch nào làm quỳ tím đổi màu xanh?
A. HCl B. H2SO4 C. NaOH D. NaCl
Câu 2: Bazơ nào dưới đây là bazơ không tan?
A. KOH B. NaOH C. Cu(OH)2 D. Ca(OH)2
Câu 3: Trong các chất sau đây, chất nào không phải là muối?
A. HCl B. KCl
C. NaOH
C. Cu (OH)
A. HCl
What is the AHsol for LiF → Lit + F-? The lattice energy is -1,036 kJ/
mol, the enthalpy of hydration for Lit is -499
kJ/mol, and the enthalpy of hydration for F-is-431 kJ/mol. Use A Hooi = -A Hat + AHhydr.
0-968 kJ/mol
-106 kJ/mol
106 kJ/mol
1,966 kJ/
mol
The heat of hydration is defined as the heat absorbed or evolved when one mole of a substance undergoes hydration. The heat of solution is the enthalpy change associated with he dissolution of a solute. The lattice energy is the heat. Lattice energy is the energy released when the components of the lattice are brought together from infinity.
Hence the heat of solution for LiF → Li^+ + F- is -1966 kJ/mol
Given that;
Heat of hydration = ΔH solution – ΔH lattice energy
Where,
ΔH solution = Heat of the solution
ΔH lattice energy = Lattice energy of the solution
The heat of solution or enthalpy of dissolution is defined as the enthalpy change associated with the dissolution of a solute in a solvent
From the formula above;
ΔH solution = Heat of hydration + ΔH lattice energy
Heat of hydration = [(-431) + (-499)] = -930 kJ/mol
ΔH solution = (-930) + (-1,036) = -1966 kJ/mol
Hence the heat of solution for LiF → Li^+ + F- is -1966 kJ/mol
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A 45g Aluminum spoon (specific heat 0.88J/g degree Celcius) at 24 degrees Celcius placed in 180ml(180g) of coffee at 85 degrees Celcius and the temperature of the two become equal. What is the final temperature?
Answer:
82 °C
Explanation:
Let the specific heat capacity of the coffee be that of water which is 4.2 J/g °C.
Now, at the final temperature, heat gained by Aluminum spoon ,Q equals heat lost by coffee, Q'.
Q = -Q'
Q = m₁c₁(T₂ - T₁) where m₁ = mass of aluminum spoon = 45 g, c₁ = specific heat of aluminum = 0.88 J/g °C, T₁ = initial temperature of aluminum spoon = 24 °C and T₂ = final temperature of aluminum spoon.
Q' = m₂c₂(T₂ - T₃) where m₂ = mass of coffee = 180 g, c₂ = specific heat of coffee = 4.2 J/g °C, T₃ = initial temperature of coffee = 85 °C and T₂ = final temperature of coffee.
So, Q = -Q'
m₁c₁(T₂ - T₁) = -m₂c₂(T₂ - T₃)
Making T₂ subject of the formula, we have
m₁c₁T₂ - m₁c₁T₁ = -m₂c₂T₂ + m₂c₂T₃
m₁c₁T₂ + m₂c₂T₂ = m₂c₂T₃ + m₁c₁T₁
(m₁c₁ + m₂c₂)T₂ = m₂c₂T₃ + m₁c₁T₁
T₂ = (m₂c₂T₃ + m₁c₁T₁)/(m₁c₁ + m₂c₂)
substituting the values of the variables into the equation, we have
T₂ = (180 g × 4.2 J/g °C × 85 °C + 45 g × 0.88 J/g °C × 24 °C )/(45 g × 0.88 J/g °C + 180 g × 4.2 J/g °C)
T₂ = (64260 J + 950.4 J)/(39.6 J/°C + 756 J/°C)
T₂ = 65210.4 J/795.6 J/°C
T₂ = 81.96 °C
T₂ ≅ 82 °C
How many moles of Cd and of N are contained in 132.4 g of Cd(N03)2-4H20? (b) How many molecules of water of hydration are in this same amount?
Answer: The given amount of [tex]Cd(NO_3)_2.4H_2O[/tex] contains 0.430 moles of Cd, 0.860 moles of N and [tex]2.59\times 10^{23}[/tex] molecules of water.
Explanation:
The number of moles is defined as the ratio of the mass of a substance to its molar mass. The equation used is:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] ......(1)
Given mass of [tex]Cd(NO_3)_2.4H_2O[/tex] = 132.4 g
Molar mass of [tex]Cd(NO_3)_2.4H_2O[/tex] = 308.5 g/mol
Plugging values in equation 1:
[tex]\text{Moles of }Cd(NO_3)_2.4H_2O=\frac{132.4g}{308.5g/mol}=0.430 mol[/tex]
1 mole of [tex]Cd(NO_3)_2.4H_2O[/tex] contains 1 mole of Cd, 2 moles of nitrogen atom (N), 10 moles of oxygen atom (O) and 8 moles of hydrogen atom (H).
So, 0.430 moles of [tex]Cd(NO_3)_2.4H_2O[/tex] will contain = [tex](1\times 0.430) = 0.430mol[/tex] of Cd and [tex](2\times 0.430)=0.86mol[/tex] of N
According to the mole concept:
1 mole of a compound contains [tex]6.022\times 10^{23}[/tex] number of molecules
So, 0.430 moles of [tex]Cd(NO_3)_2.4H_2O[/tex] will contain = [tex]\frac{6.022\times 10^{23}}{1mol}\times 0.430mol=2.59\times 10^{23}[/tex] number of water molecules.
Hence, the given amount of [tex]Cd(NO_3)_2.4H_2O[/tex] contains 0.430 moles of Cd, 0.860 moles of N and [tex]2.59\times 10^{23}[/tex] molecules of water.
0.2g of water represents how many mole?
Answer:
0.0111moles
Explanation:
as moles = mass/ mr(16+1+1)
so 0.2g / 18
gives you 0.111moles
hope this helps :)
Which statement best describes how forces are important to chemistry?
A. Forces are transferred when atoms form ions.
B. Forces are released during chemical reactions.
C. Forces determine the extent of a reaction.
D. Forces hold atoms and molecules together.
Answer:
D
Explanation:
Which of the following pairs of elements will form ionic bonds with each
other?
A. Silver (Ag) and silver (Ag)
B. Lithium (Li) and iodine (1)
C. Bromine (Br) and bromine (Br)
D. Carbon (C) and chlorine (CI)
Answer:
B. Lithium (Li) and iodine (1)
Explanation:
Ionic bond is a type of chemical bond that is formed between a metallic element and a non metallic element. The positive charge of the metallic ion is attracted to the negative charge of the non metallic ion to form an ionic bond.
According to the options given in this question, lithium and iodine will form an IONIC bond because lithium is a cation (+ve ion) while iodine is an anion (-ve).
list from soft to hard
List the following minerals in order from softest to hardest:
apatite, calcite, talc, quartz, diamond.
PLZ HELP ME WITH MY WORK
Answer:
Explanation:
pretty sure its mixure.
calculate the maximum mass of ethanol that could be obtained from 30.0g of glucose
Answer:
15.3g
Explanation:
C6H12O6 → 2C2H5OH + 2CO2
1 mol C6H12O6 = 180g
1 mol CH3-CH2-OH = 46g
From 180g glucose ethanol can get = 92g
30g glucose ethanol gives us = (92*30)/180 = 15.33g
is (H) a positive or negative value
Answer:
A chemical reaction that has a positive ΔH is said to be endothermic , while a chemical reaction that has a negative ΔH is said to be exothermic . What does it mean if the ΔH of a process is positive? It means that the system in which the chemical reaction is occurring is gaining energy.
PLZ HELP Question 14 of 25 What is the name for a representation of the physical world?
A. Model
B. Compound
C. Atom
D. Alloy SUBMIN
Answer:
Model
Explanation:
A model of anything is something you make to represent it in it's physical world form
A chemist sets up a chemical reaction but finds that none of the reactant molecules have the required activation energy. What is the result?
A.
Products will form with less energy input.
B.
No products will be formed.
C.
The products will form too quickly.
D.
Products will convert to reactants.
Answer:
B.
No products will be formed.
A newspaper story describing the local celebration of Mole Day on October 23 (selected for Avogadro's number, 6.02 X 10^ 23 ) attempting to give the reader a sense of the size of the number by stating that a mole of M&Ms would be equal to 18 tractor trailers full. Assuming that an M&M occupies the volume of about 0.5 cm ^ 3 calculate the dimensions of a cube required to hold one mole of M&Ms. Would 18 tractor trailers be sufficient?
Answer:
The answer is "670.176 km".
Explanation:
Volume of the occupies of one M & M= 0.5 \ cm^3\\\\
M&M 1 mole[tex]= 6.02 \times 10^{23}\\\\[/tex]
Calculating volume of M& M mole[tex]= 0.5 \ cm^3 \times 6.02 \times 10^{23}=3.01 \times 10^{23}\ cm^3\\\\[/tex]
Calculating the cube mole[tex]L^3= 3.01 \times 10^{23}\ cm^3\\\\[/tex]
[tex]L=6.70176 \times 10^{7}\ cm\\\\[/tex]
[tex]=6.70176 \times 10^{7}\ cm \times \frac{1\ m}{100\ cm}\\\\=670176\ m\\\\=670.176 \ km[/tex]
Therefore 18 tractor trailers wouldn't be sufficient.
solubility of salt at 10 degree Celsius is 20 how does it what does it means what happens if the temperature of saturated solution is increased and decreased explain it in detail
Answer:
solubility of salt at 10 degree Celsius is 20 how does it what does it means what happens if the temperature of saturated solution is increased
Explanation:
solubility of salt at 10 degree Celsius is 20 how does it what does it means what happens if the temperature of saturated solution is increased
When a compound is added to water only a few of its molecules dissociate to produce hydrogen ions. It is a...
a. strong acid.
b. weak acid.
c. strong base.
d. weak base.
At what approximate temperature and pressure can all three phases of water exist simultaneously?
0°C, 760 mmHg
0°C, 5 mmHg
80°C, 380 mmHg
100°C, 760 mmHg
Answer:
0⁰c , 5 mmHg
Explanation:
Because at this temperature we all know water can be in state of both solid and liquid and when pressure is decreased it can be in form of gas too
Suggest a way that a scientist could create an even more accurate model of universe expansion
Answer:
Between galaxies, retake the measurement.
Explanation:
Among both galaxies, reiterate the measurements. Instead of utilising a balloon, a scientist might create a model that shows in which everything really is and how cosmos is expanding rather than expanding. By inflating up the atmosphere to 1/2, 3/4, and full size, continue the operation.
name some examples of chemical solutions and maybe give a clear explanation as to what chemical solutions are
Answer:
Some examples of solutions are salt water, rubbing alcohol, and sugar dissolved in water. ... In our example of salt water, the solute is the salt. Solvent: this is the substance that makes up the majority of the solution. This is the part where the solute is dissolved.
Explanation:
I hope they should be right answer
Can Some One Please Help Me
Answer:
12 g
Explanation:
From the question given above, the following data were:
Number of atoms = 6.02×10²³ atoms
Mass of ₆C¹² =?
From Avogadro's hypothesis,
1 mole of any substance contains 6.02×10²³ atoms. This implies that 1 mole of ₆C¹² also contains 6.02×10²³ atoms i.e
1 mole of ₆C¹² = 6.02×10²³ atoms
Recall
From the period,
1 mole of ₆C¹² = 12 g
Thus,
12 g of ₆C¹² = 6.02×10²³ atoms
Therefore, 12 g of ₆C¹² contains 6.02×10²³ atoms
Tenemos una disolución de HNO3 cuya pureza es del 65% y tiene una densidad de 1.32 g/mL. ¿Cuál es la molaridad de la disolución? PM HNO3 = 63.0 g/mol.
Teniendo en cuenta que la molaridad es el número de moles de soluto que están disueltos en un determinado volumen, la molaridad de la disolución de HNO₃ es 14.67 [tex]\frac{mol}{L}[/tex].
El porcentaje en masa o en peso de una disolución es el número de gramos de soluto que hay por cada 100 gramos de disolución.
Entonces una pureza de 65% indica que hay 70 g de HNO₃ puro por cada 100 g de HNO₃ impuro.
Por otro lado, la densidad es la relación entre el peso o masa de una sustancia y el volumen que ocupa esa misma sustancia.
Entonces, si la disolución de HNO₃ tiene una densidad de 1.32 g/mL (equivalente a 1320 g/L), donde la cantidad de masa es impura, se puede obtener la cantidad de masa de HNO₃ presente 1 L de la solución mediante el siguiente cálculo:
[tex]\frac{1320 g HNO_{3} impuro}{1 L}x \frac{70 g HNO_{3}puro}{100 g HNO_{3}impuro}= 924 \frac{g HNO_{3}puro}{L}[/tex]
Finalmente, la masa molar de HNO₃, es decir la masa presente en un mol de la sustancia, es 63 [tex]\frac{g}{mol}[/tex].
Entonces, teniendo en cuenta que la molaridad es el número de moles de soluto que están disueltos en un determinado volumen, es posible determinar la molaridad como:
[tex]\frac{924 g HNO_{3}puro}{L}* \frac{1 mol}{63 g}= 14.67 \frac{mol}{L}[/tex]
En resumen, la molaridad de la disolución es 14.67 [tex]\frac{mol}{L}[/tex]
Aprende más sobre la molaridad:
https://brainly.com/question/17647411?referrer=searchResultshttps://brainly.com/question/21276846?referrer=searchResultsWhat is the pH value of lithium chloride?
Answer:
0.0003HERE IS YOUR ANSWERQUICK PLEASE!!!
Argon is an element in the last column of the periodic table. What is its highest energy sublevel?
A.D
OB.
OC.P
DS
The highest energy sublevel of argon will be p.
ArgonArgon has an atomic number of 18.
Thus, the electron configuration of argon will be [tex]1s^2, 2 s^2, 2 p^6, 3 s^2, 3 p^6[/tex]
The ascending order of energy for the sublevel orbitals is s, p, d, and f.
Therefore, the highest energy sublevel of argon is p.
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The highest energy sublevel in the element argon is p.
What is the periodic table?The periodic table is an arrangement of atoms according to their order of increasing atomic numbers. Now we know that there are 18 groups in the periodic table and argon belongs to group 18.
The electron configuration of argon is; 1s2 2s2 2p6 3s2 3p6. Thus, the highest energy sublevel in the element argon is p.
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A compound was found to contain 90.6% lead (Pb) and 9.4% oxygen. What is the empirical formula for this compound?
Answer:
the answer is 47.9 and ik because I just had that question
The empirical formula of the compound is O₄Pb₃.
What is the empirical formula?
An Empirical system is the chemical system of a compound that offers the proportions of the elements gifted within the compound however not the real numbers or arrangement of atoms. This would be the lowest complete variety ratio of the elements within the compound.
Amount of lead (Pb) = 90.6%
⇒and amount of oxygen = 9.4%
taking the whole number ratio
o = 4
Pb = 3
∴ ⇒O: Pb=4:3
O4Pb3 answer.
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what are the defects of mendeleev's periodic table
Answer:
1 Anomalous Pairs. The rest of the pairs of elements don't follow the follow Mendeleev's Principles . they are :
2Grouping of chemically dissimilar elements.
3Position of Isotopes.
4Electronic arrangement.
5Separation of chemically similar elements.
6The position of hydrogen.
En una carrera de atletismo un deportista se muestra agotado sin fuerzas para continuar y decide abandonar la carrera ¿Que alimentos tomo antes de la carrera ?
Answer:
Los alimentos para evitar la fatiga durante una carrera son alimentos bajos en grasas y altos en carbohidratos, así como alimentos bajos en fibra como pan, mantequilla de maní, plátano, jugo de frutas sin pulpa, y beber hasta aproximadamente 600 ml de líquido aproximadamente 3 horas. antes de la carrera
La comida para comer unos días antes de la carrera incluye carnes magras, arroz, pasta y verduras con contenido de almidón.
Los alimentos que se deben evitar incluyen carne roja, alimentos con alto contenido de grasas saturadas, alimentos fritos, pasteles y salchichas.
Explanation:
What is Spontaneous ion
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