Name two types of silk
Answer:
Tussar silk
Charmeuse
Explanation:
Hope this helps! :)
A gas has a volume of 1000.0 mL at a temperature of 20.OK and a pressure
of 1.0 atm. What will be the new volume when the temperature is changed
to 40.0K and the pressure is changed to
0.5 atm?
Answer:
4000mL
Explanation:
Using the combined gas law equation as follows:
P1V1/T1 = P2V2/T2
Where;
P1 = initial pressure (atm)
P2 = final pressure (atm)
V1 = initial volume (mL)
V2 = final volume (mL)
T1 = initial temperature (K)
T2 = final temperature (K)
According to the information given in this question:
V1 = 1000mL
T1 = 20K
P1 = 1.0atm
V2 = ?
P2 = 0.5atm
T2 = 40K
Using P1V1/T1 = P2V2/T2
1 × 1000/20 = 0.5 × V2/40
1000/20 = 0.5V2/40
50 = 0.5V2/40
50 × 40 = 0.5V2
2000 = 0.5V2
V2 = 2000/0.5
V2 = 4000mL
What does a particular point on a line of a phase diagram represent?
A. The melting point or boiling point of a substance at a specific
pressure
B. The maximum temperature a substance can exist at without
bonds breaking
C. The pressure created by the kinetic energy of molecules at a
particular temperature
D. The conditions in which temperature and pressure have equal
effects on a substance
Answer: A
Explanation:
the melting point or boiling point of a substance at a specific pressure
Which of these is correct?
Answer:
1.89 nol Cu(NO3)2
Explanation:
if you calculate it it will be 1.89
Question 1 of 30
Why does atomic size increase as you go down a group on the periodic table?
A. Because the number of electron shells increases
B. Because there is more total attraction between electrons in the
shells and protons in the nucleus
C. Because the number of electron shells decreases
D. Because there is less total attraction between electrons in the
shells and protons in the nucleus
SUBMI
Answer:
Explanation:
Down a group, the number of energy levels (n) increases, so there is a greater distance between the nucleus and the outermost orbital. This results in a larger atomic radius.
PLEASE HELP
If 62.6 g of lead (II) chloride is produced, how many grams of lead (II) nitrate were reacted?
Answer: The mass of lead (II) nitrate required is 74.52 g
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 lead (II) chloride = 62.6 g
Molar mass of lead (II) chloride = 278.1 g/mol
Plugging values in equation 1:
[tex]\text{Moles of lead (II) chloride}=\frac{62.6g}{278.1g/mol}=0.225 mol[/tex]
The chemical equation for the reaction of lead (II) chloride and sodium nitrate follows:
[tex]Pb(NO_3)_2+2NaCl\rightarrow PbCl_2+2NaNO_3[/tex]
By the stoichiometry of the reaction:
1 mole of lead (II) chloride is produced from 1 mole of lead (II) nitrate
Then, 0.225 moles of lead (II) chloride will react with = [tex]\frac{1}{1}\times 0.225=0.225mol[/tex] of lead(II) nitrate
Molar mass of lead (II) nitrate = 331.2 g/mol
Plugging values in equation 1:
[tex]\text{Mass of lead (II) nitrate}=(0.225mol\times 331.2g/mol)=74.52g[/tex]
Hence, the mass of lead (II) nitrate required is 74.52 g
write the application of thermodynamic
Answer:
One of the most important things we can do with heat is to use it to do work for us. A heat engine does exactly this—it makes use of the properties of thermodynamics to transform heat into work. Gasoline and diesel engines, jet engines, and steam turbines that generate electricity are all examples of heat engines.
1. BaBr2(aq) + H2SO4(aq) →?
please balance the equation and predict the products
Answer:
BaBr2 (aq) + H2SO4 (aq) → BaSO4 (s) + 2 HBr (aq)
Explanation:
This is a precipitation reaction: BaSO4 is the formed precipitate.
An electron in a hydrogen atom moves from level 1 to level 4. The electron then drops from level 4 to level 2. Which
statement describes the most likely result?
O The energy absorbed in the first move equals the energy released in the second move.
O The energy absorbed in the first move is greater than the energy released in the second move.
O The energy released in the first move equals the energy absorbed in the second move.
O The energy released in the first move is greater than the energy absorbed in the second move.
Answer:
The energy absorbed in the first move is greater than the energy released in the second move
Explanation:
Electrons require (absorb) energy to move to a higher energy level when there is a large external heat source, the presence of an electric field or by colliding with other electrons
And the amount of energy absorbed by the electron is exactly equal to the change in the energy state between the initial energy level of the electron and the destination energy level
Therefore, given that the energy level of the electron at level 2 is higher than the energy level of the electron when at level 1, we have;
The difference in the energy level between level 4 and level 1 is greater than the difference in the energy level between level 4 and level 2 and more energy is absorbed and therefore, released when the electron moves from level 1 to level 4 than when the electron drops from level 4 to level 2.
The most likely result is that 'the energy absorbed in the first move is greater than the energy released in the second move'.
what is neutralisation reaction? why is it named so? give one example.
Answer:
In chemistry, neutralization or neutralisation is a chemical reaction in which acid and a base react quantitatively with each other. In a reaction in water, neutralization results in there being no excess of hydrogen or hydroxide ions present in the solution.Neutralization reactions are the reaction between acid and base. The products formed are water and salt. It is called so because the acid and base neutralize each other to form water and salt.Hint: The neutralization reaction is the one in which an acid reacts with an equimolar amount of base to give salt and water. The example could be a reaction between any strong acid and a base. The sodium chloride formed is a result of neutralization reaction.
Trust me mark me as brainliest trust me
why metals should not be disposed in landfills
Answer:
Because metal can not decompose!
SE LES DARA EL NUMERO ATOMICO DEBERAN REALIZAR LA CONFIGURACION ELECTRONICA ESCRIBE SU NOMBRE SIMBOLO Y UBICACION EN LA TABLA PERIODICA Z- 30,58,81,17,36
Answer:
Zinc, Cerio, Talio, Cloro y Criptón.
Explicación:
El zinc es el elemento que tiene el número atómico 30 y su símbolo es Zn. Se encuentra en el grupo 2B de la tabla periódica. El cerio es el elemento que tiene el número atómico 58 y su símbolo es Ce. Se encuentra en el grupo de lantánidos de la tabla periódica. El talio es el elemento que tiene el número atómico 81 y su símbolo es Tl. Se encuentra en el tercer grupo de la tabla periódica. El cloro es el elemento que tiene el número atómico 17 y su símbolo es Cl. Se encuentra en el séptimo grupo de la tabla periódica. El criptón es el elemento que tiene el número atómico 36 y su símbolo es Kr. Se encuentra en el grupo de gases nobles, es decir, en la tabla periódica del octavo grupo.
On a graph showing distance versus time, a horizontal line represents an object that is
moving at a constant speed.
increasing its speed.
decreasing its speed.
not moving at all.
Answer:
the anwser is; B: increasing its speed
3KOH + FeCl3 → Fe(OH)3 + 3KCl
How many grams of KCl are produced when 12.5 moles of KOH completely react with excess of FeCl3?
Answer:
sry, dk
Explanation:
A student is provided with a sample of iron pyrite and a sample of gold. Suggest how the student could distinguish between the two substances
Answer:
Gold and pyrite both have a brilliant metallic luster, but are different tones of yellow. Gold is golden to silvery yellow, whereas pyrite is a pale to medium brassy yellow that sometimes tarnishes.
Explanation:
Atoms are attracted to each other because____
A) electrons are attracted to protons because they have opposite charges
B) magnets pull them together
C) the protons are attracted to each other because they have the same charge
D) they have some energy
SOMEONE PLEASE HELP:/!
Answer:
A
Explanation:
Opposite charges attract therefore the electrons of one atom would be attracted by the nucleus (which contains protons). This heavily relies on a property called electronegativity. Which deals with the level of attraction a nucleus (the protons in the nucleus) have for electrons of other atoms.
What happens to the freezing point of a solution when more solute is added?
Cells can regulate different processes in two ways. They can turn on and off the genes that make enzymes, or they can
A)
increase the activation energy of a reaction.
B)
increase the amount of energy needed to carry out the preferred process.
C)
regulate the enzymes that are already made.
D)
decrease the amount of energy needed to carry out the preferred process.
sodium reacts with chlorine gas to form sodium chloride. if you have 60 L of chlorine gas at STP and 30 g of sodium, how many grams of salt would be formed? i know the answer is 75 grams but i need to show my work and i don't know what to write for the equation
Answer:
75.9 grams of salt
Explanation:
The reaction is the following:
2Na(s) + Cl₂(g) → 2NaCl(s) (1)
We have:
m(Na): the mass of sodium = 30 g
V(Cl₂): the volume of the chlorine gas at STP = 60 L
So, to find the mass of NaCl we need to calculate the number of moles of Na and Cl₂.
[tex] n_{Na} = \frac{m}{A_{r}} = \frac{30 g}{22.99 g/mol} = 1.30 moles [/tex]
The number of moles of Cl₂ can be found by the Ideal gas law equation:
[tex] PV = n_{Cl_{2}}RT [/tex]
Where:
P: is the pressure = 1 atm (at STP)
R: is the gas constant = 0.082 L*atm/(K*mol)
T: is the temperature = 273 K (at STP)
[tex] n_{Cl_{2}} = \frac{PV}{RT} = \frac{1 atm*60 L}{0.082 L*atm/(K*mol)*273 K} = 2.68 moles [/tex]
Now we need to find the limiting reactant. From the stoichiometric relation between Na and Cl₂ (equation 1), we have that 2 moles of Na react with 1 mol of Cl₂, so:
[tex] n_{Na} = \frac{2 moles Na}{1 mol Cl_{2}}*2.68 moles Cl_{2} = 5.36 moles [/tex]
Since we have 1.30 moles of Na, the limiting reactant is Na.
Finally, we can find the number of moles of NaCl and its mass.
[tex] n_{NaCl} = n_{Na} = 1.30 moles [/tex]
[tex] m_{NaCl} = n_{NaCl}*M = 1.30 moles*58.44 g/mol = 75.9 g [/tex]
Therefore, would be formed 75.9 grams of salt.
I hope it helps you!
Which atom attracts electrons most strongly? br F Rb
Fluorine has the highest electronegativity in comparison to other elements therefore, the F atom attracts electrons most strongly.
What is electronegativity?The electronegativity of an atom measures the tendency of an element to attract the bonded electrons pairs towards itself. The electronegativity of an atom is determined with respect to another bonded atom.
Electronegativity can be described as a chemical property of an atom or a functional group to attract electrons toward itself. The electronegativity of an atom depends on the atomic number and the distance of valence electrons from the charged nuclei.
When two different atoms are bonded through a bond. More electronegative will attract the electron density of the bond towards itself.
As we know, the electronegativity decreases as we move down the group in the periodic table. Fluorine is the most electronegative element in the periodic table therefore, Fluorine (F) will attract the electrons toward it most strongly.
Learn more about electronegativity, here:
brainly.com/question/17762711
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How do you find the number of moles of copper in copper gluconate? In my experiment I used 1.4 g of copper gluconate, and ended up with 0.1 g of copper.
Answer: 0.0016 moles of copper are present in copper gluconate
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 copper = 0.1 g
Molar mass of copper = 63.55 g/mol
Plugging values in equation 1:
[tex]\text{Moles of copper}=\frac{0.1g}{63.55g/mol}=0.0016 mol[/tex]
Hence, 0.0016 moles of copper are present in copper gluconate
WHAT IS A SAFE WAY TO BAKE SODA IN THE OVEN WITHOUT IT SPEWING EVERYWHERE?
put the glass lid on and turn or turn down the heat
According to this balanced equation, how many grams of water (H.0) form in
this reaction?
Beo
2HCI
+
BeCl2
79.919
Н,0
?
25.019
72.919
A. 177.84 grams
B. 127.82 grams
C. 32.00 grams
O D. 18.02 grams
Answer:
your simpal answer is 177.32
Help quick, please!
which two terms are related to the energy you get by eating an apple?
chemical
kinetic
gravitational
potential
Please pick two of these!
Answer:
potential and chemical
Explanation:
can u pls answer 22, 23, 24
Answer:
I'm terribly sorry but the download is not working for me! All it says is Download pdf, and when I click it, It does nothing except for refreshing the page!
Explanation:
The expression for the equilibrium constant for the reaction:
Ba3N2 (aq) + 6 H2O(1)-
3 Ba(OH)2 (aq) + 2 NH3 (9)
Answer:
[tex]Kc\frac{(Ba3N2)(H2O)^6}{(Ba(OH)2)^3(NH3)^2}[/tex]
Explanation:
Because kc equals products/reactants hope this helps :)
PLSSSS HELP WILL GIVE BRAINLIEST!!!!!!!!!
Answer:
72.2 moles of water is spilled
Explanation:
as moles=mass/mr
so mr of water is 16+2=18
13000/18=72.2
for the second one you can work out the moles of o2
by using moles= number of particles /6.02*10^23
so 4.65*10^26/6.02*10^23
so i got 772.4 on my calculator to work out the amount of mass
u use the equation mass=moles*mr
so 777.2*16=12435g of oxygen gas
hope it helps :)
Answer:
ask someone else I will help later
Use the reaction N2(g) + 3H2(g) 2NH3(g) to answer the following questions
a. 1 pt: What does Le Châtelier's principle predict would happen to the equilibrium conditions if N2(g) + 3H2(g) were added to the system?
b. 1 pt: What would happen to the equilibrium if the pressure were decreased?
c. 2 pts: Write the equation for calculating Keq
d. 3 pts: Calculate the value for Keq given the following concentrations
[NH3] = 6 M
[H2] = 4 M
[N2] = 3 M
Answer:
Explanation:
a ) If N₂(g) and 3H₂(g) is added to the system , 2 moles of additional ammonia will be produced .
b ) If pressure is decreased , less amount of ammonia will be formed, because forward reaction reduces the pressure. So, reaction will take place in reverse direction.
c ) Keq = [ NH₃ ] ² / [ N₂ ] [ H₂]³
d ) Substituting the given values in the equation ,
Keq = [ 6M ] ² / [ 3M] [ 4M]³
= 36 / 3 x 64 M⁻²
= 18.75 x 10⁻² M⁻² .
¿Qué tipos de contaminantes identificamos?¿cuál de ellos tiene mayor concentración de los gases?¿Qué sucedió con la calidad del aire en el inicio de la pandemia? Y como va en la esta última semana de la pandemia?
Answer:
Bueno al principio pero empeorando con el paso del tiempo.
Explicación:
La calidad del aire es buena al inicio de la pandemia y hay menos infección en el aire pero con el paso del tiempo la infección se propaga a un ritmo más rápido y la calidad del aire se contamina con la infección que infecta a más personas. La pandemia reduce su intensidad cuando la gente sigue las reglas saludables que previenen la propagación de la pandemia en esa localidad por lo que podemos decir que la última semana de pandemia tiene menor número de pacientes.
which method would be best for separating the compounds of a mixture that is made from two diffrent liquids
Answer:
fractional distillation since ot depends on the different liquids to have different boiling points