Answer:
PIEASE E first write question
a sample of gas measures 5 liters at 1 atm. to change the volume to a 3.5 liters at constant temperature what pressure must be applied
Answer:
0.7atm
Explanation:
3.5/5 because constant temperature
How much energy is needed to heat enough water to make a cup of tea (250 ml), if the water is initially at 20.0°C and you want to increase the temperature to 85.0°C? (1.00 mL of water has a mass of 1.00 g.)
As the tea in the previous question steeps, it cools from 85.0°C to 75.0°C. How much energy is lost by the tea as it steeps?
Answer:
Heat Energy needed (Q) = 68250 J
Energy lost (Q') = 10500 J
Explanation:
Applying,
Q = cm(t₂-t₁)............. Equation 1
Where Q = heat energy needed, c = specific heat capacity of water, m = mass of water, t₁ = initial temperature, t₂ = final temperature.
From the question,
Given: m = 250 g = 0.25 kg, t₁ = 20.0°C, t₂ = 85.0°C
Constant: c = 4200 J/kg°C
Substitute these values into equation 1
Q = 0.25(4200)(85-20)
Q = 68250 J.
Similarly, heat lost
Q' = cm(t₁-t₂)................. Equation 2
Where Q = heat lost
Given: t₁ = 85°C, t₂ = 75°C
Substitute into equation 2
Q' = 4200(0.25)(85-75)
Q' = 10500 J
PLEASE HELP THIS IS AN EMERGENCY!!!!
A template of a Venn diagram representing common and differentiating characteristics of covalent and ionic bonds is shown.
Which of the following characteristics can be written only in space A? (5 points)
A.)Formed between atoms of similar electronegativities
B.)Formed between two metal atoms mostly found on the left of the periodic table
C.)Formed between two non-metal atoms mostly found on the right of the periodic table
D.)Formed between an atom that tends to lose electrons and an atom that tends to gain electrons
Answer:
D
Explanation:
Ionic bonds form when a metal and a nonmetal exchange electrons.
A) atoms with relatively similar electronegativities share electrons between them and form covalent bonds
B) the force that holds atoms together in a metallic substance is known as a metallic bond. such a solid consists of closely packed atoms....in short, the valence electrons in metals, unlike those of covalent bonds, are nonlocalized and capable of wandering relatively freely throughout the entire molecule
C) bonds formed between two nonmetals are mainly covalent bonds
.The characteristic that can be written in A only is that ionic bonds are "formed between an atom that tends to lose electrons and an atom that tends to gain electrons" option D.
Ionic bondIonic or electrovalent bonds are bonds formed between oppositely charged ions which are formed by a gain or loss of electrons and these ions are held together by strong electrostatic forces of attraction.
Properties of Ionic bondsThey are formed between oppositely charged ions ionsThey occur as a result of electrostatic forces of attraction between oppositely charged ions They are formed between an atom that tends to lose electrons {usually metals} and an atom that tends to gain electrons {usually non-metals}.Therefore, characteristic that can be written in A only is that ionic bonds are "formed between an atom that tends to lose electrons and an atom that tends to gain electrons" option D.
Learn more about ionic bonds at: https://brainly.com/question/13526463
when water is added pH of the acidic solution
1 remain same
2 increases
3 decrease s
4 become zero
Answer:
the solution becomes less concentrated... meaning there is a decrease in acidity ...hence the pH slightly increases as lesser ph
means more acidity
17) A 0.20 M solution of HCl with a volume of 15.0 mL is exactly neutralized by the 0.10 M solution of NaOH with what volume? HINT: Use the titration formula from table T. First multiply, then divide. o 1.5 mL O 7.5 mL 7 o 3.0 mL 0 30. mL
Answer: A 0.20 M solution of HCl with a volume of 15.0 mL is exactly neutralized by the 0.10 M solution of NaOH with 3 mL volume.
Explanation:
Given: [tex]M_{1}[/tex] = 0.20 M, [tex]V_{1}[/tex] = 15.0 mL
[tex]M_{2}[/tex] = 0.10 M, [tex]V_{2}[/tex] = ?
Formula used is as follows.
[tex]M_{1}V_{1} = M_{2}V_{2}[/tex]
Substitute the values into above formula s follows.
[tex]M_{1}V_{1} = M_{2}V_{2}\\0.20 M ]times 15.0 mL = 0.10 M ]times V_{2}\\V_{2} = 30 mL[/tex]
Thus, we can conclude that a 0.20 M solution of HCl with a volume of 15.0 mL is exactly neutralized by the 0.10 M solution of NaOH with 3 mL volume.
The nth shell holds a minimum number of 2n2 electrons
True
False
Other:
Answer: The statement the [tex]n^{th}[/tex] shell holds a minimum number of [tex]2n^{2}[/tex] electrons is true.
Explanation:
The alphabet 'n' denotes the principal quantum number whose value can be equal to 1, 2, 3, and so on but can never be zero.
Basically, 'n' is the number of shell of an atom and total number of orbitals present in a shell is [tex]n^{2}[/tex].
Each orbital can hold up to a maximum of wo electrons. Hence, the [tex]n^{th}[/tex] shell can hold a minimum number of [tex]2n^{2}[/tex] electrons.
Thus, we ca conclude that the statement the [tex]n^{th}[/tex] shell holds a minimum number of [tex]2n^{2}[/tex] electrons is true.
Obtener la fórmula empírica de un compuesto cuya composición centesimal reporta: Cr: 26,53 % , S: 24,52 % y O: 48,96%. Dato: m.A. [Cr= 52 , S= 32]
Respuesta:
Cr₂S₃O₁₂
Explicación:
Primer paso: Dividir el porcentaje en masa de cada elemento por su masa atómica
Cr: 26,53/52 = 0,510
S: 24,52/32 = 0,766
O: 48,96/16 = 3,06
Segundo paso: Dividir todos los números por el más pequeño (0,510)
Cr: 0,510/0,510 = 1
S: 0,766/0,510 = 1,5
O: 3,06/0,510 = 6
Tercer paso: Multiplicar todos los números por algún número que haga que todos sean enteros (2)
Cr: 1 × 2 = 2
S: 1,5 × 2 = 3
O: 6 × 2 = 12
La fórmula empírica es Cr₂S₃O₁₂.
Answer: The empirical formula of the compound becomes [tex]Cr_2S_3O_{12}[/tex]
Explanation:
The empirical formula is the chemical formula of the simplest ratio of the number of atoms of each element present in a compound.
Let the mass of the compound be 100 g
Given values:
% of Cr = 26.53%
% of S = 24.52%
% of O = 48.96%
Mass of Cr = 26.53 g
Mass of S = 24.52 g
Mass of O = 48.96 g
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)
To formulate the empirical formula, we need to follow some steps:
Step 1: Converting the given masses into moles.Molar mass of Cr = 52 g/mol
Molar mass of S = 32 g/mol
Molar mass of O = 16 g/mol
Putting values in equation 1, we get:
[tex]\text{Moles of Cr}=\frac{26.53g}{52g/mol}=0.510 mol[/tex]
[tex]\text{Moles of S}=\frac{24.52g}{32g/mol}=0.766 mol[/tex]
[tex]\text{Moles of O}=\frac{48.96g}{16g/mol}=3.06 mol[/tex]
Step 2: Calculating the mole ratio of the given elements.Calculating the mole fraction of each element by dividing the calculated moles by the least calculated number of moles that is 0.510 moles
[tex]\text{Mole fraction of Cr}=\frac{0.510}{0.510}=1[/tex]
[tex]\text{Mole fraction of S}=\frac{0.766}{0.510}=1.5[/tex]
[tex]\text{Mole fraction of O}=\frac{3.06}{0.510}=6[/tex]
Multiplying the mole fraction of all the elements by 2, in order to make it as a whole number
[tex]\text{Mole fraction of Cr}=(2\times 1)=2[/tex]
[tex]\text{Mole fraction of S}=(2\times 1.5)=3[/tex]
[tex]\text{Mole fraction of O}=(2\times 6)=12[/tex]
Step 3: Taking the mole ratio as their subscripts.The ratio of Cr : S : O = 2 : 3 : 12
Hence, the empirical formula of the compound becomes [tex]Cr_2S_3O_{12}[/tex]
¿A qué se refiere cuando se dice que el trabajo científico es cualitativo y cuantitativo? Por favor
Answer:
ver explicacion
Explanation:
La investigación cualitativa tiene que ver con la investigación que implica la recopilación de datos no numéricos, mientras que la investigación cuantitativa tiene que ver con la recopilación de datos numéricos.
La investigación científica a menudo tiene que ver con la observación y la realización de inferencias. Este aspecto de la investigación científica es cualitativo.
Al mismo tiempo, es posible que también se requieran gráficos, tablas y cuadros para la presentación de datos en ciertos tipos de investigación científica. Esta es ahora una investigación cuantitativa.
Por tanto, la investigación científica es tanto cualitativa como cuantitativa
A student is performing an experiment that requires measuring the boiling point of water. The accepted
value for the boiling point of pure water is 100.0°C. In the experiment, the student measured the boiling
point to be 99.2°C. What is the percent error in the student's experiment?
Answer:
.8°c my fingers jfjfjkfkrhrb
One mole of Beryllium weighs 9.0122 grams. How many atoms of Beryllium are
there?
4
9.0122
6.022 x 10^23
18
Answer:
4
Explanation:
cause 1 mole of beryllium weighs 4gram
state and explain the trends in the atomic radius and ionization energy for elements Li to Cs.
Explanation:
ionisation energy decrease down the group as the atomic radius increases. Nuclear charge increases. Number of shell increases so the electron will experience more shielding so it would be easier for the atom to loss electron.
The most outer solid portion of
the planet Earth
Answer:
The lithosphere is the most outer solid portion of
he most outer solid portion ofthe planet Earth.
crust is the outermost layer of earth.
Please select the word from the list that best fits the definition
Occurs when an axon releases chemicals that allow a signal to jump across synapses between neurons
Answer:
When a nerve impulse reaches the end of an axon, the axon releases chemicals called neurotransmitters. Neurotransmitters travel across the synapse between the axon and the dendrite of the next neuron. Neurotransmitters bind to the membrane of the dendrite.Explanation:
I hope it's helpful for you ☺️The values used in the scale of pH and pOH are derived from a system designed by ______.
Curie
Gordonsen
Dalton
Sorenson
A mixture of 0.5940 M CO and 0.3950 M Cl2 is enclosed in a vessel and heated to 1000 K . CO(g)+Cl2(g)↽−−⇀COCl2(g)c=255.0 at 1000 K Calculate the equilibrium concentration of each gas at 1000 K
Answer:
[CO] = 0.2064M
[Cl2] = 0.0074M
[COCl2] = 0.3876M
Explanation:
Based on the reaction, Kc at 1000K is:
Kc = 255.0 = [COCl2] / [CO] [Cl2]
Where [] are concentrations at equilibrium
As the reaction is 1:1, the concentrations at equilibrium are:
[CO] = 0.5940M - X
[Cl2] = 0.3950M - X
[COCl2] = X
Where X is reaction coordinate
Replacing:
255.0 = [X] / [0.5940 - X] [0.3950 - X]
255.0 = X / 0.23463 - 0.989 X + X²
59.8307 - 252.195 X + 255 X² = X
59.8307 - 253.195 X + 255 X² = 0
Solving for X:
X = 0.605M. False solution because produce negative answers
X = 0.3876M. Right solution.
Replacing:
[CO] = 0.5940M - 0.3876M
[Cl2] = 0.3950M - 0.3876M
[COCl2] = 0.3876M
[CO] = 0.2064M
[Cl2] = 0.0074M
[COCl2] = 0.3876M
The concentration at equilibrium of CO is 0.2064 M, [tex]\rm Cl_2[/tex] is 0.0074 M, and [tex]\rm COCl_2[/tex] is 0.3876 M.
The initial concentration of CO = 0.5940 M
[tex]\rm Cl_2[/tex] = 0.3950 M
At equilibrium,
Let the concentration of formed [tex]\rm COCl_2[/tex] = x
Concentration of CO = 0.5940 - x M
Concentration of [tex]\rm Cl_2[/tex] = 0.3950 - x M
[tex]\rm K_c[/tex] = 255
[tex]\rm K_c[/tex] = [tex]\rm \dfrac{[COCl_2]}{[CO]\;[Cl_2]}[/tex]
255 = [tex]\rm \dfrac{x}{[0.5940-x]\;[0.3950-x]}[/tex]
(151.47 - 255x) (100.727-255x) = x
15,256 - 65,025 [tex]\rm x^2[/tex] = x
0 = 65,025 [tex]\rm x^2[/tex] +x - 15,256
x = [tex]\rm\dfrac{-b\;\pm\;\sqrt{b^2\;-\;4ac} }{2a}[/tex]
a = 65,025
b = 1
c = -15,256
x = 0.38 M
Thus, the concentration at equilibrium of CO is 0.2064 M, [tex]\rm Cl_2[/tex] is 0.0074 M, and [tex]\rm COCl_2[/tex] is 0.3876 M.
For more information about the equilibrium concentration, refer to the link:
https://brainly.com/question/16645766
The student is now told that the four solids, in no particular order, are aluminum chloride (AlCl3AlCl3), sugar (C6H12O6C6H12O6), butanoic acid (C3H7COOHC3H7COOH), and potassium bromide (KBrKBr), and potassium bromide (KBr). Assuming that conductivity is correlated to the number of ions in solution, rank the four substances based on how well a 0.20 M solution in water will conduct electricity. Rank from most conductive to least conductive. To rank items as equivalent, overlap them.
Answer:
aluminum chloride> potassium bromide> butanoic acid> sugar
Explanation:
Conductivity has to do with the ability of a solid to dissolve in solution leading to the formation of mobile ions which are the charge carriers in solution.
Strong electrolytes produce more ions in solution hence they have a higher conductivity.
Aluminum chloride produces four particles in solution hence it has the highest conductivity followed by potassium bromide which produces two particles in solution. Butanoic acid is a weak electrolyte which dissociates only to a small extent while sugar is a nonelectrolyte, it does not dissociate at all in solution.
Why is sodium an active metal
Answer:
Sodium is very reactive in nature. When exposed in air, it automatically forms Na2O. When it is put in water it reacts vigorously and starts burning on water. Due to the above reasons Sodium is called an active metal
Explanation: hope this helps pls mark as brainliest ty
please show step by step and I will mark you as brainliest answer ❤️
Answer: The pH of the solution is 13.
Explanation:
pOH is defined as the negative logarithm of hydroxide ion concentration present in the solution.
[tex]pOH=-\log [OH^-][/tex]
We are given:
Concentration of [tex]Ca(OH)_2=0.05mol/dm^3=0.5mol/L[/tex] (Conversion factor: [tex]1L = 1dm^3[/tex] )
1 mole of calcium hydroxide produces 1 mole of calcium ions and 2 moles of hydroxide ions
Concentration of [tex]OH^-=(2\times 0.05)=0.1mol/L[/tex]
Putting values in above equation, we get:
[tex]pOH=-\log (0.1)\\\\pOH=1[/tex]
We know:
[tex]pH+pOH=14\\\\pH=14-1\\\\pH=13[/tex]
Hence, the pH of the solution is 13.
The absorption spectrum of sodium has a line at 589 nm. What is the energy of this line? (The speed of light in a vacuum is 3.00 x 10^8 m/s, and Planck's constant is 6.626 x 10^-34 Jos.)
A. 8.89 x 10^26 J
B. 5.09 x 10^14 J
C. 3.37 x 10^-19 J
D. 2.96 x 10^18 J
Answer:
C. 3.37 x 10^-19 J
Explanation:
Which compound is a hydrocarbon?
C 2 H 6
H 2 O
CO 2
C 6 H 12 O 6
Answer:
C2H6 OR C6H12O6 THE ANSWER
Explanation:
C2H6
!!!!!!!!!!
because it has both hydrogen and carbon as given in the word "Hydro-carbon"
Which of the following acids has a basicity of 2?
1 point
ethanoic acid
hydrochloric acid
nitric acid
sulphuric acid
Answer:
its answer is nitric acid...
this may help you...what is the purpose of environmental regulations on chemicals
Answer: EPA regulates the production and distribution of commercial and industrial chemicals, in order to ensure that chemicals for sale and use in the United States do not harm human health or the environment.
Explanation:
Question 7 of 10
How much energy is required to melt 2 kg of aluminum? Use the table below
and this equation: Q- mLfusion
Substance
Latent Heat
Fusion
(melting)
(kJ/kg)
Melting
Point
(°C)
Latent Heat
Vaporization
(boiling) (kJ/kg)
Boiling
Point
("C)
Aluminum
400
660
1100
2450
Copper
207
1083
4730
2566
Gold
628
1063
1720
2808
Helium
5.2
-270
21
-269
Lead
245
327
871
1751
Mercury
11.4
-39
295
357
Water
335
0
2258
100
A. 2200 kJ
B. 800 kJ
C. 1600 kJ
D. 1100 kJ
Answer:
NO 2200! 800 proprobably
Explanation:
just did wrong
Answer:
800 kJ
Explanation:
The below table compares the number of electrons in two neutral atoms.
atom:
Ne 10
Na 11
Compare the electron configuration and atomic radius of these two atoms and use that to explain the difference in their reactivity.
The process of changing a gas to a liquid is known as _____.
sublimation
precipitation
evaporation
condensation
Answer:
Condensation is the process.
A student hypothesized that the amount of sunlight a sunflower plant receives determines the number of sunflower seeds the plant produces. In his experiment,
the number of seeds produces is the
Manipulated variable
ЕОООО
Control variable
Dependent variable
Independent variable
Answer:
Dependent variable
Explanation:
In every experiment, there must be a dependent variable and an independent variable.
The independent variable is that variable that you have to manipulate in order to receive a response. E.g, in the experiment described in the question, the amount of sunlight a sunflower plant receives is the independent variable.
The dependent variable is the number of seeds produced. It is the response obtained by carefully manipulating the amount of sunlight
why doesn't calcium react with water in your body
explain pls
Answer:
Bones aren't made of calcium metal. Bones are a collegun structure filled in with mostly calcium carbonate and some calcium phosphate
Answer:
Bones aren't made of calcium metal. Bones are a collegun structure filled in with mostly calcium carbonate and some calcium phosphate
Explanation:
I hope this helps
Which is a property of all acids?
A. They increase the OH^- concentration in solution.
B. They contain OH^- ions.
C. They contain H3O^+ ions.
D. They increase the H^+ concentration in solution.
Acids increase the [tex]H^+[/tex] concentration in solution. Therefore, the correct option is D.
One of their essential characteristics is the ability of all acids to increase the concentration of H+ ions (protons) in a solution. Acids are chemicals that when dissolved in water add protons to the solution. As a result of this proton donation, the amount of [tex]H^+[/tex]ions in the solution increases, thereby lowering the pH. It is important to remember that not all acids contain[tex]H_3O^+[/tex] ions directly; Instead, [tex]H^+[/tex] ions can react with water molecules to generate [tex]H_3O^+[/tex] ions (hydronium ions).
Therefore, the correct option is D.
Learn more about Acids, here:
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Which reaction will most likely take place based on the activity series? Li > K Ba CaNa > Mn > Zn > Cr> Fe> Cd Ni > H > Sb > Cu > Ag > Pd > Hg > Pt a. Ag+FeCl 3 b, Zn + CaO C. Ba+Na 2 CO 3 d . Cr+KNO3
Answer:
Among the given reactions,
a. Ag+FeCl 3
b, Zn + CaO
C. Ba+Na 2 CO 3
d . Cr+KNO3
which reaction is likely to take place based on the reactivity series?
Explanation:
The metal reactivity series is:
Li > K> Ba >Ca>Na > Mn > Zn > Cr> Fe> Cd Ni > H > Sb > Cu > Ag > Pd > Hg > Pt
The highly reactive metal will displace the less reactive metal from its compound during a displacement reaction.
a. Ag+FeCl 3
Ag is less reactive than Fe, so Ag cannot displace Fe from its compound.
This reaction also does not occur.
b, Zn + CaO
Zn is less reactive than Ca, so it cannot displace Ca from its compound.
This reaction does not occur.
C. Ba+Na 2 CO 3
Ba is more reactive than Na, so Ba displaces Na from its compound.
This reaction is possible.
d . Cr+KNO3
Cr is less reactive than K, so it cannot displace K from its compound.
Hence, This reaction is not possible.
Answer:
option c) Ba+Na 2 CO 3 -> BaCO3 +2Na
Answer:
C. Ba+Na 2 CO 3 -> BaCO3 +2NaIn the diagram shown, what is occurring at the section marked 4?
- Temperature
Heat Energy
O Melting
O Freezing
condensation vaporization
