Answer:
0.0345L
Explanation:
:)
An electron has a mass
Calculate the following using the correct significant digits: 12.354 + 17.5?
Answer:
29.854
Explanation:
12+17=29
.354+.5= 854
how many kilojoules is 1,500,000 calories
Answer:
1 cal = 0.004187 kJ
1,500,000 cal = 6280.5 kJ
0.5 gm of mixture of NH4Cl and NaCl was boiled with 25 ml of 0.95 N NaOH in a vessel till all the ammonia is expelled.The residual solution is cooled and then made up to 100 ml.It was found that 10 ml of the diluted residual solution neutralised by 16 ml of 0.1 N (F=1.06)H2SO4. Calculate the % of pure NH4Cl in the mixture.
Ans:72.66%
Answer:
72.66%
Explanation:
NH₄Cl reacts in presence of NaOH producing ammonia, NH₃, as follows:
NH₄Cl + NaOH → NaCl + NH₃ + H₂O
The residual NaOH reacts with H₂SO₄ as follows:
2NaOH + H₂SO₄ → Na₂SO₄ + 2H₂O.
The equivalent-gram of H₂SO₄ are:
16mL * 0.1N * 1.06 = 1.696mEq.
As the complete residual solution is 100mL but the neutralization was made only with 10mL, the mEq you need to neutralize the residual NaOH is:
1.696mEq * (100mL / 10mL) = 16.96mEq.
The mEq of NaOH you add in the first are:
25mL * 0.95mEq = 23.75mEq
That means the NaOH that reacts = moles of NH₄Cl is:
23.75mEq - 16.96mEq = 6.79mEq = 6.79mmoles NH₄Cl =
6.79x10⁻³ moles NH₄Cl
In grams (Using molar mass NH₄Cl = 53.5g/mol):
6.79x10⁻³ moles NH₄Cl * (53.5g / mol) =
0.3633g of NH₄Cl are in the original mixture.
% is:
0.3633g/ 0.5g * 100 = 72.66%
The percentage of pure NH₄Cl in the mixture = 72.66%
Given data :
0.5 gm of mixture of NH₄Cl and NaCI
25 ml of 0.95 N NaOH
Determine the % of pure NH₄Cl in the mixture
Given that the reaction equation of the mixture is ;
NH₄Cl + NaOH ----> NaCl + NH₃ + H₂O
And the residual solution reaction with H₂SO₄ is
2NaOH + H₂SO₄ ----> Na₂SO₄ + 2H₂O.
∴ H₂SO₄ ( equivalent gram ) = 16mL * 0.1N * 1.06 = 1.696
but the equivalent gram of H₂SO₄ required to neutralize NaOH = 1.696 * ( 100 mL / 10 mL ) = 16.96
NaOH⁻ = 25mL * 0.95 = 23.75mEq ( from the first reaction equation )
next step : Determine the number of moles of NH₄Cl
moles of NH₄Cl = 23.75- 16.96 = 6.79 * 10⁻³
Final step : Calculate the % of pure NH₄CI in the mixture
moles of NH₄Cl = 6.79 * 10⁻³
molar mass of NH₄Cl = 53.5g/mol
∴ mass of NH₄Cl = 6.79 * 10⁻³ * 53.5 = 0.3633g
% of pure NH₄CI in the mixture = ( 0.3633 / 0.5 ) * 100 = 72.66%
Hence we can conclude that The percentage of pure NH₄Cl in the mixture is 72.66%
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When copper metal is heated to 1100 oC it melts. Is this a chemical or physical change? Explain your answer
Answer:
it is a physical change
An atom has 14 protons, 17 neutrons, and 18 electrons. What is its mass number, atomic number, and charge?
Answer:
Mass number = 31Atomic Number = 14Charge = -4Explanation:
14 protons
17 neutrons
18 electrons
Mass number = ?
Mass number = protons + neutrons.
[tex]Mass\:number = 14+17\\\\Mass \:number = 31[/tex]
Atomic number = ?
The number of protons = atomic number.
Atomic number = 14
Charge = ?
The charge of an element = number of protons minus the number of electrons.
[tex]Charge=14 -18\\\\Charge = -4[/tex]
Is pure Iron a pure substance or mixture
Answer:
Pure iron is a pure substance.
Explanation:
Pure iron is a pure substance because it's chemical composition stays uniform regardless of it's sample size. It's matter that appears uniform in appearance and composition, no matter how small the sample size. An example of a pure substance includes pure iron
To produce 3.00 L of a 1.90 M solution of sodium hydroxide (NaOH), how many grams of sodium hydroxide must be dissolved?
Therefore, to make 3.00 L of a 1.90 M solution of sodium hydroxide, 228 grammes of sodium hydroxide must be dissolved.
For a 1M NaOH solution, how much NaOH dissolves in 1 gallon of water?We need to dilute 40 grammes of sodium hydroxide in one litre of water in order to create a solution with a 1 molar concentration. You can make 1M NaOH solution by weighing 39.9 g of NaOH granules and dissolving them in 1 litre of water.
We can use the following method to calculate the mass of sodium hydroxide needed to make the solution:
m = M × V × MW
where:
m = mass of solute (in grams)
M = molarity of the solution (in moles per liter)
V = volume of the solution (in liters)
MW = molecular weight of the solute (in grams per mole)
Substituting the given values, we get:
m = 1.90 mol/L × 3.00 L × 40.00 g/mol
m = 228 g.
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A chemical property of oxygen is that it ____
a.) is the most abundant element in earth's crust
b.) combines with hydrogen to form water
c.) boils at -183 Celcius
d.) has a density of 1.43 g/l
WILL GIVE BRAINLEST + THANKS! <3
Answer:
the answer you are searching for is
Atoms of different
can be distinguished from
each other by the number of protons (atomic number) in their
nucleus.
Answer:
Elements
Explanation:
An element is defined by the number of protons in its nucleus.
How many protons are in the following atom?
Answer:
This is Lithium and Lithium had 3 protons
Explanation:
Note:The number that is red (3) is the proton number.
The top left number(7) is the nucleon number.
If the question ask the electron number.. It's also 3 because PROTON AND ELECTRON ARE THE SAME
Hope this is correct and helpful
HAVE A GOOD DAY!
Can anybody can solve this PLEASE
Answer:
B has highest stability
Explanation:
as its octet is complete
plz mark brainliest if it helps
What is the mass of a 15mL sample of mercury? (Density of mercury is: 13.55 g/cm3) (show your work)
Answer:
The answer is
203.25 gExplanation:
The mass of a substance when given the density and volume can be found by using the formula
mass = Density × volumeFrom the question
volume of mercury = 15 mL
density = 13.55 g/cm³
The mass is
mass = 13.55 × 15
We have the final answer as
203.25 gHope this helps you
The mere exposure effect _____.
A.happens when familiar things are selectively ignored
B.causes people to dislike things they are familiar with
C.can cause people to reject unfamiliar things
D.is a bias against familiar things
Answer: A
Happens when familiar things are selectively ignored.
HELP THIS HAS TO BE TURNED IN IN AN HOUR
Answer:
B
Explanation:
DONE
One of the following properties was originally used to arrange elements on the periodic table, but is no
longer used to organize the modern version. Which property fits this description?
atomic number
atomic mass
chemical properties
DONE
Intro
FR
Answer:
The correct answer is atomic mass
Explanation:
on engenuity
Answer:
The correct answer is atomic mass.
Explanation:
I took the quiz on edginuity
What two properties of matter are used to determine density?
the amount of water vapour in the air is caleed
Answer:
Absolute humidity
Explanation:
What did researchers at Virginia Tech try using to help reforest post-mining site soil?
Answer:
Researchers at Virginia Tech decided to try using biochar to help reforest the post-mining site soil. They got permission to apply a layer of biochar to a post-mining site before it was reseeded and replanted.
If the chemical reaction AB + CD → AD + BC releases heat, what is true of the stored bond energy of the reactants and products?
Answer:
Being a reaction that releases heat, it is considered exothermic.
Explanation:
That is why if we consider it exothermic, the heat that is released to the medium is chemical energy lost from the interaction between the chemical bonds throughout the reaction. Having said this, we can affirm that the energy of the links of the products IS LESS than that of the REAGENTS, otherwise it happens in the endothermic ones, where it occurs in a vice versa.
These processes tend to have greater entropy and greater disorder in the reaction, greater kinetic energy between the particles.
0.15 gm of metallic oxide was dissolved in 100 ml of 0.1 N H2SO4 and 25.8 ml of 0.095N NaOH were used to neutralise the remaining H2SO4.Calculate the equivalent weight of metallic oxide and metal.
Ans: metallic oxide=19.87
metal=11.87
Answer:
Explanation:
25.8 ml of .095 N NaOH is needed to neutralise the remaining acid
equivalent of NaOH used = 25.8 x .095 / 1000 = .002451 gm equivalent .
acid remaining = .002451 gm equivalent .
acid initially taken = 100 ml of .1 N / 1000 = . 01 gm equivalent
acid reacted with metal = .01 -.002451 = .007549 gm equivalent
This must have reacted with same gram equivalent of metal oxide
.007549 gm equivalent = .15 gm of metal oxide
1 gm equivalent = 19.87 gm
equivalent weight of metal = 19.87 - equivalent weight of oxygen
= 19.87 - 8 = 11.87 .
1
How many valence electrons does the element with the following electron configuration have? 1s22s22p63s23p64s23d104p4
Explanation:
please refer to the attached file (English)
s'il vous plaît se référer au fichier ci-joint cher compagnon (French)
The number of valance electron is 6
Valence electrons are the electrons found in the outermost shell of an atom.
The given atom has the following electronic configuration;
1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁴
The number of valence electron in a given electronic configuration is determine as follows;
if the last configuration ends in s-orbital, the valence electron is the number of electron attached to the s-orbitalif the configuration ends in p-orbital, the number of valence electron is obtained by adding the electrons in p-orbital and s-orbitalThe number of valance electron is found in this sub-orbitals = 4s², 4p⁴
The number of valance electron = 2 + 4 = 6
Thus, the number of valance electron is 6
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Density = 2 g/ml
Volume = 20 ml
What is the mass?
Answer:
The answer is 40 gExplanation:
The mass of a substance when given the density and volume can be found by using the formula
mass = Density × volumeFrom the question
volume = 20 mL
density = 2 g/mL
The mass is
mass = 20 × 2
We have the final answer as
40 gHope this helps you
Explain how original mass of dry ice compares with the mass of carbon dioxide gas?
what is the molecular formula of Alkyne?
Answer:
CnH2n-2 where n is the number of carbon atoms
Explanation:
for example :
pentayne
C5 H (5x2 -2 )
C5H8
Which of the following describes what a scientist does?
Answer:
people who discover new things fyi you dont have any answer choices on there
Explanation:
there are different type of scientist
Answer:
A scientist asks questions about the world.
Explanation:
4. NH4Cl
What is the compound?
Answer:
ammonium chloride
Explanation:
Because NH is ammonium and Cl is chlorine
Which statement describes a property that is unique to metalloids?
Metalloids are shiny.
Metalloids are semiconductive.
O Metalloids are solid.
O Metalloids are brittle.
The statement that described a property that is unique to metalloids would be that they are semiconductive.
Generally, semiconductors are material that at equilibrium between the conductive nature of conductors and non-conductive nature of insulators. In other words, semiconductors are not as conductive as conductors neither are they total insulators.
Semiconductivity is a property that is unique to metalloids because their electrons are more strongly bound to the nucleus of their atoms than those of metals.
Shiny, solid, and brittleness are properties that are shared among a wide variety of materials but semiconductivity is a property that is unique to metalloids.
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Answer: Bbbbb
Explanation:
Plant cells have large central ________________ . These are also found in animal cells but are much smaller Question 3 options: Chloroplast Vacuole Mitochondria Cell Membrane
Answer:
vacuoles
Explanation:
Vacuoles are not only found in animal and plant cells, but on every given diagram vacuoles are huge and singular on a plant cell. Animals however, there are multiple and are much smaller
why do neutral atoms lose or gain electron?
Answer: Atoms that lose electrons acquire a positive charge as a result because they are left with fewer negatively charged electrons to balance the positive charges of the protons in the nucleus. Positively charged ions are called cations.
Atoms are made up of subatomic particles and gain or lose electrons to achieve the full electronic configuration and its octet.
What is an atom?The particle of matter has been constituted of at least a proton termed an atom. The electrons in orbitals and the protons and neutrons organized in a nucleus make up the main components of an atom.
Cations are the name given to ions that donate their electron. While anions are atoms that get extra electrons from other species. Seventeen protons and seventeen electrons make up a neutral chlorine atom. The octet needs one electron to be complete. Chlorine has the electrical configurations 2, 8, and 7, and will remain stable if it accepts an electron from a cation.
Therefore, atoms frequently absorb and lose electrons to maintain stability.
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