Answer:
Data is a specific measurement of a variable – it is the value you record in your data sheet.
Explanation:
i dont know if that helps but i hope it does :)
Variables that are known as data while data collection are quantitative variables.
What are variables ?
A variable is any characteristics, number or quantity that can be measured or counted.It is called a variable because the value may vary and can change over a period of time as well.
There are different types of variables based on the ways they can be studied and presented.
Numeric variables have values describing measurable quantities. They are further classified as continuous or discrete.Continuous variable ranges between any set of real numbers.
Discrete variables is a numeric variable whose observation can take a value from a set of distinct whole values.
Ordinal variable is a categorical variable whose value can be logically ranked,whereas a nominal variable is a categorical variable whose observation can take up a value which is not being able to be put up in a logical sequence.
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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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4. NH4Cl
What is the compound?
Answer:
ammonium chloride
Explanation:
Because NH is ammonium and Cl is chlorine
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.
A company employs several high school students in its food-packaging factory. All the students are below 17 years of age. Which act prohibits
the employment of such persons?
OA. Occupational Safety and Health Act
OB. Fair Labor Standards Act
OC. Perishable Agricultural Commodities Act
OD. Homeland Security Presidential Directives
Answer:
Fair Labor Standards Act
Explanation:
It is correct. I just took the test on Clever
Answer:
I would say it’s B
Explanation:
Which statment correctly decribes a law?
can be changed or replaced
is a factual statment
is not based on observations
how many kilojoules is 1,500,000 calories
Answer:
1 cal = 0.004187 kJ
1,500,000 cal = 6280.5 kJ
When 1.20 moles of MgO reacts as completely as possible with 0.900 moles of NaCl, the total number of moles of reaction products is:
MgO (s) + 2 NaCl (aq) → MgCl2 (aq) + Na2O (aq)
Answer:
Explanation:
limiting reactant is NaCl it is consumed completely)
calculate n for each product
n NaCl (mole ) n MgCl2(mole )
2 1
0.9 x
x = 0.45 mole
n NaCl n Na2O
2 1
0.900 x
x = 0.45 mole
the total number of moles of reaction products is: 0.45 + 0.45= 0.9mol
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
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.
What two properties of matter are used to determine density?
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
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]
Two samples of matter differ in temperature by 20°C. Describe
the difference in temperature of these two samples using the
Kelvin scale.
Given :
Two samples of matter differ in temperature by 20°C.
To Find :
The difference in temperature of these two samples using the Kelvin scale.
Solution :
Let , initial and final temperature is [tex]T_i[/tex] and [tex]T_f[/tex] .
So , [tex]T_f-T_i=20^oC[/tex] .
Now , temperature in kelvin is given by [tex](T_i+273)[/tex] and [tex](T_f+273)[/tex] .
So , difference between them is :
[tex]=(T_f+273)-(T_i+273)\\\\=T_f-T_i\\\\=20\ K[/tex]
The difference in temperature of these two samples using the Kelvin scale is 20 K .
Therefore , the magnitude of difference in kelvin and Celsius is same .
Hence , this is the required solution .
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
the amount of water vapour in the air is caleed
Answer:
Absolute humidity
Explanation:
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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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.
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
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
formula that represents a substance that is a mixture
]Answer:
[tex] H_2O + Mg [/tex]
Explanation:
A mixture is made up of two or more substances or constituents, which combine physically and can be easily separated. In a mixture, each constituent still maintains its identity and property in the combination.
Among the options given, the formula [tex] H_2O + Mg [/tex] represents a mixture of Water and Magnesium. This is a typical example of a substance that consists of 2 different substances that are combined physically.
Explain how original mass of dry ice compares with the mass of carbon dioxide gas?
Balancing
equations
• Check that the Synthesis reaction is selected and
that all coefficients are set to one. (The
coefficients are the numbers in the boxes.)
Introduction: The equation H, + O, H,O is unbalanced because there are two oxygen atoms
on the reactants side of the equation, and only one on the products side of the equation. To
balance the equation, you cannot change the structure of any of the molecules, but you can
change the number of molecules that are used.
Question: How are chemical equations balanced?
1. Balance: Tum on Show histograms. The equation is balanced when there are equal
numbers of each type of atom represented on each side of the equation.
In the Gizmo, use the up and down arrows to adjust the numbers of hydrogen, oxygen, and
water molecules until the equation is balanced. When you are done, turn on Show
summary to check your answer.
Write the balanced equation here:
H2+
Н,0
to see other
Synthesis of reaction can be done by adding two or more reactants to form a product.
The chemical equation are balanced according to the law of conservation of mass. It means that the mass of products on the right side should be equal to the mass of reactants on the left.When the number of the product and reactants are equal on both the sides than the equation is said to be balanced.Equation for the water can be balanced as follow:
[tex]2H_{2} + O_{2} = 2H_{2}O[/tex]
The atoms of hydrogen are balanced on both the sides, also the oxygen are balanced.
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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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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 temperature of 0.500 moles of helium that occupies a volume of 15.0 L at a pressure of 1.6 atm?
Answer:
600K
Explanation:
PV=nRT
T=PV/nR
= 1.6atm* 15.0L/ 0.5mol*0.0821LatmK^-1mol^-1
=600K
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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Potassium (K) and calcium fluoride (CaF2) can both be classified as
(Please help)
Calculate the following using the correct significant digits: 12.354 + 17.5?
Answer:
29.854
Explanation:
12+17=29
.354+.5= 854
Which statement describes the formation of metamorphic rocks?
Rocks beneath the surface melt.
Rocks above the surface are eroded.
Rocks beneath the surface are forced toward the mantle.
Rock layers near the surface decrease pressure on layers beneath them.
Answer:
rocks beneath the surface melt seems like the answer that makes the most sense
Answer:
Rocks beneath the surface melt
Explanation:
2) Which one
more active in between
Li and Na and why ?
IS
Answer:
sodium(Na) is more active between Li and Na because is larger in size. Outermost electrons are less tightly held in sodium than in lithium. As a result, sodium loses its outermost electron more easily than lithium.
