Answer:
2.67g of NH4Cl are required
Explanation:
Molarity is an unit of concentration in chemistry defined as the moles of solute (In this case, NH4Cl), per liter of solution.
To prepare 100mL of a 0.50M are required:
100mL = 0.100L * (0.50 moles / L) = 0.0500 moles NH4Cl
As molar mass of NH4Cl is 53.491g/mol:
0.0500 moles * (53.491g / mol) =
2.67g of NH4Cl are requiredAre electron shells or orbitals actually inside the atom or are they outside of the structure of the atom?
Answer:
Electrons in atoms occupy energy levels, also called electron shells, outside the nucleus . Different shells can hold different maximum numbers of electrons. The electrons in an atom occupy the lowest available energy level first. This is the shell nearest the nucleus.
Explanation:
explain how of hope's apparatus can be used to demonstrate anomalous behaviour and water class 10
Answer:
The anomalous expansion of water refers to the fact that water, unlike most substances, expands when it freezes. The density of water increases as temperature decreases, but reaches a maximum at 4 degrees C then begins to expand. The significance of this is that ice is less dense than water so it floats in water.
This is of major biological importance. Lakes, ponds and streams freeze from the top down instead of from the bottom.
Four scientist collected data on the blood pressure of 30 people. Which scientist most likely had a problem with the experimental design?
Answer:
Scientist 3
Explanation:
If you use 65.34 g of Al2S3, how many grams of AICl3 can be produced?
Answer:
sorry po
indi ko po maintindihan
22. Sodium-24 has a half-life of 15 hours. How much sodium-24 will remain in an 42.0-g sample after 90 hours?
Answer:
The answer would be 0.65625
A gas of certain mass occupies a volume of 650cm^3 under a pressure of 750 mm Hg. Calculate the pressure under which the volume of gas will be reduced by 10 percent of its original volume.
Answer:
7500 mmHg
Explanation:
From the question,
Applying Boyles Law,
PV = P'V'................ Equation 1
Where P = original pressure, P' = final pressure, V = Original Volume, V' = Final Volume.
make P' The subject of the equation
P' = PV/V'.............. Equation 2
Given: P = 650 cm³, P = 750 mmHg, V' = (650×10/100) = 65 cm³ (Reduced by 10 percent of it original volume)
Substitute these values into equation 2
P' = (650×750)/65
P' = 7500 mmHg
A graduated cylinder was filled with 25.0 mL of water. A solid object was immersed in the cylinder, raising the water level to 32.9 mL. The volume of the object was calculated as 7.9 mL. The solid has a mass of 69.2 grams. What is the density of the object?
Answer:
Density of the object is 8759.494 grams/L
Explanation:
As we know density of an object is mass of the object divided by its volume
Given
Volume of the object is equal to the change in volume of water with in the cylinder when the object was immersed in water.
Hence, volume of object is equal to
[tex]32.9 -25 = 7.9[/tex] mL
Mass of the object is [tex]69.2[/tex] grams
Density
[tex]= \frac{69.2}{7.9 *10^{-3}}\\= 8759.494[/tex] grams/L
Density of the object is 8759.494 grams/L
How many grams of water can be vaporized by 2.153 kJ of energy?
Answer:
That is, water has a high heat of vaporization, the amount of energy needed to change one gram of a liquid substance to a gas at constant temperature. Wate
Explanation:
What type of shape do solids have?
hope it helps :-). good morning.
Explain how the hypothalamus and certain endocrine glands work together to maintain the following conditions in the body. Specify the endocrine glands involve and the hormones it releases.
Answer:
Nerve cells in the hypothalamus make chemicals that control the release of hormones secreted from the pituitary gland. The hypothalamus gathers information sensed by the brain (such as the surrounding temperature, light exposure, and feelings) and sends it to the pituitary.
Explanation:
do you really get 7 years of bad luck if you crack a mirror :(
Answer:
nope its a myth don't worry :)
The compound calcium carbonate contains the calcium ion (Ca2+) and the polyatomic carbonate ion (CO32-). Explain why calcium carbonate is considered to be an ionic compound when it contains both ionic and covalent bonds.
Answer:
Because of the electronegativity difference C-O (covalent) and Ca-O (ionic) bonds have.
Explanation:
Hello there!
In this case, in order to understand the polarity of this compound, calcium carbonate, it firstly necessary that it is comes from the definition of electronegativity, as a property defining the capacity to attract electrons from another atom; thus, since the electronegativities of calcium, carbon an oxygen are 1.0, 2.55 and 3.44, it is possible to realize this compound has O-Ca and O-C bonds according to its Lewis dot structure. In such a way, we calculate the difference electronegativity for these two bonds:
[tex]\Delta E_{O-Ca}=3.44-1.0 = 2.44\\\\\Delta E_{O-C}=3.44-2.55=0.89[/tex]
Thus, since 2.44 accounts for an ionic bond and 0.89 for a covalent one, we bear out the given statement in the question.
In the illustration, which solute will dissolve first?
00.0
00.0
tanka
tank
Solute in Tanks A and B will dissolve at equal rates.
Solute in Tonk Awill dissolve first
Soluten Tork B wil dissolves
The first to dissolve is the solute in tank B. The amount of a substance that dissolves in a specific solvent concentration at a specific temperature is known as its solubility.
Which phase of the dissolving process is the first?The introduction of a solute to a solvent is the first stage in the dissolving process. The molecules of these two substances begin to interact, causing the solute molecules to disperse and become encircled by solvent molecules.
Which of the following three compounds dissolves in water?In water, salt, sugar, and coffee all dissolve. They disintegrate quickly. They typically dissolve more rapidly and completely in hot or warm water. Even very hot water won't be able to dissolve sand or pepper.
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PLEASE ANSWER ASAP!!!! i need it now
Answer:
não sei ainda mas acho que e A
Answer:
e c f
Explanation:
read the question and it tells you how to do it and I can get you to help
1.How many grams of zinc Zn and oxygen O2 will be needed to form 324 grams of ZnO after the reaction?
Answer: pretty sure its 0.214 moles * 40.3g/mole = 8.6g (2 sig figs) of MgO, and
0.035 moles * 40.3g/mole = 1.4g of MgO
Explanation:
What kind of elements are on the left side of the zig-zag line on the periodic table?
Answer:
Metals are found to the left of the zigzag line on the periodic table. B. Nonmetals Nonmetals are found to the right of the zigzag line on the periodic table.
Explanation:
Please help!! I have 10 minutes left!!
Answer:
I believe it is hydrogen for the first and methane for the second.
Explanation:
Answer to 8: The most dangerous or harmful gas to humans in the atmosphere would be carbon dioxide. But reserchers have found that methane levels in ancient air samples and found that scientists have been vastly underestimating the amount of methane humans are emitting into the atmosphere via fossil fuels.
Answer to 7: The type of gases present are as critical to density as elevation and gravity, and all are interrelated. Certain atmospheric gases will create thick atmospheres. For example, atmospheres with abundant hydrogen tend to be thicker as gases will combine with hydrogen for greater mass.
Hope this helps!
pls help!!!!
Predict the missing component
in the nuclear equation.
1331 → X + -e
A
B
с
131 Cs
131Xe
1311
55
54
53
Answer: b
Explanation:
its b
The missing component in the nuclear equation.1331 → X + -e will be 131Xe54. option B is correct.
What is nuclear reaction?The particles in the nucleus are changed, and one element is transformed into another element when particles in the nucleus are gained or lost.
Nuclear reactions are processes in which one or more nuclides are produced from the collisions between two atomic nuclei or one atomic nucleus and a subatomic particle.
This was the first observation of an induced nuclear reaction, that is, a reaction in which particles from one decay are used to transform another atomic nucleus.
The most notable man-controlled nuclear reaction is the fission reaction which occurs in nuclear reactors. A target nucleus are within the range of nuclear forces for the time allowing for a large number of interactions between nucleons.
therefore , option B is correct.
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What is an important effect of gravity?
A. It causes radioactive particles to split off from the nucleus.
B. It is responsible for charge attraction.
C. It keeps the nucleus of the atom together.
D. It maintains the distances between planets.
SUBMIT
Answer:
d. It maintains the distances between planets.
Explanation:
If you want to make 174 grams of NiFz, how many moles of HF will you need, using
the following balanced chemical equation? Ni + 2 HF - NiF2 + H2
Answer:
3.6mol
Explanation:
The balanced chemical equation of this reaction is given as follows:
Ni + 2HF → NiF2 + H2
Based on the above equation, 2 moles of HF will react to produce 1 mole of NiF2.
According to this question, to make 174 grams of NiF2, we find the number of moles of HF required. However, we first convert the mass value of NiF2 to mole value using;
mole = mass/molar mass
Molar mass of NiF2 = 58.7 + 19(2)
= 58.7 + 38
= 96.7g/mol
mole = 174/96.7
mole = 1.799mol of NiF2
Hence, if 2 moles of HF will react to produce 1 mole of NiF2.
- 1.799mol of NiF2 will require (1.799 × 2) = 3.598
= 3.6mol of HF.
How many moles are in 1.4 x 10^21 atoms of sodium?
Answer:
devide by avogadro constant 6.02*10^23
Explanation:
If I add 25mL of water to 125 mL of 0.25 M NaOH solution, what will the molarity of the diluted solution be?
Answer:
0.208333 M
Explanation:
M2=M1V1/V2=(0.25 M)(125mL)/(125mL+25 mL)= 0.208333 M
A 0.239 gram sample of a gas in a 100-ml flask exerts a pressure of 603 mm Hg at 14 Celsius. What is the gas? (Hint: don’t forget BRINCLHOF)
A) chlorine
B) nitrogen
C) krypton
D) xenon
D) oxygen
Please help me and explain how u got ur answer
Answer:
A) chlorine
Explanation:
To solve this question we can use:
PV = nRT
In order to solve the moles of the gas. With the moles and the mass we can find the molar mass of the gas to have an idea of its identy:
PV = nRT
PV / RT = n
Where P is pressure: 603mmHg * (1atm / 760mmHg) = 0.7934atm
V = 100mL = 0.100L
R is gas constant = 0.082atmL/molK
T is absolute temperature = 14°C + 273.15 = 287.15K
0.7934atm*0.100L / 0.082atmL/molK*287.15K = n
3.37x10⁻³ moles of the gas
In 0.239g. The molar mass is:
0.239g / 3.37x10⁻³ moles = 70.9g/mol
The gas with this molar mass is Chlorine, Cl₂:
A) chlorineWhat are the symbols (in order) for hydrogen, sodium and nitrogen?
Answer:
H, Na, N
Explanation:
Answer:
H, NA, N
Explanation
Which of the following metals would be the best to choose for making jewellery? Aluminium, iron, copper or gold?
Answer:
Of course the answer is gold
Explanation:
Gold is used for making jewellery and not aluminium,iron or copper
Answer:
copper or gold.
Explanation:
Copper is also a good material for accessories. Even in the ancient times, those who can’t afford gold jewelry wear copper jewelry instead. It offers design flexibility too due to its high ductility.
Which element, when combined with phosphorus, would form an ionic compound?
A) Carbon.
B)Oxygen.
C)Magnesium.
D)Boron.
There are two types of chemical compound one is covalent compound and other is ionic compound, covalent compound formed by sharing of electron and ionic compound formed by complete transfer of electron. Therefore, the correct option is option C.
What is chemical Compound?Chemical Compound is a combination of molecule, Molecule forms by combination of element and element forms by combination of atoms in fixed proportion.
An ionic compound is a metal and nonmetal combined compound. Ionic compound are very hard. They have high melting and boiling point because of strong ion bond.
Since phosphorus is a nonmetal, we need a metal. Out of given option the only element that is metal is Magnesium while others are non metal.
Therefore, the correct option is option C.
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I need this question ASAP please
Answer:
Heeeeeeeeeeeeeloooooooooo
Explanation:
B. Calculate the Pressure of 20.0 mole of helium in a 10.0 L cylinder at 273 K. [a = 0.0341 atm*L^2/mol^2 ; b = 0.0237L/mol ; R = 0.08205 L*atm/mol*K) *
87.3 atm
46.9 atm
55.5 atm
12 kPa
Answer:
46.9 atm
Explanation:
Applying Van der waals equation
P = [nRT/(V-nb)]- (an²/V²)............... Equation 1
Where P = pressure, T = temperature, n = number of moles, V = volume, R = Universal constant, a and b = gas constant
Given: n = 20 moles, R = 0.08205 L.atm/mol.K, T = 273 K, V = 10.0 L, a = 0.0341 atm.L²/mol², b = 0.0237L/mol
Substitute these values into equation 1
P = [(20×0.08205×273)/(10-20×0.0237)]-(0.0341×20²/10²)
P = (447.993/9.526)-0.1364
P = 47.028-0.1364
P = 46.9 atm
BRAINLIESTT
The pH of a solution is 8.43. What is it {H3O+}concentration?
A. 3.7 x 10-3
B. 2.7 x 10-6
C. 1.0 x 10-14
D. 1.0 x 10-8.43
Answer:
D. 1.0 x 10-8.43
Explanation:
The pH is an unit of concentration in chemistry used to determine the acidity -or basicity- of a particular solution. Is used in quality control to determine the security of a product for consumers.
The equation is:
pH = -log [H₃O⁺]
As pH = 8.43:
8.43 = -log [H₃O⁺]
10^-8.43 = [H₃O⁺]
1.0x10 -8.43 = [H₃O⁺]
Right option is:
D. 1.0 x 10-8.43What is the pOH of a solution that has an H+=7.7x10^-7 M
Answer:
Explanation:
Step 1
The question is based on the concept of PH and pOH calculations.
pH is defined as negative logarithmic of hydronium Ion concentration.
while pOH is defined as negative logarithmic of hydroxide ion concentration of the solution.
Step 2
[H+] = 7.7*10-7 M
pH = -log[H+]
= -log ( 7.7*10-7 )
= 6.12
Step 3
pOH = 14 - pH
= 14 - 6.11
= 7.89