Answer:
A molecular mass is mass on the substance and mole is a unit of substance such as atoms and electrons.
Explanation:
A molecular mass is the mass of a molecule of the substance and is called as molecular weight. Molar mass is measured in moles. Mass of one mole is 6.022x10²³ particles and is expressed in grams. The molar mass is said to be the mass of the given substance that is divided by the amount of the substance and s expressed in g/ml.Molecular mass: A molecule's molecular mass is equal to the sum of all of the atoms' individual atomic masses. It establishes the molecular mass of a single unit.
Example:
Molecular mass of O2 = 32 atomic mass units
Mole: A mole is [tex]6.02214076 x 10^2^3[/tex]of any chemical unit, including atoms, molecules, ions, and others. Due to the large number of atoms, molecules, or other components that make up any material, the mole is a useful measure to utilize. The initial definition of the mole was the number of atoms in 12 grams of carbon-12.
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Which statement is true about molarity and percent by mass? (3 points)
They have the same unit.
They are inversely related.
They are different units of dilution.
They are different units of concentration.
Answer:
The guy above used photoshop here is the actual answer.
Explanation:
The true statements about molarity and percent by mass is that they are the different units of concentration
What is concentration?Concentration of any substance present in any solution guves idea about their relative amount in that and it can de described in terms of molarity and percent by mass.
Molarity is define as the moles of solute present in per unit volume of the solution and has a unit of mol/L.Percent by mass is define as the mass of solute present in total mass of solution and it is a unit less quantity.They both gives idea about the concentration, not of the dillutions.They are not inversely related else they are directly related to each other as they are depends on the moles or mass of solute.Hence, molarity and percent by mass are the different units of concentration and directly related to each other.
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Give the number of lone pairs around the central atom and the molecular geometry of SCl2. Multiple Choice 3 lone pairs, linear 1 lone pair, bent 3 lone pairs, bent 0 lone pairs, linear 2 lone pairs, bent
Answer:
2 lone pairs, bent
Explanation:
According to the Valence Shell Electron Pair Repulsion Theory, the number of electron pairs on the valence shell of the central atom in a molecule influences the shape of the molecule.
The presence of lone pairs on the valence shell of the central atom causes the observed molecular geometry to deviate from the ideal geometry predicted on the basis of the valence shell electron pair repulsion theory.
SCl2 has four regions of electron density. This means that its electron domain geometry is tetrahedral. However, there are two lone pairs on the valence shell of the central atom hence the observed molecular geometry is bent.
The Li2+ ion is very similar to the hydrogen atom, in that it has one electron and energy levels similar
to the hydrogen atom. However, the relation = − (
1
2 −
1
2) cannot be used for this ion but
rather the relation = −2+ (
1
2 −
1
2) where the constant 2+=1.96x10-17J.
Use this relation to determine the third ionization energy, which is energy required to remove the last
electron from a Li2+ ion in kJ/mol, if the ion starts off in the ground state (Li2+ → Li3+
+ e-
).
A 250 mL sample of gas at 1.00 atm and has the temperature increased to and the volume increased to 500 mL. What is the new pressure
Answer:
0.53atm = P2
Explanation:
Gas at 1.00atm and 20°C. Temperature increased to 40°C...
We can solve this question using combined gas law:
P1*V1 / T1 = P2*V2 / T2
Where P is pressure, V volume and T absolute temperature of 1, initial state and 2, final state.
Compunting the values of the problem:
P1 = 1.00atm
V1 = 250mL
T1 = 20°C + 273.15 = 293.15K
P2 = ?
V2 = 500mL
T2 = 40°C + 273.15 = 313.15K
1.00atm*250mL / 293.15K = P2*500mL / 313.15K
0.53atm = P2
An unknown compound's 2,4-DNP product melting range is between 144-146'C. It does not give a silver mirror on the Tollens test and is slow to react to the chromic acid test. What would this compound be
Answer:
An unknown compound's 2,4-DNP product melting range is between 144-146'C. It does not give a silver mirror on the Tollens test and is slow to react to the chromic acid test. What would this compound be
Explanation:
From the given data it is clear that the unknown compound gives positive test with 2,4-DNP reagent.
That means it has a carbonyl group.Either aldehyde or ketone.
It does not give a silver mirror on the Tollens test and is slow to react to the chromic acid test.
That means aldehyde is absent.
So, the other carbonyl group that is ketone is present in the given unknown compound.
The energy levels of hydrogenlike one-electron ions of atomic number Z differ from those of hydrogen by a factor of Z^2. Predict the wavelength of the 2s--->1s transition in He+.
Answer:
[tex]\mathbf{\lambda \simeq 3.039 \times 10^{-8} \ m}[/tex]
Explanation:
For a hydrogen-like atom, the spectral line wavelength can be computed by using the formula:
[tex]\bar v = Z^2 R_H \Big(\dfrac{1}{n_f^2}-\dfrac{1}{n_i^2}\Big)[/tex]
where:
emitted radiation of the wavenumber [tex]\bar v[/tex] = ???
atomic no of helium Z = 2
Rydberg's constant [tex]R_H = 1.097*10^7 \ m^{-1}[/tex]
the initial energy of the principal quantum [tex]n_1[/tex] = 2
the initial energy of the principal quantum [tex]n_1[/tex] = 2
Now, the emitted radiation of the wavenumber can be computed as:
[tex]\bar v = (2)^2 (1.097*10^7 \ m^{-1} ) \Big(\dfrac{1}{1^2}-\dfrac{1}{2^2}\Big)[/tex]
[tex]\bar v = 3.291 \times 10^ 7/m[/tex]
Now, the wavelength for the transition can be computed by using the relation between the wavelength λ and the emitted radiation of the wavenumber [tex]\bar v[/tex], which is:
[tex]\bar v = \dfrac{1}{\lambda}[/tex]
[tex]\lambda = \dfrac{1}{\bar v}[/tex]
[tex]\lambda = \dfrac{1}{3.291 \times 10^{7}}\times \dfrac{m}{1}[/tex]
[tex]\mathbf{\lambda =3.03859 \times 10^{-8} \ m}[/tex]
[tex]\mathbf{\lambda \simeq 3.039 \times 10^{-8} \ m}[/tex]
a laser emits light with a frequency of 4.69 x 10 to the 14th power s - 1 calculate the wavelength of this light.
Answer:
6.40x10^-7
Explanation:
answer with work is attached.
(4.184 J——> 1 calorie ? Take your answer from number 1 and convert to the answer into calories?
Answer:
There are 1.195 calories in 5 J.
Explanation:
The relation between calorie and Joules is as follow :
4.184 J = 1 calorie
or
1 J = (1/4.184) calorie
Let the taken number is 5 J
So,
5 J = (5/4.184) calorie
5 J = 1.195 calorie
So, there are 1.195 calories in 5 J.
if salt and sand is mixed with distilled water, what will be the residue and what will be the filtrate?
Answer:
salt and sand
Explanation:it is what it is
Which of the following is true for balancing equations?
A. There must be an equal number of atoms of each element on both sides of the equation.
B. The number of products should be equal to the number of reactants
C. The properties of products should be the same as the properties of the reactants
D. There must be an equal number of compounds on both sides of the equation
Answer:
A.
Explanation:
An equation with the equal amount and proportion of atoms of each element on both sides of the reaction is commonly referred to as a balanced chemical equation.
The law of conservation of matter asserts that no observable and empirical change in the amount of matter occurs within a conventional chemical process. As a result, each element in the product would have the same equal amount or numbers of atoms as the reactants.
I need help with the practice question at the bottom. Thank you.
As the gas expands on the surrounding, work is done by the system.
Therefore, W= -279J
Absorbtion of heat,q= +216J
∆U=q+W = (216-279)J= -63J
A sample of Br2(g) takes 12.0 min to effuse through a membrane. How long would it take the same number of moles of Ar(g) to effuse through the same membrane
Answer:
6 mins
Explanation:
The time taken for Ar to effuse can be obtained as follow:
Time for Br₂ (t₁) = 12 mins
Molar mass of Br₂ (M₁) = 2 × 80 = 160 g/mol
Molar mass of Ar (M₂) = 40 g/mol
Time for Ar (t₂) =?
t₂/t₁= √(M₂/M₁)
t₂ / 12 = √(40/160)
Cross multiply
t₂ = 12 × √(40/160)
t₂ = 12 × 0.5
t₂ = 6 mins
Therefore, it will take 6 mins for the same amount of Ar to effused out.
define the following terms atom
What is the mass number of an ion with 106 electrons, 157 neutrons, and a +1 charge?
Answer:
264 g/mol
Explanation:
#electrons equal #protons = 106
Plus 1 charge => m protons = 106 + 1 = 107
Mass number: 107 + 157 = 264 g/mol
Why do gases act more ideal at
lower pressures?
Answer:
Gases act more ideal at lower pressure beacuse the attractive forces between molecules will decrease or become less significant compared to the empty space between them.
Explanation:
Generally, a gas behaves more like an ideal gas at higher temperature and lower pressure as the potential energy due to intermolecular forces becomes less significant compared with the particles "kinetic energy" and the size of the molecules become less significant compared to the empty space between them.
Attractive forces between molecules, decrease the pressure of a reak gas, slowing the molecules and reducing collisions with the walls.The higher the value of a gas, the greater the attraction between molecules and the more easily the gas will compress.
HOPE IT HELPS MUCHanswered by: John Glenly Pillazo Mahusay
determine the mass in grams of 3.75 x 10^21 atoms of zinc. (the mass of one mole of zinc is 65.39 g)
Answer: The mass in [tex]3.75 \times 10^{21}[/tex] atoms of zinc is 0.405 g.
Explanation:
Given: Atoms of zinc = [tex]3.75 \times 10^{21}[/tex]
It is known that 1 mole of every substance contains [tex]6.022 \times 10^{23}[/tex] atoms. So, the number of moles in given number of atoms is as follows.
[tex]Moles = \frac{3.75 \times 10^{21}}{6.022 \times 10^{23}}\\= 0.622 \times 10^{-2}\\= 0.0062 mol[/tex]
As moles is the mass of a substance divided by its molar mass. So, mass of zinc (molar mass = 65.39 g/mol) is calculated as follows.
[tex]Moles = \frac{mass}{molar mass}\\0.0062 mol = \frac{mass}{65.39 g}\\mass = 0.405 g[/tex]
Thus, we can conclude that the mass in [tex]3.75 \times 10^{21}[/tex] atoms of zinc is 0.405 g.
Og is the noble gas after Rn. To go from [Rn] to [Og], you must fill four subshells (s, p, d, and f) with a total of 32 electrons. Thus, the atomic numbers of 6th and 7th period elements of the same group differ by 32.
a. To go from [Og] to the next noble gas, however, you would theoretically fill five subshells (s, p, d, f, and g). How many electrons are needed to fill all five subshells?
b. Element 106 in the periodic table is Sg Determine the atomic number of the element just below Sg in the periodic table.
Answer:
See explanation
Explanation:
Since we have to fill five subshells in moving from Og to the next noble gas in the eight period, we have to know the maximum electrons contained in each of those subshells;
s= 2, p=6, d= 10, f= 14, g = 18
This means that we need a total of 50 electrons to fill all the five subshells.
Hence, the element just below Sg in the eight period will have an atomic number of 156.
A molecule contains hydrogen bonding if it contains hydrogen covalently bonded to Group of answer choices sulfur, oxygen, or fluorine. oxygen or nitrogen. fluorine, oxygen, or nitrogen. nitrogen, fluorine, oxygen, or nitrogen. chlorine, fluorine, or iodine.
Answer: A molecule contains hydrogen bonding if it contains hydrogen covalently bonded to (fluorine, oxygen, or nitrogen)
Explanation:
A hydrogen bond is a strong dipole-dipole attraction which occurs between
--> the hydrogen atom attached to a strongly electronegative atom, and
--> another strongly electronegative atom with a lone pair of electrons.
When an electronegative atom such as fluorine, oxygen or Nitrogen is bonded to hydrogen, a dipole develops causing the hydrogen to be partially negative. The electrostatic attraction between the partially positive hydrogen atom in one molecule and the partially negative atom of the more electronegative element in another molecule gives rise to the strong dipole-dipole attraction called hydrogen bonding.
Hydrogen fluoride, water and ammonia contain the three most electronegative elements, fluorine, oxygen and nitrogen respectively, linked directly to hydrogen. In addition, lone pairs of electrons are present in the fluorine, oxygen and nitrogen atoms of the three hydrides, making hydrogen bonds to form easily between them. These compounds which exhibits hydrogen bonding always have higher melting and boiling points.
How much would the freezing point of water decrease if 4 mol of sugar were added to 1kg of water?
Answer:
7.44 C is the answer of the question.
Explanation:
Determine whether each phrase describes carboxylic acids or esters.
a. Usually have a sour odor _____________
b. Notable for their pleasant fragrances ___________
c. Do not form hydrogen bonds amongst themselves and have higher vapor pressure _____________
d. Their reactions with base are known as neutralizations ____________
e. Their reactions with base are known as saponifications _____________
Question 65 pts
(07.02 MC)
During a reaction, ΔH for reactants is −750 kJ/mol and ΔH for products is 920 kJ/mol. Which statement is correct about the reaction? (5 points)
Group of answer choices
It is endothermic because the energy required to break bonds in the reactants is less than the energy released when the products are formed.
It is endothermic because the energy required to break bonds in the reactants is greater than the energy released when the products are formed.
It is exothermic because the energy required to break bonds in the reactants is less than the energy released when the products are formed.
It is exothermic because the energy required to break bonds in the reactants is greater than the energy released when the products are formed.
Answer:
It is endothermic because the energy required to break bonds in the reactants is less than the energy released when the products are formed
Explanation:
A reaction may be endothermic or exothermic. In an endothermic reaction, energy is absorbed by the process while in an exothermic process energy is given out by the process.
Recall that the enthalpy change of a reaction = enthalpy of products - enthalpy of reactants
Hence, where the energy required to break bonds in the reactants is less than the energy released when the products are formed, the reaction is endothermic.
For an endothermic reaction, the enthalpy change of the reaction is positive.
In this case, enthalpy of reaction = 920 - (-750) = 1670 kJ/mol
Question 2 Classify the following statement as a prediction, observation, theory, or law. Please be sure to classify the statement exactly as it is written! A helium filled balloon floats.
Answer:
Theory
Explanation:
We are given the statement;
"A helium filled balloon floats."
Now, this statement is an attempt to explain to us why balloons float. And the reason is because they are filled with helium. This is no prediction or law or observation because to find out if the balloons contain helium, there must have been experiments to confirm that.
Thus, the statement in the question is a theory.
I mix together 50.0 mL of 0.100 M NaIO3, 50.00 mL of 0.100 M NaOH, and 10.0 mL of 0.100 M HIO3. What is the pH of the mixture
Answer:
pH = 12.66
Explanation:
The HIO3 reacts with NaOH as follows:
HIO3 + NaOH → H2O + NaIO3
The moles of HIO3 and NaOH added are:
Moles HIO3:
0.0100L * (0.100mol / L) = 0.00100 moles HIO3
Moles NaOH:
0.05000L * (0.100mol / L) = 0.00500 moles NaOH
As moles NaOH > Moles HIO3, the moles of NaOH that remain are:
0.00500mol - 0.00100mol = 0.00400 moles NaOH.
After the reaction you will have only NaOH and NaIO3. As NaIO3 is a salt, the pH of the solution is determined by only NaOH. Its concentration is:
Moles NaOH: 0.00500 moles NaOH
Volume: 50.0mL + 50.0mL + 10.0mL = 110.0mL = 0.110L
Molarity: 0.0455M NaOH = [OH-]
pOH = -log [OH-] = 1.34
pH = 14 - pOH
pH = 12.66pH is the measure of the hydrogen or the hydronium ion in an aqueous solution. The pH of the mixture containing sodium hydroxide is 12.66.
What is pH?pH is the potential of the hydrogen and is given as a negative log of the hydrogen concentration in the aqueous solution.
The balanced chemical reaction can be shown as:
[tex]\rm HIO_{3} + NaOH \rightarrow H_{2}O + NaIO_{3}[/tex]
Moles of iodic acid are calculated as:
[tex]\begin{aligned} \rm moles &= \rm molarity \times volume\\\\&= 0.100 \;\rm M \times 0.0100 \;\rm L \\\\&= 0.00100\;\rm moles\end{aligned}[/tex]
Moles of sodium hydroxide are calculated as:
[tex]\begin{aligned} \rm moles &= \rm molarity \times volume\\\\&= 0.100 \;\rm M \times 0.05000 \;\rm L \\\\&= 0.00500\;\rm moles\end{aligned}[/tex]
The remaining moles of sodium hydroxide are 0.00500mol - 0.00100mol = 0.00400 moles.
The pH of the mixture will be determined by sodium hydroxide, as sodium iodate is a salt.
The molar concentration of sodium hydroxide is calculated as:
[tex]\begin{aligned} \rm M &= \rm \dfrac{moles}{volume}\\\\&= \dfrac{0.00500}{0.110}\\\\&= 0.0455 \;\rm M\end{aligned}[/tex]
pH is calculated as:
[tex]\begin{aligned} \rm pOH &= \rm -log[OH^{-}] = 1.34\\\\\rm pH &= \rm 14 - pOH\\\\\rm pH &= 12.66\end{aligned}[/tex]
Therefore, 12.66 is the pH of the mixture.
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What is the gravitational potential energy of a 1500-kg truck resting on top of a 550-m hill on earth?( earth’s gravitational pull is 9.8m/s2).
Answer:
E = 8085 kJ
Explanation:
Given that,
The mass of a truck, m = 1500 kg
Height, h = 550 m
We need to find the gravitational potential energy of the truck. It can be calculated as follows :
[tex]E=mgh[/tex]
Put all the values,
[tex]E=1500\times 9.8\times 550\\\\E=8085000\ J\\\\or\\\\E=8085\ kJ[/tex]
So, the gravitational potential energy is 8085 kJ.
What is the product of the following reaction? K OC(CH3)3
Answer:
See explanation and image attached
Explanation:
The reaction is an E2 reaction. It is a synchronous reaction.
The base KOC(CH3)3 abstracts a proton as the bromide ion leaves in a single step.
This yields the product as shown in the image attached.
How many g of Al are required to produce 2.8 mol of Al2O3
Answer:
290 g Al₂O₃
General Formulas and Concepts:
Atomic Structure
Reading a Periodic TableMolesStoichiometry
Using Dimensional AnalysisExplanation:
Step 1: Define
[Given] 2.8 mol Al₂O₃
[Solve] g Al₂O₃
Step 2: Identify Conversions
[PT] Molar Mass of Al: 26.98 g/mol
[PT] Molar Mass of O: 16.00 g/mol
Molar Mass of Al₂O₃: 2(26.98) + 3(16.00) = 101.96 g/mol
Step 3: Convert
[DA] Set up: [tex]\displaystyle 2.8 \ mol \ Al_2O_3(\frac{101.96 \ g \ Al_2O_3}{1 \ mol \ Al_2O_3})[/tex][DA] Multiply [Cancel out units]: [tex]\displaystyle 285.488 \ g \ Al_2O_3[/tex]Step 4: Check
Follow sig fig rules and round. We are given 2 sig figs.
285.488 g Al₂O₃ ≈ 290 g Al₂O₃
Topic: AP Chemistry
Unit: Atomic Structure
A ball is thrown straight up into the air with a speed of 21 m/s. If the ball has a mass of 0.1 kg, how high does the ball go? Acceleration due to gravity is g = 9.8 m/s^2
Answer:
answer = 22.5m
Explanation:
using
[tex]s = \frac{ {v}^{2} - {4}^{2} }{2a} [/tex]
s= (0²-21²)/2(-9.8)
s= -441/19.6
s= 22.5m
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A. Directions:Describe ways on how to protect humans and plants and animals Choose your answer in the box and fill in the concept map below
Answer:
i) Humans - drinks lot of water
- use umbrella
- use hats and sunglasses
- apply sunblock when swimming
- wear rush guard
ii) Plants - water the plants
-put a shade on the plants
iii) Animals - provide pets with plenty of water
- place the animals under the tree during noon time
A major component of gasoline is octane when octane is burned in air it chemically reacts with oxygen to produce carbon dioxide and water what mass of carbon dioxide is produced by the reaction of oxygen
gasoline is the chemical that is coming out of the air
why might the melting point of the crystals obtained in this experiment be close to but below one of the reference melting points and melt slowly over several degrees
Answer: hello the experiment related to your question is missing but I will provide a more general answer within the scope of your question
answer :
presence of Impurities
Explanation:
The melting point of the crystals as obtained in the experiment will be close to but below reference melting points and will also melt slower because of the presence of impurities in the compound
Impurities alter the melting and freezing points from ideal freezing and melting points of compounds
