Answer:
a.) 86.01 g.
b.) 3.36 g.
c.) 0.394 m ≅ 0.40 m.
d.) 4.77%.
e.) 3.9%.
Explanation:
a.) mass of the solution:
The density of the solution is the mass per unit volume.
∵ Density of solution = (mass of solution)/(volume of the solution).
∴ Mass of the solution = (density of solution)*(volume of the solution) = (1.22 g/mL)*(70.5 mL) = 86.01 g.
b.) grams of sodium bromide :
Molarity (M) is defined as the no. of moles of solute dissolved per 1.0 L of the solution.∵ M = (no. of moles of NaBr)/(Volume of the solution (L))
∴ no. of moles of NaBr = M*(Volume of the solution (L)) = (0.463 M )*(0.0705 L) = 0.0326 mol.
∵ no. of moles of NaBr = (mass of NaBr)/(molar mass of NaBr)
∴ mass of NaBr = (no. of moles of NaBr)*(molar mass of NaBr) = (0.0326 mol)*(102.894 g/mol) = 3.36 g.
c.) molality of the solution:
Molality (m) is defined as the no. of moles of solute dissolved per 1.0 kg of the solvent.∵ m = (no. of moles of NaBr)/(mass of the soluvent (kg))
no. of moles of NaBr = 0.0326 mol,
mass of solvent = mass of the solution - mass of NaBr = 86.01 g - 3.36 g = 82.65 g = 0.08265 kg.
∴ m = (no. of moles of NaBr)/(mass of the soluvent (kg)) = (0.0326 mol)/(0.08265 kg) = 0.394 m ≅ 0.40 m.
d.) % (m/v) of the solution:
∵ (m/v)% = [(mass of solute) /(volume of the solution)]* 100
∴ (m/v)% = [(3.36 g)/(70.5 mL)]* 100 = 4.77%.
e.) % (m/m) of the solution:
∵ (m/m)% = [(mass of solute) /(mass of the solution)]* 100
∴ (m/m)% = [(3.36 g)/(86.01 g)] * 100 = 3.9 %.
Balance the following equation. Choose "blank" if no coefficient other than 1 is needed.
Choose Pb + Choose AgNO 3 Choose Pb(NO 3 ) 2 + Choose Ag
Answer:
Pb + 2AgNO3 ---> Pb(NO3)2 + 2Ag
Explanation:
The lead Pb2+ ion has a valency of 2 and therefore combines with 2 nitrate ions (NO3)-..
[tex]Pb + 2AgNO_3[/tex] → [tex]Pb(NO_3)_2 + 2Ag[/tex]
What is a balanced chemical equation?An equation that has an equal number of atoms of each element on both sides of the equation is called a balanced chemical equation.
[tex]Pb + 2AgNO_3[/tex] → [tex]Pb(NO_3)_2 + 2Ag[/tex]
This is the balanced chemical equation. Where there are 1 Pb, 2 Ag, 2N, and 6 oxygen atoms on both sides.
Learn more about the chemical equation here:
https://brainly.com/question/15052184
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what kind of bond is ca-br
Final answer:
The bond between calcium (Ca) and bromine (Br) is an ionic bond, where calcium donates electrons to form Ca2+ ions, and bromine atoms each gain an electron to form Br- ions, creating an ionic compound.
Explanation:
The bond between calcium (Ca) and bromine (Br) in the compound CaBr2 is an ionic bond. This type of bond is formed when one atom (in this case, calcium) donates one or more electrons to another atom (in this case, bromine).
Calcium is a metal with a tendency to lose electrons and form a positive ion (Ca2+), while bromine is a non-metal with a tendency to gain electrons and form a negative ion (Br−).
When calcium gives up two electrons, one for each bromine atom, each bromine atom gains one electron, resulting in two Br− ions. These oppositely charged ions attract each other, creating an ionic bond.
how does nuclear reactor produce electricty
With a process called Fission. This generates heat to produce steam.
A device used to measure small currents is a(n)
Answer:
Ammeter
Explanation:
An ammeter (from Ampere Meter) is a measuring instrument used to measure the current in a circuit. Electric currents are measured in amperes (A), hence the name. Instruments used to measure smaller currents, in the milliampere or microampere range, are designated as milliammeters or microammeters.
Need help on this ASAP !!!!
Answer:
N₂ + 3H₂ → 2NH₃. "synthesis reaction".
Explanation:
To balance the equation, you should apply the law of conservation of mass for the equations.
The law of conservation of mass states that the no. of each atom is equal in both sides (reactants and products).
The balanced equation is:
N₂ + 3H₂ → 2NH₃.
It is a synthesis reaction that 2 reactants give 1 product.
That 1.0 mole of N₂ reacts with 3.0 moles of H₂ to produce 2.0 moles of NH₃.
The no. of all atoms is the same in both of reactants and products side.
N (2), and H (6).
what is lithosphere
Answer:
the rigid outer part of the earth, made up of the crust and upper mantle.
Explanation:
Google’s definition
A lithosphere is the rigid, outermost shell of a terrestrial-type planet, or natural satellite, that is defined by its rigid mechanical properties. On Earth, it is composed of the crust and the portion of the upper mantle that behaves elastically on time scales of thousands of years or greater.
the equivalent weight of sodium thiosulfate
The equivalent weight is the gram molecular weight divided by the number of electrons lost or gained by each molecule; For sodium thiosulfate (Na2S2O3·5H2O), this is (248.17/1) g.
What is the pOH of a solution of HNO3 that has [OH– ] = 9.50 × 10–9 M?
Answer:
pOH = 8.02
Explanation:
Given:
[OH-] concentration for HNO3 solution = 9.50*10^-9 M
To determine:
pOH of the above solution
Explanation:
pOH of a given solution refers to the concentration of OH- ions i.e. the degree of basicity of that solution
[tex]pOH = -log[OH-]\\\\For\ the \ HNO3\ solution:\\\\pOH = -log(9.50*10^{-9}) = 8.02[/tex]
When 24g of magnesium metal is heated in air, 40g of magnesium oxide is produced. What mass of magnesium would be needed in order to produce 10g of magnesium oxide?
Final answer:
To produce 10g of magnesium oxide, 6g of magnesium would be needed.
Explanation:
To find the mass of magnesium needed to produce 10g of magnesium oxide, we can use the given information about the reaction between magnesium and oxygen. From the given information, we know that when 24g of magnesium is heated in air, 40g of magnesium oxide is produced. This means that the reaction produces a 1:1 ratio between the mass of magnesium and the mass of magnesium oxide. Therefore, if 24g of magnesium produces 40g of magnesium oxide, then 10g of magnesium oxide would require (10g/40g) * 24g = 6g of magnesium.
During a lunar eclipse, the moon appears to be darkened because _______________ is casting a shadow on it.
the earth
the sun
Mars
Answer:
the earth
Explanation:
because the moon is blocking the light of the sun
Choose the number of significant figures indicated 0.06
Answer:
2
Explanation:
What happens during a endothermic reaction
An endothermic reaction occurs when the energy used to break the bonds in the reactants is greater than the energy given out when bonds are formed in the products. This means that overall the reaction takes in energy, therefore there is a temperature decrease in the surroundings.
Answer:
There is a temperature decrease in the surroundings
Explanation:
An endothermic reaction occurs when the energy used to break the bonds in the reactants is greater than the energy given out when bonds are formed in the products. This means that overall the reaction takes in energy, therefore there is a temperature decrease in the surroundings
What was Pangaea?when did it form and when did it break apart it was
Pangaea was a supercontinent. It is the last supercontinent that had all of the continental masses joined as one, though after its breaking apart there were two other supercontinents which were very short lasting. This supercontinent formed from the pre-existing continental masses that moved toward one another and merged by the late Paleozoic era, approximately around 335 million years ago. Pangaea existed until the early Mesozoic era, and it started to break apart around 175 million years ago. From the breaking apart of this supercontinent, initially formed Laurasia and Gondwanaland, and from the further breaking apart of these two we got the modern day continents.
how many grams of silver chromate, Ag2CrO4, are produced from 57.7
g of silver nitrate, AgNO3?
what is an extensive property? ( in regards to enthalpy )
The extensive properties come under physical property which depends on the size of the system. The enthalpy comes under extensive property which is a thermodynamic property where the internal energy; and the pressure and volume of the system is related.
The change in enthalpy is related to energy transfer at certain pressure which is related to the endothermic and exothermic reactions taking place on the system. Since, all these reactions and heat transfer from the system to the environment is based on the physical property, enthalpy is called as extensive property.
If an object moves faster and faster, what must change?
The energy speed!!!!
what is the percent composition of iron in FeCl3
Final answer:
The percent composition of iron in FeCl3 is 34.43%.
Explanation:
The percent composition of iron in FeCl3 can be calculated by dividing the mass of iron by the molar mass of FeCl3 and multiplying by 100%. FeCl3 consists of one iron atom and three chlorine atoms. The atomic mass of iron is 55.845 g/mol and the atomic mass of chlorine is 35.453 g/mol. Therefore, the molar mass of FeCl3 is 55.845 g/mol + 3 * 35.453 g/mol = 162.204 g/mol. The mass of iron in FeCl3 is 55.845 g/mol / 162.204 g/mol * 100% = 34.43%.
Metalic element in list.
Metallic element in list of paper is Titan.
In both liquid water and ice, a hydrogen bond forms between _____.
a) a pair of oxygen atoms on adjacent molecules
b) the oxygen atom of one molecule and a hydrogen atom of an adjacent molecule
c) a pair of hydrogen atoms on adjacent molecules
d) an oxygen atom and a hydrogen atom in the same molecule
Answer:
b) the oxygen atom of one molecule and a hydrogen atom of an adjacent molecule
Explanation:
In a H₂O molecule there are two O-H bonds. The O atom being more electronegative pulls away the shared pair of electron in the covalent bond more towards itself thus O gaining a partial negative charge and H atom getting a partial positive charge. Thus a dipole exists in the O-H bond in the H₂O molecules. Thus in both liquid water and solid ice there is a weak attraction or hydrogen bond between the oxygen atom of one H₂O molecule and a hydrogen atom of an adjacent H₂O molecule.
Which of these extends the farthest out into the ocean ( beach berm or shore)
Answer:
berm
a berm can be somethint in the middle or water and you can see it once the water go down oe dryes
Using the concentration of the base and the volume of the base used, calculate the moles of the base used in the titration. Then, using the mass of the acid, determine the molar mass of the acid.
Data:
Concentration of the Base(NaOH)= 0.19 M
Volume of the Base used= 8.72 mL
Mass of the Acid(unknown)= 0.33 g
Answer:
[tex]\boxed{\text{(a) 0.001 66 mol MOH; (b) 200 g/mol}}[/tex]
Explanation:
I am assuming that the unknown acid is monobasic. Then the general equation for the reaction is
HA + MOH ⟶ MA + H₂O
(a) Moles of MOH
[tex]\text{Moles of MOH}= \text{0.008 72 L MOH} \times \dfrac{\text{0.19 mol MOH}}{\text{1 L MOH}} = \text{0.001 66 mol MOH}[/tex]
(b) Moles of HA
Now, you use the molar ratio from the balanced chemical equation to find the moles of unknown acid.
[tex]\text{Moles of HA = 0.001 66 mol MOH} \times \dfrac {\text{1 mol HA}}{\text{1 mol MOH }} = \text{0.001 66 mol HA}[/tex]
(c) Molar mass of HA
[tex]\text{MM} =\dfrac{\text{mass}}{\text{moles}}= \dfrac{\text{0.33 g}}{\text{0.001 66 mol}} = \text{200 g/mol}[/tex]
The molar mass of the unknown acid is [tex]\boxed{\textbf{200 g/mol}}[/tex]
What is the mass of oxygen atoms in 1 mole of water
The mass of oxygen atoms in 1 mole of water is 16 grams.
Explanation:This can be calculated by looking at the molecular formula of water, which is H2O. From this formula, we know that one molecule of water contains two hydrogen (H) atoms and one oxygen (O) atom.
Given that the molar mass of hydrogen is 1 gram/mole and the molar mass of oxygen is 16 grams/mole, we can determine that the mass ratio of hydrogen to oxygen in a water molecule is 2:1.
Therefore, in 1 mole of water, we have 2 moles of hydrogen atoms and 1 mole of oxygen atoms.
Multiplying the molar mass of oxygen (16 grams/mole) by the number of moles (1 mole) gives us a mass of 16 grams for the oxygen atoms in 1 mole of water.
A fact is something that has been proven to be true.
True
False
i am in a test :/
Answer:
True.
Explanation:
the answer to your question is True !
Describe an object that is transparent. What quality makes it transparent?
Answer: Water
Explanation: Water is an example of transparent because light can pass through it. Air is also an example.
Final answer:
A transparent object, such as a clean glass window, transmits light without significant absorption or reflection. The quality that makes an object transparent is its ability to let light pass through it effectively, as seen in high-quality diamonds, which refract white light and disperse it into its composite colors, causing a sparkling effect.
Explanation:
An object that is transparent allows light to pass through it without scattering, making it possible to see through the object clearly. A common everyday example of a transparent object is a clean glass window. Glass is transparent because it transmits light rather than absorbing or reflecting it, thus allowing a high proportion of the light spectrum to pass through without significant distortion.
The quality that makes an object transparent is its ability to transmit light waves effectively. When light encounters a transparent material, the photons that make up the light are not significantly absorbed by the material's atoms or reflected away, but rather they pass through the atomic structure of the material without being scattered.
A perfect example of this phenomenon is a high-quality diamond, which is clear and colorless, transmitting all visible wavelengths of light. The diamond sparkles with flashes of brilliant color when illuminated by white light because it refracts, or bends, the light, splitting it into its composite colors in a process similar to a prism. This is known as dispersion, which coupled with the internal reflections within the diamond due to its cut and high refractive index, causes the sparkle with various colors.
Consider the following reaction:
iron (s) + chlorine (g) à iron (III) chloride
a. Write the balanced chemical equation.
b. 25.0 g of iron reacts with excess chlorine gas.
a. Calculate the moles of iron reactant.
b. Calculate the moles of iron (III) chloride.
c. Calculate the mass of iron (III) chloride.
Answer:
Explanation:
Fe + Cl₂ → FeCl₃
a. The balanced equation
All chemical equations obey the law of conservation of matter. To balance this above equation, we either inspect or use mathematical method to obtain a balanced equation.
We put coefficients a, b and c at the back of the compounds as shown below:
aFe + bCl₂ → cFeCl₃
For Fe:
a = c (i)
For Cl:
2b = 3c (ii)
let a = 1, c= 1
Solving for the unknown b, we have:
b = [tex]\frac{3c}{2}[/tex]
b = [tex]\frac{3}{2}[/tex]
The complete reaction equation is therefore:
Fe + [tex]\frac{3}{2}[/tex]Cl₂ → FeCl₃
or
2Fe + 3Cl₂ → 2FeCl₃
Problem a:
Mass of reacting iron = 25g
unknown: number of moles of iron
Solution
To find the number of moles, we apply the mole concept using the expression below:
[tex]number of moles = \frac{mass}{molar mass} \\[/tex]
To find the molar mass of the reactant iron, we know atomic mass of iron is 56g.
The molar mass is therefore, 56gmol⁻¹
[tex]number of moles = \frac{25}{56} \\[/tex]
number of moles of the iron reactant = 0.45mole
Problem b:
From the balanced equation of the reaction:
2Fe + 3Cl₂ → 2FeCl₃
2 moles of Fe produces 2 moles of FeCl₃
So 0.45mole of Fe would produce 0.45 mole of FeCl₃
Problem C:
Applying the mole concept;
mass of FeCl₃ = number of moles of FeCl₃ x molar mass of FeCl₃
number of moles of FeCl₃ = 0.45mole
molar mass of FeCl₃ = ?
Atomic mass of Fe = 56g
Cl = 35.5g
Molar mass of FeCl₃ = 56 + (3 x 35.5) = 56 + 106.5 = 162.5gmol⁻¹
mass of FeCl₃ = 0.45 x 162.5 = 73.1g
What is true of acids?
a.They are poor electrolytes.
b.They have a pH above 9.
c.They have a pH below 7.
d.They have a strong affinity for H ions.
Acids have a pH below 7 (option c), indicating a higher concentration of hydronium ions.
The correct answer is: c. They have a pH below 7.
In chemistry, acids are substances that have a pH value lower than 7. This lower pH indicates a higher concentration of hydronium ions (H₃O⁺) compared to pure water. For example, vinegar, which tastes sour, is an acid with a pH lower than 7. Strong acids are particularly notable for being able to damage materials, demonstrating their high acidity.
Here's why the other options are incorrect:
a. They are poor electrolytes.: Acids are actually good electrolytes, meaning they can conduct electricity in a solution. This is because they dissociate into ions, such as H+ and anions, which can carry electrical charge.b. They have a pH above 9.: This is actually characteristic of bases, not acids. Bases have a pH above 7, with a higher pH indicating a stronger base.d. They have a strong affinity for H ions.: This statement is somewhat misleading. Acids do release H+ ions, but they don't have a strong affinity for them. Instead, acids tend to donate H+ ions, increasing their concentration in a solution.What is the mass of 2.45 miles or C3H403?
Answer:
215.6 g.
Explanation:
We have the relation:no. of moles (n) = mass/molar mass.
∴ mass of C₃H₄O₃ = (no. of moles)*(molar mass) = (2.45 mol)(88.0 g/mol) = 215.6 g.
How many kJ of energy will be released when 4.72g of carbon react with excess oxygen to produce carbon dioxide (delta H is -393.5 kJ)
Answer:
155 kJ of energy will be released.
Explanation:
The [tex]\rm \Delta H\textdegree[/tex] ([tex]\rm \Delta H \textdegree_\text{rxn}[/tex] in some textbooks) here stands for standard enthalpy change per mole reaction. To find the amount of energy released in this reaction, start by finding the number of moles of this reaction that will take place.
How many moles of atoms in 4.72 grams of carbon?
Relative atomic mass data from a modern periodic table:
C: 12.01.[tex]\displaystyle n = \frac{m}{M} = \rm \frac{4.72\;g}{12.01\; g\cdot mol^{-1}} = 0.393006\; mol[/tex].
The coefficient of carbon in the equation is one. In other words, each mole of the reaction will consume one mole of carbon. Oxygen is in excess. As a result, [tex]\rm 0.393006\; mol[/tex] of carbon will support [tex]\rm 0.393006\; mol[/tex] of the reaction.
How much energy will be released?
The [tex]\rm \Delta H\textdegree{}[/tex] value here is negative. But don't panic. [tex]\rm \Delta H\textdegree{}[/tex] is the same as the chemical potential energy of the reactants minus the products in one mole of the reaction. [tex]\rm \Delta H\textdegree{} = -393.5\;kJ[/tex] means that the chemical potential energy drops by [tex]\rm 393.5\; kJ[/tex] during each mole of the reaction (with the coefficients as-is.) Those energy difference will be released as heat. In other words, one mole of the reaction will release [tex]\rm 393.5\;kJ[/tex] of energy.
The 4.72 grams of carbon will support [tex]\rm 0.393006\; mol[/tex] of this reaction. How much heat will that [tex]\rm 0.393006\; mol[/tex] of reaction release?
[tex]Q = n \cdot (-\Delta \text{H}\textdegree{}) = \rm 0.393006\times 393.5 = 155\;kJ[/tex].
As a side note, the mass of carbon 4.72 grams is the least significant data in this question. There are three significant figures in this value. As a result, keep more than three significant figures in calculations but round the final result to three significant figures.
The energy released when 4.72g of carbon reacts with excess oxygen to form CO₂ is -154.8 kJ.
To determine how many kJ of energy are released when 4.72g of carbon reacts with excess oxygen to produce carbon dioxide, we use the given enthalpy change (ΔH) for the reaction:
First, we need to find the number of moles of carbon in 4.72g:
Molar mass of carbon = 12 g/mol
Moles of carbon = mass / molar mass = 4.72 g / 12 g/mol = 0.3933 mol
The reaction for the combustion of carbon to form CO₂ is exothermic, with ΔH = -393.5 kJ/mol.
The total energy released is calculated as follows:
Energy released = moles of carbon x ΔH
Energy released = 0.3933 mol x -393.5 kJ/mol = -154.8 kJ
Thus, the energy released when 4.72g of carbon reacts with excess oxygen is -154.8 kJ.
An electron moved from a higher energy level to a lower energy level. What most likely happened during the transition?
Answer: A. A photon was released.
An electron moved from a higher energy level to a lower energy level. What most likely happened during the transition? (5 points)
A. A photon was released.
B. A photon was absorbed.
C. A fixed amount of energy was absorbed.
D. A random amount of energy was released.
Explanation:
I just took the test and A. A photon was released is the correct answer!
Good Luck!!
( P.S.- I just used the other answer on the test and it was incorrect, but this one is correct because I finished the test and got the answer key!)
During the electron's transition from a higher to a lower energy level, it most likely released energy, possibly in the form of light, consistent with Bohr's model of the atom.
Explanation:When an electron moves from a higher energy level to a lower energy level, it most likely emitted energy. This concept is grounded in Bohr's model of the atom where each electron orbit is an energy level with a specific energy value. A transition between these levels involves a change in the electron's energy, corresponding to the energy difference between the levels.
For example, if an electron moves from level 8 to level 1, it descends through several energy levels and, according to Bohr's model, emits energy at each transition. This energy can be quantified, such as in the change of -10.2 eV from a higher to a lower state, releasing 10.2 eV of energy. The emitted energy often manifests as light, with the color depending on the energy change involved.
What is the percent composition of silicon in silicon carbide (SiC)? A. 28% B. 50% C. 70% D. 142%
Hey there!
Here goes your answer ↓
Question :- What is the percent composition of silicon in silicon carbide (SiC)?
A. 28%
B. 50%
C. 70%
D. 142%
Answer :- The percentage of silicon content in silicon carbide (SiC) is option (C) 70%.
Hope it helps you.
Have a great day ahead!
Answer : The correct option is, (C) 70%
Explanation : Given,
Molar mass of Si = 28.09 g/mole
Molar mass of C = 12 g/mole
Molecular mass of SiC = 28.09 + 12 = 40.09 g/mole
To calculate the mass percent of an element in a compound, we use the equation:
[tex]\text{Percent composition of Si}=\frac{\text{Mass of Si in compound}}{\text{Mass of the compound}}\times 100[/tex]
Now put all the given values in above equation, we get:
[tex]\text{Percent composition of Si}=\frac{28.09g}{40.09g}\times 100=70\%[/tex]
Hence, the percentage composition of Si in the given compound is 70%