When a material gains thermal energy and melts, it is undergoing a physical change.
Answer:
True, it undergoes a physical change.
Explanation:
A physical change is a change that does not change the chemical makeup of a material. This includes altering its shape.
2. Calculate the number of grams of potassium iodide (KI), needed to prepare 500.0 mL of a
0.125 M KI. Show your work.
Answer:
10.38 g
Explanation:
From the question given above, the following data were obtained:
Volume of solution = 500 mL
Molarity of KI solution = 0.125 M
Mass of KI needed =?
Next, we shall convert 500 mL to litres (L). This can be obtained as follow:
1000 mL = 1 L
Therefore,
500 mL = 500 mL × 1 L / 1000 mL
500 mL = 0.5 L
Thus, 500 mL is equivalent to 0.5 L.
Next, we shall determine the number of mole KI in the solution. This can be obtained as illustrated below:
Volume of solution = 0.5 L
Molarity of KI solution = 0.125 M
Mole of KI =?
Molarity = mole /Volume
0.125 = mole of KI /0.5
Cross multiply
Mole of KI = 0.125 × 0.5
Mole of KI = 0.0625 mole
Finall, we shall determine the mass of KI needed to prepare the solution as follow:
Mole of KI = 0.0625 mole
Molar mass of KI = 39 + 127 = 166 g/mol
Mass of KI =?
Mole = mass /Molar mass
0.0625 = mass of KI /166
Cross multiply
Mass of KI = 0.0625 × 166
Mass of KI = 10.38 g
Therefore, 10.38 g is needed to prepare the solution.
For the preparation of 0.125 M of KI solution, 10.37 grams of KI is needed.
Molarity can be defined as the moles of solute in a liter of solution.
Molarity = [tex]\rm \dfrac{weight}{molecular\;weight}\;\times\;\dfrac{1000}{volume\;(ml)}[/tex]
Given, Molarity = 0.125 M
volume = 500 ml
We know the molecular weight of KI = 166.002 g/mol
Putting the values in the equation:
0.125 M = [tex]\rm \dfrac{weight}{166.002}\;\times\;\dfrac{1000}{500}[/tex]
weight = [tex]\rm \dfrac{0.125\;\times\;166.002}{2}[/tex]
weight of KI = 10.37 grams.
For the preparation of 0.125 M of KI solution, 10.37 grams of KI is needed.
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Zn + (
)HCl → (
)ZnCl2 + (
)H2
All the following are physical properties of metals EXCEPT
a. malleability
c. conductivity
b. brittleness
d. ductility
Explanation:I think it's option b) brittleness
I hope this might help u
Analysis of the water content of a lake found in the desert showed that it contained 17.5 percent chloride ion, and has a density of 1.23 g/mL. What is the molarity of the chloride ion in the water
Answer:
The molarity is 6.0 M.
Explanation:
The concentration of a solution is the amount of solute present in a given amount of solvent, or a given amount of solution.
In this problem, we are asked to convert percent by mass to molarity, which are two different concentration units.
The percent by mass is the ratio of the mass of a solute to the mass of the solution, multiplied by 100 percent. On the other hand, molarity (M) is defined as the number of moles of solute per liter of solution.
If we have 17.15 percent chloride ion, that means that we have 17.15 grams of chloride ion in 100 grams of solution. The density provided is the density of the solution, so we calculate how many mL correspond to 100 grams of solution:
1.23 g ----------- 1 mL
100 g ------------ x= 81.3 mL
Therefore, 17.5 grams of chloride ion are contained in 81.3 mL. Now we need to convert these grams into moles.
The atomic mass of chlorine is 35.5 g/mol:
35.5 g --------------- 1 mol
17.5 g --------------- x= 0. 49 mol
This 0.49 moles are contained in 81.13 mL, the definition of molarity says that this moles are contained in a liter (or what is the same, 1000 mL):
81.3 mL --------------- 0.49 mol
1000 mL ------------- x= 6.0 M
The molarity of the chloride ion will be 6.0 M.
What is the concentration of silver ions in a saturated solution of Ag3PO4? Ksp (Ag3PO4) = 8.9 x 10−17.
Answer:
4.3x10⁻⁵ mol/L.
Explanation:
Hello there!
In this case, since the dissolution of silver phosphate is not completely achieved due to its low solubility in water, we can represent this as an equilibrium problem by which it separates into silver and phosphate ions:
[tex]Ag_3PO_4(s)\rightleftharpoons 3Ag^+(aq)+PO_4^{3-}(aq)[/tex]
Which are slightly soluble in water; it means that the equilibrium expression is:
[tex]Ksp=[Ag^+]^3[PO_4^{3-}][/tex]
Thus, since we know the solubility product and the concentration of these ions in a saturated solution is represented by the reaction extent [tex]x[/tex], we can write:
[tex]8.9x10^{-17}=(3x)^3(x)[/tex]
Thus, solving for [tex]x[/tex] we obtain:
[tex]x=\sqrt[4]{\frac{8.9x10^{-17}}{27} } \\\\x=4.3x10^{-5}M[/tex]
Thus, the molar concentration of silver ions is 4.3x10⁻⁵ mol/L.
Best regards!
how do organisms
can compete for abiotic
factors in an ecosystem.
Answer:
An organism's niche includes food, shelter, its predators, the temperature, the amount of moisture the organism needs to survive, etc. When two or more individuals or populations try to use the same limited resources such as food, water, shelter, space, or sunlight, it is called competition.
Why do gases diffuse more quickly than liquids?
Choose the correct answer.
A) Liquids can be compressed easily.
B)The particles in gases are not mobile.
C)Liquids are always at lower temperatures than gases.
D)Gas particles move rapidly and have space between them.
Answer:
D)Gas particles move rapidly and have space between them.
Explanation:
Matter exists in three states namely: solids, liquids and gases. The particles contained in these three states are different from one another. In the gaseous state, the particles are FAR APART from one another i.e. space exists and they move at a very fast rate in contrast to the particles of a liquid, which have less space and move slower.
This rapid movement of gas particles within a less restricted space accounts for the reason why gaseous substances DIFFUSE more quickly than liquids.
please tell me which one?
Answer:
i think its c
Explanation:
1 point
Which element requires the least amount of energy to remove its valence electron(s)?
barium
chlorine
oxygen
carbon
what elements make up duralumin( an alloy)?
Answer:
In addition to aluminium, the main materials in duralumin are copper, manganese and magnesium.
Answer:
The original composition has been varied for particular applications; it may contain about 4 percent copper, 0.5–1 percent manganese, 0.5–1.5 percent magnesium, and, in some formulations, some silicon.
A beverage manufacturer wants to increase The solunility of carbon dioxide in its carbonated drinks as beverages produced which action will increase the solubility of CO2 gas the most
A. Decreasing the pressure on it
B. Increasing stirring
C. Decreasing its temperature
D. Increasing its temperature
Answer: C
Explanation:
НО-ОН
what is the reaction to show the bond cleavage
Answer:
Fast and slow free-radical recombination reactions in thermal breakdown. As thermally induced bond-cleavage reactions and the depolymerisation of coals accelerate above 350–375°C, the more reactive of the free radicals have greater potential to undergo either retrogressive or quenching (cappin
Explanation:
25. Which of the following statements concerning atomic structure is/are correct?
1. The nucleus contains most of an atom's mass.
2. The nucleus contains all the positive charge of an atom.
3. Electrons surround the nucleus and account for the majority of an atom's volume.
1 only
2 only
3 only
2 and 3
1, 2, and 3
Answer:
It would be 2 and 3
The image shows the structure of an atom, I hope it helps :)
To see the number of atoms of an element in a given molecule we need to multiply stoichiometry to the number that is written on the foot of the element that is stoichiometry. Therefore, the correct option is option 2,3.
What is atom?Atom is the smallest particle of any element, molecule or compound. Atom can not be further divided. Atoms contains nucleus in its center and electron that revolve around the atom in fixed orbit.
In the nucleus, proton and neutron are present. Electron has -1 charge while proton has +1 charge. Neutron is neutral that is it has no charge. So overall the charge of nucleus is due to only proton, not by neutron. The nucleus contains all the positive charge of an atom. Electrons surround the nucleus and account for the majority of an atom's volume.
Therefore, the correct option is option 2,3.
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A wiffle is a unit of measurement related to distance. Scientists who study coral reefs use a wiffle ball to measure the size of the coral reef. One wiffle is equal to 3.5 inches. Convert 25 wiffles into inches.
Answer:
87.5inches
Explanation:
Given parameters;
Convert 25 wiffles to inches
1 wiffle = 3.5 inches
25 wiffles = 25 x 3.5 = 87.5inches
25 wiffles is the same as 87.5inches
Even though the molecular formula of acetylene is C2H2, and that of benzene is C6H6, these compounds have the same percent composition and therefore the same empirical formula. What is their empirical formula?
Answer:
CH
Explanation:
The empirical formular is the simplest formular of a compound. It shows the relative number of elements present in a compounds. It shows the number of atoms of elements present in simple ratios.
In both compounds, the ratio of the carbon to hydrogen s 1:1
In C2H2;
C : H = 2 : 2 (Which is equivalent to 1 : 1)
In C6H6;
C : H = 6 : 6 (Which is equivalent to 1 : 1)
This means the empirical formular is CH
Calculate the volume of a liquid with a density of 5.45 g/mL and a mass of 65 g.
Answer:
The answer is 11.93 mLExplanation:
The volume of a substance when given the density and mass can be found by using the formula
[tex]volume = \frac{mass}{density} \\ [/tex]
From the question we have
[tex]volume = \frac{65}{5.45} \\ = 11.926605...[/tex]
We have the final answer as
11.93 mLHope this helps you
formal charge of hcooh
Answer:
What is the question?
Does water take up space (have volume)? Yes or no
Answer:
Yes
Explanation:
A mystery element "X” has two stable isotopes X-50 which occurs 40% of the time
and X-60 which occurs 60% of the time. What is the average mass of element "X"?
A-50 amu
B-54 amu
C-56 amu
D-60 amu
Answer:
probaly C
Explanation:
I'm not sure on this one...
TRUE OR FALSE? Alloys are used more than pure metals because they are generally softer and less likely to react with air or water.
Alloys are used much more than pure metals because they are generally stronger and less likely to react with air or water...
So I would say false
What total volume of ozone measured at a pressure of 24.5 mmHg and a temperature of 232 K can be destroyed when all of the chlorine from 15.5 g of CF3Cl goes through 10 cycles of these reactions
Answer:
[tex]1.75272\ \text{m}^3[/tex]
Explanation:
The breakdown reaction of ozone is as follows
[tex]CF_3Cl + UV \rightarrow CF_3 + Cl[/tex]
[tex]Cl + O_3 \rightarrow ClO + O_2[/tex]
[tex]O_3 + UV \rightarrow O_2 + O[/tex]
[tex]ClO + O \rightarrow Cl + O_2[/tex]
It can be seen that 2 moles of ozone is required in the complete cycle
So for 10 cycles, 20 moles of ozone is required
m = Mass of [tex]CF_3Cl[/tex] = 15.5 g
M = Molar mass of [tex]CF_3Cl[/tex] = 104.46 g/mol
P = Pressure = 24.5 mmHg
T = Temperature = 232 K
R = Gas constant = [tex]62.363\ \text{L mmHg/K mol}[/tex]
Number of moles is given by
[tex]n=\dfrac{m}{M}\\\Rightarrow n=\dfrac{15.5}{104.46}\\\Rightarrow n=0.1484\ \text{moles}[/tex]
[tex]20\ \text{moles} = 20\times 0.1484 = 2.968\ \text{moles}[/tex]
From ideal gas law we have
[tex]PV=nRT\\\Rightarrow V=\dfrac{nRT}{P}\\\Rightarrow V=\dfrac{2.968\times 62.363\times 232}{24.5}\\\Rightarrow V=1752.72\ \text{L}=1.75272\ \text{m}^3[/tex]
For 20 cycles of the reaction the volume of the ozone is [tex]1.75272\ \text{m}^3[/tex].
The Total volume of Ozone measured is = 1.7527 m³
Given data :
Mass of CF₃Cl = 15.5 g
Molar mass of CF₃Cl = 104.46 g/mol
Pressure ( P ) = 24.5 mmHg
T = 232 K
Gas constant ( R ) = 62.363 L mmHg/K mol
Note : For a complete ozone cycle 2 moles of ozone is required therefore for 10 cycles 20 moles of ozone will be required
First step : Determine number of moles in each cycle reaction
n = m / M ----- ( 1 )
m = mass = 15.5 g
M = molar mass = 104.46 g/mol
∴ n = 15.5 / 104.46 = 0.1484
Hence the number of moles in 10 cycle = 20 * 0.1484 = 2.968 moles
Next step : Apply Ideal gas law to determine the volume of Ozone
PV = nRT ----- ( 2 )
n = 2.968
V = ?
R = 62.363 L mmHg/K mol
T = 232 K
P = 24.5 mmHg
∴ V = nRT / P --- ( 3 )
= ( 2.968 * 62.363 * 232 ) / 24.5
= 1752.72 L ≈ 1.7527 m³
Hence we can conclude that the Total volume of Ozone measured is = 1.7527 m³
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Calculate the molarity of 32.9 g32.9 g of MgS MgS in 971 mL 971 mL of solution.
Answer:
0.60 M
Explanation:
Given data:
Mass of MgS = 32.9 g
Volume of solution = 971 mL (0.971 L)
Solution:
Molarity is used to describe the concentration of solution. It tells how many moles are dissolve in per litter of solution.
Formula:
Molarity = number of moles of solute / L of solution
Number of moles of MgS:
Number of moles = mass/molar mass
Number of moles = 32.9 g/ 56.38 g/mol
Number of moles = 0.58 mol
Molarity of solution:
M = 0.58 mol/ 0.971L
M = 0.60 M
The diagram above shows a simple electric circuit. Which of the following statements describes the function of the battery?
a. It reduces the flowlof electrons
b. It transmits light through the circuit It pushes electrons
c. through the circuit
d. It releases light during a chemical reaction
In the electronic circuit, the function of battery is to push the electrons through the circuit.
What is electronic circuit?
An electronic circuit comprises of individual electronic components like resistors, diodes,transistors , capacitors,etc. which are connected to each other by means of wires through which electric current flows.It can also be referred to as an electronic circuit.
It usually comprises of at least one active component . The combination of wires and simple and complex components allows operations to be performed, amplification of signals, displacement of data and performing of computations.
There are three types of circuits , an analog circuit ,a digital circuit and a mixed circuit which is combination of digital and analog circuits , even semiconductors are used in circuits.
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A scientist who collects and analyzes DNA from a crime scene is a
Answer:
forensic scientist
Explanation:
forensic science is the discipline in which professionals use scientific means to analyze physical crime evidence. this evidence is then presented in court in order to help determine the innocence or guilt of a specific suspect.
Answer:
Its a forensic scientist :D
Explanation:
I took a test and got it wrong but it showed the right answer and its a forensic scientist
(don't ask how i got it wrong i was rushing!!)
PLEASE HELPPPP
I WILL MARK 1st ONE BRAINLIEST
Answer:
the first one(atoms only give off certain frequencies)
Explanation:
PLEASE HELP IM TIMED
Which of the following is not an oxidation-reduction reaction?
Upper X e upper F subscript 6 (s) right arrow upper X e upper F subscript 4 (s) plus upper F subscript 2 (g).
2 upper C s (s) plus upper I subscript 2 (g) right arrow 2 upper C s upper I (s).
2 upper H subscript 2 upper S upper O subscript 4 (a q) plus 2 upper B a (upper O upper H) subscript 2 (a q) right arrow 2 upper B a upper S upper O subscript 4 upper H subscript 2 upper O (l).
Upper Z n (s) lus 2 upper A g upper N upper O subscript 3 (a q) right arrow upper Z n (upper N upper O subscript 3) subscript 2 (a q) plus upper A g (s).
Answer: choice 2
Explanation:
PLEASE HELP ME! I am confused on this.
Answer:
Mohammed has less kinetic energy
Explanation:
m=Kg
V= m/s
KE= kinetic energy = J
the way you work out the answer is:
KE = 1/2 × m × v squared
What volume. In liters, of H2O(g) measured at STP is produced by the combustion of 15.63 g of natural gas (CH4) according to the following equation? CHale) +20269) CO2 + 2H2008)
Answer:
V = 43.95 L
Explanation:
Given data:
Mass of CH₄ decomposed = 15.63 g
Volume of H₂O produced at STP = ?
Solution:
Chemical equation:
CH₄ + 2O₂ → 2H₂O + CO₂
Number of moles of CH₄:
Number of moles = mass/molar mass
Number of moles = 15.63 g/ 16 g/mol
Number of moles = 0.98 mol
Now we will compare the moles of H₂O with CH₄.
CH₄ : H₂O
1 : 2
0.98 : 2×0.98 = 1.96 mol
Volume of hydrogen:
PV = nRT
1 atm × V = 1.96 mol × 0.0821 atm.L/mol.K × 273.15 K
V = 43.95atm.L / 1atm
V = 43.95 L
Unless otherwise instructed, you may use the periodic table in the Chemistry: Problems and Solutions book for this question.
Which explanation accounts for why carbon monoxide is not a polar molecule?
The electronegativity differences between carbon and oxygen are not very large.
Carbon and oxygen do not form ions.
Carbon is a metal, and oxygen is a nonmetal.
There are no hydrogen atoms in the molecule.
The statement 'the electronegativity differences between carbon and oxygen are not very large' accounts for why carbon monoxide is not a polar molecule.
What is a polar molecule?A polar molecule is a molecule that has a positive pole and a negative pole as a consequence of electronegativity differences.
These differences in electronegativity are due to distinct levels in which atoms attract electrons.
In conclusion, the statement 'the electronegativity differences between carbon and oxygen are not very large' accounts for why carbon monoxide is not a polar molecule.
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