Urban development has been linked to many environmental problems, including air pollution, water pollution, and loss of wildlife habitat. Urban runoff often contains nutrients, sediment and toxic contaminants, and can cause not only water pollution but also large variation in stream flow and temperatures.
You are given a stock solution of 500.0 mL of 1.00M magnesium chloride solution. Calculate the volume of the stock solution you would need to use to prepare 250.0 mL of 0.20 M solution.
Answer:
[tex]50\; \rm mL[/tex] of the stock solution would be required.
Explanation:
Assume that a solution of volume [tex]V[/tex] contains a solute with a concentration of [tex]c[/tex]. The quantity [tex]n[/tex] of that solute in this solution would be:
[tex]n = c \cdot V[/tex].
For the solution that needs to be prepared, [tex]c = 0.20\; \rm M = 0.20\; \rm mol \cdot L^{-1}[/tex]. The volume of this solution is [tex]V = 250.0\; \rm mL[/tex]. Calculate the quantity of the solute (magnesium chloride) in the required solution:
[tex]\begin{aligned}n &= c \cdot V \\ &= 0.20\; \rm mol \cdot L^{-1} \times 250.0\; \rm mL \\ &= 0.20\; \rm mol \cdot L^{-1} \times 0.2500\; \rm L \\ &= 0.050\; \rm mol\end{aligned}[/tex].
Rearrange the equation [tex]n = c \cdot V[/tex] to find an expression of volume [tex]V[/tex], given the concentration [tex]c[/tex] and quantity [tex]n[/tex] of the solute:
[tex]\displaystyle V= \frac{n}{c}[/tex].
Concentration of the solute in the stock solution: [tex]c(\text{stock}) = 1.00\; \rm M = 1.00\; \rm mol \cdot L^{-1}[/tex].
Quantity of the solute required: [tex]n = 0.050\; \rm mol[/tex].
Calculate the volume of the stock solution that would contain the required [tex]n = 0.050\; \rm mol[/tex] of the magnesium chloride solute:
[tex]\begin{aligned}& V(\text{stock}) \\ &= \frac{n}{c(\text{stock})} \\ &= \frac{0.050\; \rm mol}{1.00\; \rm mol \cdot L^{-1}} \\ &= 0.050\; \rm L \\ &= 50\; \rm mL\end{aligned}[/tex].
Molecular geometry of AX2E
Answer:
This molecule is made up of 3 equally spaced sp2 hybrid orbitals arranged at approximately 120o angles. The shape of the orbitals is planar triangular. One orbital contains a lone pair of electrons.
4NH3(g) + 6NO(g)→5N2(g) + 6H2O(g) Using the balanced equation calculate the mass of N2 produced from 100 grams of NH3 racing with an unlimited supply of NO.
Here's link to the answer:
bit.[tex]^{}[/tex]ly/3a8Nt8n
Three facts about Dalton’s Model of the Atom:
Explanation:
Everything is composed of atoms, which are the indivisible building blocks of matter and cannot be destroyed. All atoms of an element are identical. The atoms of different elements vary in size and mass. Compounds are produced through different whole-number combinations of atoms.
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32. Explain why carbon shows versatile nature why it forms so many organic compounds.
Answer:
Carbon is a versatile element and is found in many different chemical compounds, including those found in space. Carbon is versatile because it can form single, double, and triple bonds. It can also form chains, branched chains, and rings when connected to other carbon atoms.
Explanation:
meaning of versatile: capable of or adapted for many different uses, skills, etc. 2 variable or changeable.
The versatile nature of carbon can be best understood with its features such as, tetravalency and catenation. In this section let us learn more about versatility of carbon.
Carbon is a versatile element and is found in many different chemical compounds, including those found in space. Carbon is versatile because it can form single, double, and triple bonds. It can also form chains, branched chains, and rings when connected to other carbon atoms.
The two characteristic features seen in carbon, that is, tetravalency and catenation, put together give rise to a large number of compounds. Many have the same non-carbon atom or group of atoms attached to different carbon chains.
Catenation: The property of forming long chains by self-linking with other carbon atoms to form long chains, rings, double or triple bonds is called catenation.
Isomerism: Compounds with same molecular formula but different structural formula are called isomers. An isomerism commonly seen is due to difference in the arrangement of atoms or groups of atoms & is called structural isomerism. The 4 types of structural isomerism are:
Chain isomerism
Position
Functional
Metamerism
Tetravalency: Carbon has 4 electrons in its valence shell. Energy considerations do not allow it to gain or lose 4 electrons; therefore it forms covalent bonds with other elements to complete its octet. This accounts for its tetravalency and explains its ability to form a variety of compounds.
Michell saw a model of a skeleton in a science store. She counted the bones in the skeleton. There were 206. Which is NOT something the 206 bones in our skeletons do?
A. support the body
B. help the body move.
C. regulate temperature.
D. protect internal organ
Help me!!!
Answer:
C, regulate temperature
Explanation:
Bones take no part in temperature regulation throughout the body.
If you traveled 25 meters in 100 seconds, what is your speed?
.25 meters per second
25/100
.25
100/100
1
the volume of alcohol present in 409ml of 11%
Answer:
Amount of Alcohol volume present in solution = 44.99 ml
Explanation:
Given:
Total volume of solution = 409 ml
Amount of Alcohol percentage present in solution = 11%
Find:
Amount of Alcohol volume present in solution
Computation:
Amount of Alcohol volume present in solution = Total volume of solution x Amount of Alcohol percentage present in solution
Amount of Alcohol volume present in solution = 409 x 11%
Amount of Alcohol volume present in solution = 409 x 0.11
Amount of Alcohol volume present in solution = 44.99 ml
What is the correct formula for the compound made of magnesium and nitrogen
Answer:
Mg3N2
Explanation:
it has an inorganic compound for Magnesium and Nitrogen. if you put this two together it will the compound Magnesium nitride.
10 examples of salt in chemistry
Answer:
nacl cacl kcl mgcl k2so4 na2co3 na2so4 kno3 nahco3 naco3
Explanation:
Find the number of moles in 1.00 x 1023 atoms of chromium.
Answer:
0.17 molesExplanation:
To find the number of moles in a substance given it's number of entities we use the formula
[tex]n = \frac{N}{L} \\[/tex]
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
We have
[tex]n = \frac{1.00 \times {10}^{23} }{6.02 \times {10}^{23} } = \frac{1}{6.02} \\ = 0.166112[/tex]
We have the final answer as
0.17 molesHope this helps you
Which is the reactant - and why?
Explanation:
The substance(s) to the left of the arrow in a chemical equation are called reactants. A reactant is a substance that is present at the start of a chemical reaction. The substance(s) to the right of the arrow are called products . A product is a substance that is present at the end of a chemical reaction
Convert 25 g CO2 to moles CO2
3. Look at the reaction below:
H2O + C —— CO+ H2
AH = +130kJ mol^-1
Explain what happens to the position of equilibrium if we:
a. increase the pressure
b. increase the concentration of hydrogen gas
c. increase the temperature
d. add a catalyst
Explanation:
a. pressure always favors the side with fewer molecules. in this reaction as both the sides have equal number of molecules, there won't be any change in the position of the equilibrium.
b. when the concentration of the hydrogen gas is increased. more particles would take place in the reaction and so, the rate of reaction would increase favoring the reaction concerning hydrogen gas molecules (backward reaction in this case) therefore, equilibrium would shift to the backward reaction (left).
c. as forward reaction is endothermic, when temperature is increased the equilibrium will shift to the forward reaction (right).
d. catalyst would not have any effect on the position of the equilibrium. it will only increase the rate of reaction.
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What is an energy conserved system ?
Answer: In physics and chemistry, the law of conservation of energy states that the total energy of an isolated system remains constant; it is said to be conserved over time. For instance, chemical energy is converted to kinetic energy when a stick of dynamite explodes.
Explanation:
internet
Solution (a) has a hydrogen ion concentration of 2.7 x 10^-3 and solution (b) has a hydrogen ion concentration of 4.1 M. What are their pH and say if they are acids or bases.
Answer: a) pH = 2.56 , acidic
b) pH = 2.38, acidic
Explanation:
pH or pOH is the measure of acidity or alkalinity of a solution.
pH is calculated by taking negative logarithm of hydrogen ion concentration.
[tex]pH=-\log [H^+][/tex]
a) [tex][H^+]=2.7\times 10^{-3}[/tex]
Putting in the values:
[tex]pH=-\log[2.7\times 10^{-3}][/tex]
[tex]pH=2.56[/tex]
Thus as pH is less than 7, the solution is acidic.
b) [tex][H^+]=4.1\times 10^{-3}[/tex]
Putting in the values:
[tex]pH=-\log[4.1\times 10^{-3}][/tex]
[tex]pH=2.38[/tex]
Thus as pH is less than 7, the solution is acidic.
12 Mixture 1 contains sand and water
Mixture 2 contains salt and water
Which method of separation could be used to obtain each of the required products from each
mixture?
mixture 2
10 ottain sand
to obtam water
to obtain salt
to obtain water
crystalisation
distillation
filtration
fiftration
B
crystalisation
filtration
fitration
distillation
Ty tallation
Crystallisation
Answer:
B i tyink
Explanation:
brainlyest plssss
To obtain sand and water from mixture 1 , filtration process will be used.
To obtain salt from water in mixture 2 , crystallisation will be done.
What is physical treatment process?Physical wastewater treatment processes include use of racks, screens, clarifiers (sedimentation and flotation), and filtration. Chemical or biological reactions are important treatment processes, but not part of a physical treatment process.
It is given that the mixture contains
Mixture 1 contains sand and water
Mixture 2 contains salt and water
To obtain sand and water from mixture 1 , filtration process will be used.
To obtain salt from water in mixture 2 , crystallisation will be done.
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If 5.0 g of copper metal reacts with a solution of silver nitrate, how many grams of silver metal are recovered?
Cu + Ag(NO3)2=Cu(NO3)2 + Ag
Answer:
16.9g
Explanation:Cu+2AgNO3→2Ag+Cu(NO3)2
Cu will likely have a +2 oxidation state. It is higher in the activity series than Ag, so it is a stronger reducing agent and will reduce Ag in a displacement reaction. Then you need to balance the coefficients knowing than NO3 is -1 and Ag is +1.
Then to calculate the theoretical yield you need to compare moles of the reactants:
m(Cu)=5g
M(Cu)=63.55
n(Cu)=5/63.55=0.0787
By comparing coefficients you require twice as much silver: 0.157mol
n(Ag)=0.157
M(Ag)=107.86
m(Ag)=0.157x107.86=16.9g
Hence, the theoretical yield of this reaction would be 16.9g
The table shows four solutions that were prepared by
dissolving salt in water.
Solution
Mass of NaCl Volume of Water
(g)
(mL)
A
5.0
50.0
B
5.0
75.0
С
5.0
100.0
D
5.0
125.0
Which of the solutions has the highest salt
concentration?
O A. Solution B
OB. Solution D
O C. Solution C
O D. Solution A
Answer:
a
Explanation:
The solution that has the highest concentration given the data is solution A ( Option D)
What is molarity?This is defined as the mole of solute per unit litre of solution. Mathematically, it can be expressed as:
Molarity = mole / Volume
How to determine the mole of NaCl Mass of solute = 5 g Molar mass of NaCl = 58.5 g/mol Mole of NaCl =?Mole = mass / molar mass
Mole of NaCl = 5 / 58.5
Mole of NaCl = 0.085 mole
How to determine the molarity of solution AMole of NaCl = 0.085 mole Volume = 50 mL = 50 / 1000 = 0.05 L Molarity of solution A =?Molarity = mole / Volume
Molarity of solution A = 0.085 / 0.05
Molarity of solution A = 1.7 M
How to determine the molarity of solution BMole of NaCl = 0.085 mole Volume = 75 mL = 75 / 1000 = 0.075 L Molarity of solution B =?Molarity = mole / Volume
Molarity of solution B = 0.085 / 0.075
Molarity of solution B = 1.13 M
How to determine the molarity of solution CMole of NaCl = 0.085 mole Volume = 100 mL = 100 / 1000 = 0.1 L Molarity of solution C =?Molarity = mole / Volume
Molarity of solution C = 0.085 / 0.1
Molarity of solution C = 0.85 M
How to determine the molarity of solution DMole of NaCl = 0.085 mole Volume = 125 mL = 125 / 1000 = 0.125 L Molarity of solution D =?Molarity = mole / Volume
Molarity of solution D = 0.085 / 0.125
Molarity of solution D = 0.68 M
SUMMARY
Molarity of solution A = 1.7 MMolarity of solution B = 1.13 MMolarity of solution C = 0.85 MMolarity of solution D = 0.68 MThus, solution A has the highest concentration of the salt.
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If a young girl learned that it would be 0° C, or 32° F, the next
day then what kind of weather should she expect?
Answer:
Cold
Explanation:
Because 0°C And below or 32°F Refers To Cold Weather
Michelle learns in science class that simple machines such as an inclined plane can change the amount of force needed to lift heavy objects. She decides to test this with an experiment.
Michelle chooses a 10 kg weight. She sets up a ramp made of smooth metal that makes an angle θ with the floor. She attaches a spring scale to the weight and the top of the ramp in order to hold the weight in place. She records the force from the spring scale, then changes θ and records it again. She repeats this several times.
In this experiment, what is the outcome variable (dependent variable)?
A.
the angle θ between the ramp and the ground
B.
the mass of the weight
C.
the material the ramp is made of
D.
the amount of force on the spring scale
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IF YOU POST ANY LINKS THAT ARE PERM-BLOCKED, I WILL REPORT YOU, TAKE YOUR POINTS AWAY, DELETE YOUR ANSWER, AND PROBABLY BAN YOU! IF YOU DO NOT KNOW, DON'T ANSWER!!!!!!!
Answer: the amount of force on the spring scale
Explanation:
Is the formation of CO2(g) from its elements endothermic or exothermic?
Exothermic because the ΔH is negative.
Endothermic because the ΔH is negative.
Endothermic because the ΔH is positive.
Exothermic because the ΔH is positive.
12. Label Each part of the atom:
Answer:
Atom Labeling
Explanation:
Y- neutron
Z-protron
X - electron
W- nucleus
Lance wants to separate out the salt from a solution of salt water how can he do this
*☆*――*☆*――*☆*――*☆*――*☆*――*☆*――*☆*――*☆**☆*――*☆*――*☆*――*☆
Answer: Boiling the water
I hope this helped!
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d. 2 5. How many moles of HCl are needed to produce 25 moles of KCl in the presence of excess potassium permanganate? a. 16 b. 32 c. 5 d. 200
Answer:
d. 200.
Explanation:
The reaction is:
2KMnO4 + 16HCl ----> 2KCl + 2MnCl2 + 8H2O + 5Cl2
So 2 moles of KCL are produced form 16 moles of HCL
So 25 moles KCL are made from 25 * (16/2) HCl.
= 25 * 8
= 200 moles. HCl.
. What is the OH- concentration of a neutral solution?
A neutral solution is one that is neither acidic nor basic. The hydrogen ion concentration equals the hydroxide ion concentration, and both equal 1 X 10-7 M. In a neutral solution, then, pH = pOH = 7.
2. Which answer is NOT the definition for one of these terms: volcano,
lava, magma?
O a crack or fracture in the Earth's crust where movement occurs
molten rock stored beneath Earth's surface
magma that erupts on Earth's surface
vents in Earth's crust through which molten rock flows
Thermal energy added to a substance that is not changing state causes the substance’s temperature to
Group of answer choices
decrease.
increase
remain unchanged
vary unpredictably
Answer:
increase
Explanation:
Conduction involves the transfer of electric charge or thermal energy due to the movement of particles. When the conduction relates to electric charge, it is known as electrical conduction while when it relates to thermal energy, it is known as heat conduction. Conductors include metal, steel, aluminum, copper, frying pan, pot, spoon etc.
In the process of heat conduction, thermal energy is usually transferred from fast moving particles to slow moving particles during the collision of these particles. Also, thermal energy is typically transferred between objects that has different degrees of temperature and materials (particles) that are directly in contact with each other but differ in their ability to accept or give up electrons.
Hence, thermal energy added to a substance that is not changing state causes the substance’s temperature to increase because it would absorb energy in the form of heat.
what do molecules and elements have in common
Answer:
They both are made up of atoms and having bonds linking their atoms together.molecules and compounds also share the qualities of being both pure and homogeneous substances.
Explanation:
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Rank the following elements by decreasing metallic character: Cesium (C's), Bromine (Br), Osmium (Os), Tin (Sn)
Answer:
Cs, Os, Sn, Br
Explanation:
Metallic character increases to the left and down the periodic table.