Answer:
The concentration for 25 mL is 0.81 M
Explanation:
Given data:
Initial volume = 135 mL
Initial molarity = 0.150 M
New volume added = 25 mL
Concentration for 25 mL = ?
Solution:
M₁V₁ = M₂V₂
0.150 M × 135 mL = M₂ × 25 mL
M₂ = 0.150 M × 135 mL / 25 mL
M₂ = 20.25 M.mL/25 mL
M₂ = 0.81 M
The concentration for 25 mL is 0.81 M.
Elements in the same period have _____ in common?
-
Answer:
The elements that have the same number of energy levels or the orbitals.
Explanation:
They have he same number -- energy levels
After an afternoon party, a small cooler full of ice is dumped onto the hot ground and melts. If the cooler contained 6.60 kg of ice and the temperature of the ground was 42.5 °C, calculate the energy that is required to melt all the ice at 0 °C. The heat of fusion for water is 80.0 cal/g.
Answer:
The quantity of heat required to melt all the ice at 0°C is 2.21 * 10⁶ J
Explanation:
Latent heat of fusion is the heat absorbed by a unit mass of a given solid at its melting point that completely converts the solid to a liquid at the same temperature. Its unit is Joules/kg or Joules/g.
1 calorie = 4.184 Joules
Therefore , 80.0 cal/g = 80.0 cal/g * 4.184 J/cal = 334.72 J/g
1 g = 0.001 kg; Heat of fusion in J/kg = 334.72 J/g * 1g /0.001 kg = 3.35 * 10⁵ J/kg
Quantity of heat, Q = mass * latent heat of fusion of ice
quantity of heat required = 6.60 kg * 3.35 * 10⁵ J/kg
Quantity of heat required = 2.21 * 10⁶ J
Therefore, the quantity of heat required to melt all the ice at 0°C is 2.21 * 10⁶ J
if you a boy answer this question because............. idk
Answer:
no
Explanation:
A 221 mL cup of whole milk contains about 39 mg of cholesterol. Express the cholesterol concentration of the milk in kilograms per cubic meter (kg/m3)
Answer:
0.1765 Kg / m3
Explanation:
Mass of cholesterol = 39mg
Volume = 221mL
The concentration is given as; Mass/ Volume
Concentration = 39 / 221 = 0.1765 mg /mL
The relationship between mg / mL and Kg / m3 is;
1 mg / mL = 1 Kg / m3
This means that;
0.1765 mg /mL = 0.1765 Kg / m3
When 50.0 mL of 0.400 M Ca(NO3)2 is added to 50.0 mL of 0.800 M NaF, CaF2 precipitates, as shown in the netionic equation below. The initial temperature of both solutions is 23.0°C. Assuming that the reaction goes tocompletion, and that the resulting solution has a mass of 100.00 g and a specific heat of 4.18 J/(g ∙°C), calculatethe final temperature of the solution.Ca2+(aq) + 2 F-(aq) → CaF2(s)∆H°=-11.5 kJ
Answer:
23.55°C
Explanation:
Based on the equation:
Ca²⁺(aq) + 2F⁻(aq) → CaF₂(s) ∆H°=-11.5 kJ
When 1 mole of Ca²⁺ and 2 of F⁻ reacts, 11.5kJ are released.
Thus, we need to find moles of reaction to find the heat released and using:
C = SₓmₓΔT
We can find the final temperature as follows:
Moles of reaction:
0.0500L * (0.400mol / L) = 0.0200moles Ca²⁺ = Moles of reaction
Heat produced is:
0.0200 moles * (11.5kJ / mol) = 0.23kJ
Using:
C = SₓmₓΔT
Where C is heat = 230J
S is specific heat = 4.18J/g
m is mass of solution = 100.00g
And ΔT is change in temperature
230J = 4.18J/gₓ100.00gₓΔT
ΔT = 0.55°C
As initial temperature is 23.0°C
Final temperature = 23.0°C + 0.55°C =
23.55°CThe final temperature of the solution is 23.55°C.
We were given the equation
Ca²⁺(aq) + 2F⁻(aq) → CaF₂(s) ∆H°=-11.5 kJ
This means that 1 mole of Ca²⁺ and 2 of F⁻ reacts to form CaF₂ and 1.5kJ is released.
The formula we need to use is C = SₓmₓΔT
where c is heat, s is specific heat, m is number of mole and ΔT is temperature change.
We need to find the moles of reaction first
Moles of reaction = 0.0500L × (0.400mol / L) = 0.0200moles Ca²⁺
Heat produced = 0.0200 moles ×11.5kJ / mol = 0.23kJ
We can then substitute into the formula
C = SₓmₓΔT
C = 230J
S = 4.18J/g
m = 100.00g
ΔT= ?
230J = 4.18J/gₓ100.00gₓΔT
= 0.55°C
Since the initial temperature is 23.0°C
The Final temperature will be 23.0°C + 0.55°C
=23.55°C
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How can energy from the Sun be used to heat water? What
things will affect how well the sunlight heats water?
Answer:
Water is heated as it travels through flat, glazed panels known as solar collectors, which are normally situated on the roof of the building. The heated water is then stored in an insulated storage tank.
Which of the following statements correctly describes the function of cell parts?
A. The cell membrane determines which type of cell will develop.
B. The nucleus contains all the nutrients that the cell needs.
C. The mitochondria are the power plants of the cell.
D. The genes contain hemoglobin.
The statements correctly describes the function of cell parts is the mitochondria are the power plants of the cell. Therefore, option C is correct.
What do you mean by the mitochondria ?The cytoplasm of a cell contains tiny structures (fluid that surrounds the cell nucleus). The majority of a cell's energy is produced by mitochondria, which also have unique genetic material distinct from that present in the nucleus.
Oxidative phosphorylation, which produces ATP using the energy generated during the oxidation of the food we ingest, is the traditional function of mitochondria.
For the majority of biochemical and physiological activities, including growth, mobility, and equilibrium, ATP is used as the main energy source in turn.
Thus, option C is correct.
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An unknown piece of metal weighing 95.0 g is heated to 98.0°C. It is dropped into 250.0 g of water at 23.0°C. When equilibrium is reached, the temperature of the water and piece of metal is 29.0°C. Determine the specific heat of the metal. Assume the heat capacity of the container, a styrofoam cup, is negligible.
Answer:
[tex]C_{metal}=126.6\frac{J}{g\°C}[/tex]
Explanation:
Hello!
In this case, when two substances at different temperature are put in contact and an equilibrium temperature is attained, we can evidence that the heat lost by the hot substance (metal) is gained by the cold substance (water) and we can write:
[tex]Q_{metal}=-Q_{water}[/tex]
Which can be also written as:
[tex]m_{metal}C_{metal}(T_{EQ}-T_{metal})=-m_{water}C_{water}(T_{EQ}-T_{water})[/tex]
Thus, since we need the specific heat of the metal, we solve for it as shown below:
[tex]C_{metal}=\frac{m_{water}C_{water}(T_{EQ}-T_{water})}{-m_{metal}(T_{EQ}-T_{metal})} \\\\C_{metal}=\frac{250.0g*4.184\frac{J}{g\°C}(29.0\°C-98.0\°C)}{95.0g(29.0\°C-23.0\°C)} \\\\C_{metal}=126.6\frac{J}{g\°C}[/tex]
Best regards.
Total enthalpy of formation of reactants and products, enthalpy of reaction. Cmon goons you’ll be rewarded handsomely
Answer:
am going to work it out
Explanation:
i am going to work it out and then tell you the answer ok
Calculate the concentration of sulfate in a solution made from 65.0 mL of 0.55 M sodium sulfate and 85.0 mL of 1.25 M iron(III) sulfate?
we are given the molarity and the volume of solution. The only issue is that the volume is given in mL instead of L. This issue can be fixed by using the following conversion factor:
a
a
a
a
a
a
a
a
a
a
a
a
a
a
a
a
a
a
a
a
a
1000
m
L
=
1
L
Therefore, if we divide 50mL by 1000mL we will obtain a value of 0.05L.
Next, the equation has to be rearranged to solve for the moles of solute:
Moles of solute = Molarity
×
Liters of solution
Now, multiply 0.360 M by 0.05:
0.360 mol
1 L
×
0.05 L
=
0.018 mol
To obtain the mass of solute, we will need to the molar mass of NaCl, which is 58.44 g/mol:
Finally, multiply the number of moles by 58.44 g/mol
0.018
mol
×
58.44
g
1
mol
Boom, here it is:
1.05
g
A sample of 7.4 L of NH3 gas at 22 ∘C and 735 torr is bubbled into a 0.50-L solution of 0.35 M HCl. Assuming that all the NH3 dissolves and that the volume of the solution remains 0.50 L, calculate the pH of the resulting solution.Kb for Nh3=1.8x10-5
Answer:
pH = 9.11
Explanation:
First, using gas law, we will determine the moles of NH3 bubbled. Then, with moles of HCl we can determine how many NH4⁺ are produced. As last, using H-H equation for bases we can find pOH and pH of the solution:
Moles NH3:
PV = nRT
P = pressure: 743 torr * (1atm / 760torr) = 0.9776atm
V = volume: 7.4L
n = Moles. Our incognite
R = Gas constant: 0.082atmL/molK
T is absolute temperature: 273.15K + 22°C = 295.15K
PV / RT = n
0.9776atm*7.4L / 0.082atmL*295.15K = 0.30 moles of NH3
Moles HCl:
0.50L * (0.35mol / L) = 0.175 moles of HCl
Based on the reaction:
NH3 + HCl → NH4⁺ + Cl⁻
All HCl added is producing NH₄⁺ = 0.175 moles NH₄⁺
Moles NH₃: 0.30moles NH3 - 0.175 moles = 0.125 moles NH₃
H-H equation for bases is:
pOH = pKb + log [BH+] / [B]
Where pKb = -log Kb = 4.74
[BH+] could be taken as moles of NH4+ = 0.175 mol
[B] are moles of NH3 = 0.125 mol
pOH = pKb + log [BH+] / [B]
pOH = 4.74 + log [0.175mol] / [0.125mol]
pOH = 4.89
pH = 14-pOH
pH = 9.11
A person aims for a target with a wooden bow and arrow. The image shows the path of the
arrow to the target.
bow and arrow
target
Answer:
What’s the answer
Explanation:
I neeeddsdd
A drug suspension decomposes by zero-order kinetics with a rate constant of 2 mg mL-1month-1. If the initial concentration is 100 mg mL-1, what is the shelf life (t10%)?
Answer: 5 months
Explanation: Rate Law for a reaction is an equation relating the reaction rate of reactants. It is expressed as:
aA + bB → cC + dD
[tex]r=k[A]^{a}[B]^{b}[/tex]
in which k is the rate constant of the reaction
Zero-order Kinetics is a chemical reaction in which the rate doesn't change with the variations in concentration of the reactants. At this state, it is possible to determine the final concentration by using:
[tex][A]=-kt+[A_{0}][/tex]
Shelf-Life is the time required for 10% of a drug or material to desintegrate: it is the time necessary for A to desintegrate 90% of its original concentration.
Then, the shelf-life for the drug is
[tex][A]=-kt+[A_{0}][/tex]
[tex]90=-2t+100[/tex]
2t = 10
t = 5
Shelf-life for a drug which decomposes by zero-order kinetics with rate constant of 3mgmL^{-1}month^{-1} is 5 months
The shelf life for a drug suspension decomposes by zero-order kinetics with a rate constant of 2 mg mL-1month-1 is 5 months.
How we calculate the shelf life?Shelf life for the zero order reaction will be calculated by using the below equation as:
[A] = -kt + [A₀], where
[A₀] = initial concentration of drug suspension = 100 mg/mL
[A] = Final concentration of drug suspension after 10% decomposition = 100-10 = 90mg/mol
k = rate constant = 2 mg/mL.month
t = shelf lime = to find?
On putting all these values on the above equation we get
90 = -2×t + 100
t = 10/2 = 5 months
Hence, 5 months is the shelf life.
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A reaction of 2.00 ml of nitric acid and excess sodium hydroxide was carried out in
an lae calorimeter. It resulted in a change in volume of the ice/water mixture of
0.217 mL in an Ice calorimeter. The enthalpy of neutralization of nitric acid is -56.3
kJ/mol, density of Ice - 0.917 g/mL, density of water at the 0°C -1.00 g/ml, and
the enthalpy of fusion for ice - 333 J/g. Calculate the molarity of nitric acid.
-1.42 x 10-3M
-4.49 M
-7.09 M
-6.07 x 10-3M
-6.33 x 10-3M
what volume of 3.25m naoh would be required to form 1 mole of na3po4
Answer: 0.923 L
Explanation: The reaction between naoh and h3po4 is:
3naoh + h3po4 —> na3po4 + 3h20
this means it requires 3 mols of naoh to make na3po4
given the concentration, 3.25 M, the equation looks like this:
3.0 mol x (1.0L/ 3.25mol) = 0.923 L
Oxygen gas is made of molecules like the one this model shows. Which
chemical formula most likely describes oxygen gas?
A. OG
B. 00
C. 02
D. 0100
Please help me it due today at 11:00am please help me will mark the brainiest please
The work done to compress a gas is 83.0 J. As a result, 27.0 J of heat is given off to the surroundings. Calculate the change in energy of the gas.
Answer:
ΔU° = 56.0 J
Explanation:
Step 1: Given data
Work done to compress the gas (w): 83.0 J (When work is done on the gas, w is positive).Heat given off to the surroundings (q): -27.0 J (When heat is released to the surroundings, q is negative)Step 2: Calculate the change in the internal energy of the gas (ΔU°)
The internal energy of a gas is the energy contained within it. We can calculate it using the following expression.
ΔU° = q + w
ΔU° = -27.0 J + 83.0 J
ΔU° = 56.0 J
How many moles of NaCl , if mixed with excess Pb2+ ions in solution, would be needed to form 45.5 g of PbCl2 ?
The number of mole of NaCl needed to react with excess Pb²⁺ to produce 45.5 g of PbCl₂ is 0.328 mole
We'll begin by calculating the number of mole in 45.5 g of PbCl₂. This can be obtained as follow:
Mass of PbCl₂ = 45.5 g
Molar mass of PbCl₂ = 207 + (35.5×2) = 278 g/mol
Mole of PbCl₂ =?Mole = mass / molar mass
Mole of PbCl₂ = 45.5 / 278
Mole of PbCl₂ = 0.164 mole Finally, we shall determine the number of mole of NaCl needed to produce 0.164 mole (i.e 45.5 g) of PbCl₂. This can be obtained as follow:2NaCl + Pb²⁺ —> PbCl₂ + 2Na⁺
From the balanced equation above,
2 moles of NaCl reacted to produce 1 mole of PbCl₂
Therefore,
Xmol of NaCl will react to produce 0.164 mole of PbCl₂ i.e
Xmol of NaCl = 2 × 0.164
Xmol of NaCl = 0.328 mole
Thus, the number of mole of NaCl needed for the reaction is 0.328 mole
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Demonstrate how you can prepare 250ml 0.25M hydrogen peroxide from a solution of 20g/100ml of hydrogen peroxide.
To prepare 250 ml 0.25 M hydrogen peroxide, 10.63 ml of 20g/100 ml hydrogen peroxide has been taken and made up the volume to 250 ml.
The dilution of the sample can be prepared with the help of expression:
M1V1 = M2V2
M1 = molarity of the concentrated solution
V1 = volume of concentrated solution
M2 = molarity of diluted solution
V2 = volume of diluted solution.
The molarity of concentrated solution has been:
Molarity = [tex]\rm \dfrac{weight}{molecular\;weight}\;\times\;\dfrac{1000}{Volume\;(ml)}[/tex]
The 20g/100 ml Hydrogen peroxide has molarity:
Molarity = [tex]\rm \dfrac{20}{34.0147}\;\times\;\dfrac{1000}{100}[/tex]
Molarity of Hydrogen peroxide = 5.879 M
The volume of 5.879 M hydrogen peroxide is required to prepare 0.25 M hydrogen peroxide has been:
Volume of Hydrogen peroxide (20g/100 ml) [tex]\times[/tex] 5.879 = 250 ml [tex]\times[/tex] 0.25 M
Volume of Hydrogen peroxide (20g/100 ml) = 10.63 ml.
To prepare 250 ml 0.25 M hydrogen peroxide, 10.63 ml of 20g/100 ml hydrogen peroxide has been taken and made up the volume to 250 ml.
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What is the molarity of calcium bicarbonate if 9.52 mL of 1.20 M HNO3 is required in a titration to neutralize 50.0 mL of a solution of Ca(HCO3)2?
The molarity of calcium bicarbonate if 9.52 mL of 1.20 M HNO3 is required in a titration to neutralize 50.0 mL of a solution of Ca(HCO3)2 is 0.228M.
HOW TO CALCULATE MOLARITY:
The molarity of a substance in a titration experiment can be calculated by using the following formula:C1V1 = C2V2
Where;
C1 = concentration of acid (M)V1 = initial volume of acid (mL)C2 = concentration of base (M)V2 = volume of the base (mL)According to this question;
V1 = 9.52mlV2 = 50.0mlC1 = 1.20MC2 = ?1.20 × 9.52 = C2 × 50
11.424 = 50C2
C2 = 11.424 ÷ 50
C2 = 0.228M
Therefore, the molarity of calcium bicarbonate if 9.52 mL of 1.20 M HNO3 is required in a titration to neutralize 50.0 mL of a solution of Ca(HCO3)2 is 0.228M.Learn more at: https://brainly.com/question/3003621?referrer=searchResults
How many π electrons are there in adenine? State which atoms contribute one electron to the π MOs and which atoms contribute two electrons?
Answer:
12 π electrons.
Explanation:
The structure of adenine can be seen below.
From the diagram, the total number of electrons in adenine is 70 electrons where 20 of them are core electrons.
Also from this same structure, we will notice that we have a total number of 12 π electrons.
i.e.
Each one of these five atoms described takes part in the π electron. These are N-1, N-3, N-7 which comprise of 2σ bonds, and also each of three N contributes one π electron.
Similarly, N-9 and N-10 contain 3σ bonds; Hence, each of them donates two electrons.
Thus;
5C = 5π electrons
3N = 3π electrons
2N = 4π electrons
= 12π electrons
Calculate the amount of heat required to raise the temperature of a 32g sample of water from 8°C to 22°C.
Answer:
The amount of heat required to raise the temperature of a 32g sample of water from 8°C to 22°C is 1,874.432 J
Explanation:
Calorimetry is the measurement and calculation of the amounts of heat exchanged by a body or a system.
Sensible heat is the amount of heat that a body absorbs or releases without any changes in its physical state (phase change).
Between heat and temperature there is a direct proportional relationship. The constant of proportionality depends on the substance that constitutes the body and its mass, and is the product of the specific heat and the mass of the body. So, the equation that allows to calculate heat exchanges is:
Q = c * m * ΔT
where Q is the heat exchanged by a body of mass m, constituted by a substance of specific heat c and where ΔT is the variation in temperature.
In this case:
c= 4.184 [tex]\frac{J}{g*C}[/tex]m= 32 gΔT= Tfinal - Tinitial= 22°C - 8°C= 14°CReplacing:
Q= 32 g* 4.184 [tex]\frac{J}{g*C}[/tex] *14 °C
Solving:
Q= 1,874.432 J
The amount of heat required to raise the temperature of a 32g sample of water from 8°C to 22°C is 1,874.432 J
How do generators use magnets to create electricity
Answer:The properties of magnets are used to make electricity.
Explanation: Moving a magnet around a coil of wire, or moving a coil of wire around a magnet, pushes the electrons in the wire and creates an electrical current. Electricity generators essentially convert kinetic energy (the energy of motion) into electrical energy.
Plz what’s the answer to this
Answer: E
Explanation:hope this helps you out
Is there anyone studying a doctor in pharmacy?
Answer:
no I am in 8 standard
I am already preparing for a doctor for my future
Describe the transfer of thermal energy as the ice cream melts and as it becomes solid again. In both situations, describe which objects are gaining and losing energy.
Answer:
Melting = endothermic, solid = exothermic
Explanation:
Ok so when ice cream melts, that requires heat, so it’s Endothermic. In order to melt it, it requires heat, heat is entering. When it becomes solid again, that is exothermic because it is losing heat in order to become cool again.
Answer this question correctly and you'll get a free brainliest. and a Thank you, etc.
Answer: When the metamorphic rock continues to heat up it will eventually melt creating molten rock. When it cools it will become igneous rock
Explanation:
:D
Answer:
As metamorphic rock continues to heat up, it can eventually melt and become molten/magma. When the molten rock cools it forms an igneous rock.
Explanation:
basically it need heat as hot as lava.
Suppose you have 300.0 mL of a 0.450 M sodium hydroxide solution.
How many moles of sodium hydroxide are in the solution?
Answer:
135 moles
Explanation:
300*0.45
= 135
PLS GIVE BRAINLIEST
3/2 moles
Explanation:We are given:
Molarity of the solution = 0.450 M
Volume of the Solution = 300 mL OR 0.3 L
Solving for the number of moles:
We know that the formula for molarity:
M = nV (where n is the number of moles and V is the volume in Liters)
replacing the variables
0.450 = n * (0.3)
n = 0.450 / 0.3
n = 3/2 moles
Therefore, we have 3/2 moles of Na(OH) in the give solution
4. One mole of oxygen contains 6.02 x 102 molecules. How many oxygen molecules are in
5.55 moles of oxygen gas?|
Answer:
3.34x10²⁴ molecules of oxygen
Explanation:
1 Mole of particles of any kind of gases or particles are always 6.022x10²³.
1 mole of electrons are 6.022x10²³ electrons
1 mole of any gas are 6.022x10²³ molecules
1 mole of oxygen are 6.022x10²³ molecules. Thus, 5.55 moles are:
3.34x10²⁴ molecules of oxygen