Answer:
There are light absorbing color bodies called chromophores that are present in dyes. Ultraviolet rays are one of the causes of fading because they can break down chemical bonds and fade the color in objects.
How many moles of ethylene glycol must be added to 1 kg of water to make a solution with a freezing point of -2.4°C? The freezing point depression constant for water is 1.86°C•kg/mol. What is the molality of the solution?
Answer: 1.29 moles of ethylene glycol must be added to 1 kg of water to make a solution with a freezing point of -2.4°C. Molality of solution is 1.29 m.
Explanation:
Depression in freezing point is given by:
[tex]\Delta T_f=i\times K_f\times m[/tex]
[tex]\Delta T_f=T_f^0-T_f=(0-(-2.4))^0C=2.4^0C[/tex] = Depression in freezing point
i= vant hoff factor (for non electrolyte , i = 1)
[tex]K_f[/tex] = freezing point constant for water= [tex]1.86^0C/kgmol[/tex]
m= molality =[tex]\frac{\text{moles of solute}}{\text{weight of solvent in kg}}[/tex]
m= molality =[tex]\frac{x}{1kg}[/tex]
[tex]2.4^0C=1\times 1.86^0C/kgmol\times \frac{x}{1kg}[/tex]
[tex]x=1.29[/tex]
Molality = [tex]\frac{\text{moles of solute}}{\text {weight of solvent in kg}}=\frac{1.29mol}{1kg}=1.29m[/tex]
Thus 1.29 moles of ethylene glycol must be added to 1 kg of water to make a solution with a freezing point of -2.4°C. Molality of solution is 1.29 m.
Answer:
1) C (m=T f/Kf)
2) 2.4 C
3) 1.3 m
4) 1.3 moles
Explanation:
This is correct on ed
what is the difference between basis and basic
Answer:
Basis and basic are two different words.
In English, Basis is used as a noun while basic is used as an adjective. Basis term refers as the base or starting point of any discussion.
For example: Bread is a basic ingredient of cake.
On the basis of Mendel's hypothesis.
In chemistry, Basis set is used as a set of functions that represent the electronic wave function in the density-functional theory which forms an algebraic equations that can be easily implemented on a computer.
While Basic term is used for substances that can accept a hydrogen ion (H+) from another substance and have pH above 7. such as sodium.
So, It is not important that both the terms, basis and basic change their English meaning if used in chemistry, they both can be used with English meaning in chemistry as well. Bases and basic, both the terms can be used as either English or Chemistry without affecting the meaning.
A student places a 12-gram cube of Ice Inside a container. After six hours, the student returns to observe the contents of the container. Which
sentence suggests that the container is an open system?
ОА
The container contains 12 grams of liquid water and no ice.
B.
The container contains 12 grams of Ice and no liquid water.
D.
The container contains 8 grams of liquid water and no ice.
The container contains 8 grams of ice and 4 grams of liquid water.
The container contains 8 grams of liquid water and 4 grams of water vapor.
E
Answer:
I think its D sorry if im wrong
Answer:i think its D
Explanation:
50 POINTS! Fill in the chart below to identify and describe the functional groups associated with organic chemistry.
Name General Structure Properties/Uses
Alcohol
Aldehyde
Ketone
Fatty acid
Ether
Answer:
Alcohol
Structure: Alcohols are organic molecules assembled from carbon (C), oxygen (O), and hydrogen (H) atoms.
Property: The Boiling Point of Alcohols. Alcohols generally have higher boiling points in comparison to other hydrocarbons having equal molecular masses.
Aldehyde
Structure: DescriptionAn aldehyde is a compound containing a functional group with the structure −CHO, consisting of a carbonyl centre.
Property: The polarity of the carbonyl group notably affects the physical properties of melting point and boiling point, solubility, and dipole moment.
Ketone
Structure: A ketone is a functional group with the structure RC(=O)R', where R and R' can be a variety of carbon-containing substituents.
Property: Ketones are soluble in water but their solubility decreases with increase in the length of the chain.
Fatty Acid
Structure: a fatty acid consists of a straight chain of an even number of carbon atoms, with hydrogen atoms along the length of the chain and at one end of the chain and a carboxyl group (―COOH) at the other end.
Property: Fatty acids are solid at room temperature, while unsaturated fatty acids are liquid.
Ether
Structure: a class of organic compounds characterized by an oxygen atom bonded to two alkyl or aryl groups.
Property: An ether molecule has a net dipole moment due to the polarity of C-O bonds.
The functional group associated with ethanol is -OH, the aldehyde is -COH, the ketone is -CO, the fatty acid is -COOH, and ether is ROR.
The functional groups have been the atoms that have different constituents and properties with respect to other groups.
The functional group associated with the following groups has been:
Alcohol: It has been liquid at room temperature with the functional group -OH.Aldehyde: It has been soluble in water with the functional group -COH.Ketone: It has been soluble in water, with C=O in the structure as a functional group.Fatty acid: It has been a long chain acid, with the presence of carboxylic group -COOH.Ether: It has been the pleasant smelling compounds with the presence of the R-O-R group as the functional group.
The functional group associated with ethanol is -OH, the aldehyde is -COH, the ketone is -CO, the fatty acid is -COOH, and ether is ROR.
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Why are prefixes often added to SI units?
Answer: SI prefixes are used to form decimal multiples and submultiples of SI units. They should be used to avoid very large or very small numeric values.
Explanation: ^^^
ANSWER IT CORRECTLY PLEASE!!
The Osmotic pressure of blood is 7.65 ATM at 310 k. An aqueous solution of glucose is isotonic with blood has the percentage by volume
a.5.41%
b.3.54%
c.4.53%
d.53.4%
Answer:
Explanation:
Pv = n RT
P =7.65, T= 310K, for glucose n = moles= weight/molar mass= weight/180, R is gas constant
7.65* V =W/180 *0.0821 * 310
w/v= 7.65*180/0.0821*310 = 1377/25.45 = 54.10 =5.4%
I NEED HELP PLEASE, THANKS SO MUCH! :)
Solids, liquids and gases are the three most commonly accepted phases of matter. Explain the properties of each phase, including their relative energy.
Gases, liquids and solids are all made up of atoms, molecules, and/or ions, but the way the particles inside them differ.
In a gas, the molecules are spread wide apart and moves freely at high speeds
In a liquid, the more closer to each other and will vibrate or slip past each other
In a solid, the molecules are tightly packed, making no room for each other and harder to move. These molecules vibrate and jiggle but, don't move
This is how fluorine appears in the periodic table. A green box has F at the center and 9 above. Below it says fluorine and below that 19.00. A blue arrow points to 9. What information does "9” give about an atom of fluorine? Select three options. the atomic number the atomic mass the number of protons the number of electrons the number of neutrons
I NEED HELP PLEASE, THANKS! :)
The density of water at 4.00°C is 0.967 g/mL. How many molecules of water are present in a 499.8 mL bottle of water? Express your answer to the correct number of significant figures.
Answer:
[tex]\large \boxed{1.615 \times 10^{25}\text{ molecules water}}[/tex]
Explanation:
You must calculate the mass of the water, convert it to moles, and then calculate the number of molecules.
1. Mass of water
[tex]\text{Mass } = \text{499.8 mL} \times \dfrac{\text{0.967 g}}{\text{1 mL}} = \text{483.3 g}[/tex]
2. Moles of water
[tex]\text{Moles of water} = \text{483.3 g water} \times \dfrac{\text{1 mol water}}{\text{18.02 g water}} = \text{26.82 mol water}[/tex]
3. Molecules of water
[tex]\text{No. of molecules} = \text{26.82 mol water} \times \dfrac{6.022 \times 10^{23}\text{ molecules water}}{\text{1 mol water}}\\\\= \mathbf{1.615 \times 10^{25}}\textbf{ molecules water}\\\text{The sample contains $\large \boxed{\mathbf{1.615 \times 10^{25}}\textbf{ molecules water}}$}[/tex]
The number of molecules of water present in the bottle is 1.62×10²⁵ molecules.
We'll begin by calculating the mass of the water in the bottle.
Density of water = 0.967 g/mLVolume of water = 499.8 mLMass of water =?Mass = Density × Volume
Mass of water = 0.967 × 499.8
Mass of water = 483.3066 g
Finally, we shall determine number of molecules of water in the bottle.
From Avogadro's hypothesis,
1 mole of water = 6.02×10²³ molecules
But,
1 mole of water = 18 g
Thus, we can say that:
18 g of water = 6.02×10²³ molecules
Therefore,
483.3066 g of water = (483.3066 × 6.02×10²³) / 18
483.3066 g of water = 1.62×10²⁵ molecules
Thus, the number of molecules of water in the bottle is 1.62×10²⁵ molecules.
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Am I correct? Because I’m kinda in between answers
Answer:
yh you are correct. the pattern is correct! :)
Answer:
Yep! :)
Explanation:
A.
B.
C.
D.
what’s could be the correct answer?
Elements that form ionic bonds generally have how many valence electrons?
Answer:
they should have a number that can completely transfer and fill the other atom
Explanation:
example:
sodium(2.8.1)and Chlorine(2.8.7)the sodium will give chlorine the 1 valence electrobo so they both become stable(2.8)±and(2.8.8)–
magnesium(2.8.2)and oxygen(2.6)same way as above to abtain mg(2.8)±²and oxygen(2.8)–²
Diagrams, tables, and graphs are used by scientists to
Answer:
Since most of the data scientist collect is quantitative, data tables and charts are usually used to organize the information • Graphs are created from data tables • hope that helps love!
A solution has a pH of 8.4. what is the H+ concentration of the solution?
A solution has a pH of 11. What is the H+ concentration of the solution? Is the solution an acid or base?
Your father goes to the store to buy cleaner to remove such deposits from your bathtub. He has a choice between a product containing lemon juice (H+ =10^-2.5M) and one containing vinegar (H+ = 10^ -3.3M) which product would you recommend he purchase and why?
[H+]=3.98x10^-9
[H+]=10^-pH=10^-8.4
[H+]=10^-11, base
[H+]=10^-pH=10^-11
A solution with a pH of more than 7 is basic.
Lemon juice because it is more acidic
pH of lemon juice: 2.5
pH of vinegar: 3.3
Since the pH of lemon juice is lower, it is more acidic and will be more effective at removing the basic deposits.
How many liters of hydrogen gas is produced from 3.712 g of magnesium with 104.2ml of 1.385 mol/L HCL (aq) at SATP? Please show your work and explain it. I really need help with this question, it's on one of my quizzes.
Answer:
[tex]V=1.61L[/tex]
Explanation:
Hello,
In this case, the undergoing chemical reaction is:
[tex]Mg+2HCl\rightarrow MgCl_2+H_2[/tex]
Next, we compute the reacting moles of each reactants:
[tex]n_{Mg}=3.712gMg*\frac{1molMg}{24.305 gMg}=0.153molMg[/tex]
[tex]n_{HCl}=1.385\frac{molHCl}{L}*0.1042L=0.144molHCl[/tex]
Then, as magnesium and hydrohloric acid are in a 1:2 molar ratio 0.153 moles of magnesium will completely react with 0.306 moles of hydrochloric acid yet we only have 0.144 moles, therefore, limiting reactant is hydrochloric acid. Thus, we compute the produced moles of hydrogen:
[tex]n_{H_2}=0.144molHCl*\frac{1molH_2}{2molHCl} =0.072molH_2[/tex]
Finally, we use the ideal gas equation with T=298K and 1atm (STP conditions) to compute the liters of hydrogen gas:
[tex]PV=nRT\\\\V=\frac{nRT}{P}=\frac{0.072mol*0.082\frac{atm*L}{mol*K}*273K}{1atm}\\ \\V=1.61L[/tex]
Best regards.
what is the best way to make a supersaturated solution?
A. cool the solution
B. Stir the solution
C. Heat the solution
D. Evaporate the solution
C.heat the solution
In which kingdom do all organisms have cells that lack a cell wall?
fungsi
plants
animals
bacteria
Answer:
The answer is animals
Explanation:
Plants and fungi have a cell wall, and although most bacteria lack a cell wall, the question is asking in which kingdom do ALL organisms lack a cell wall. Hope this helps.
Answer:Bacteria
Explanation:
Compare the wavelength and energy of ultraviolet rays to visible light
Answer:
Visible wavelengths range from 0.0007 milimeters for red light, through orange, yellow, green, and blue, to 0.0004 milimeters for violet light.
Ultraviolet is shorter wavelengths than violet.
Hope This Helps.
boron has two naturally occurring isotopes .there are 10 b(20%)and 11b(80%).what is the average atomic mass of boron
Answer:
Explanation:
Average Atomic mass of any element =[ ∑ Abundance* mass of element] /100
= 10*20 +11*80 /100
= .........
Hope this helps you
what is the answer to y=1/2-x+1
Answer:
X= -Y + 2/2 Y=-X + 3/2
Explanation:
I don't know how to simplify it anymore. You would get x=-y+3/2 and y=-x+3/2
Answer:
Explanation:
(-1/2,1)
Connie was making sodium chloride by adding an acid to an alkali. She followed the progress of the reaction with a pH sensor .What else could she have used to detect when the reaction was complete?
What Connie could have used to detect when the chemical reaction was complete is an: acid-base indicator.
A chemical reaction is a chemical process that involves the continuous rearrangement (transformation) of either the ionic, atomic or molecular structure of a chemical element through the breakdown and formation of chemical bonds, in order to produce a chemical compound.
When a strong acid such as Hydrogen chloride (HCl) react with a strong alkali such as Sodium hydroxide (NaOH), it gives rise to the formation of Sodium chloride (NaCl) and Water ([tex]H_2O[/tex]);
[tex]HCl + NaOH[/tex] ----> [tex]NaCl + H_2O[/tex]
The progress of the above chemical reaction can be followed by using a pH sensor and the final pH of a strong acid and strong base is seven (7), meaning it is neutral.
However, Connie could make use of an acid-base indicator to detect when the chemical reaction is complete.
An acid-base indicator can be defined as a chemical substance that changes color with respect to the pH (hydrogen ion concentration) of a solution or chemical reaction. Some examples of an acid-base indicator are:
Litmus paper.Methyl red.Red cabbage juice.Bromothymol blue.Methyl orange.Phenolphthalein.In conclusion, an acid-base indicator is typically used for detecting when a chemical reaction between an acid and an alkali is complete.
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Answer:When a strong acid such as Hydrogen chloride (HCl) react with a strong alkali such as Sodium hydroxide (NaOH), it gives rise to the formation of Sodium chloride (NaCl) and Water ();
---->
Explanation:
Determine the boiling point of a 3.70 m solution of phenol in benzene. Benzene has a boiling point of 80.1°C and a boiling point elevation constant of 2.53°C•kg/mol.
Answer: The boiling point of a 3.70 m solution of phenol in benzene is [tex]89.5^0C[/tex]
Explanation:
Elevation in boiling point:
[tex]\Delta T_b=i\times k_b\times m[/tex]
where,
[tex]\Delta T_b[/tex] = change in boiling point
i= vant hoff factor = 1 (for benzene which is a non electrolyte )
[tex]k_b[/tex] = boiling point constant = [tex]2.53^0C/kgmol[/tex]
m = molality = 3.70
[tex]T_{solution}-T_{solvent}=i\times k_b\times m[/tex]
[tex]T_{solution}-80.1^0C=1\times 2.53\times 3.70[/tex]
[tex]T_{solution}=89.5^0C[/tex]
Thus the boiling point of a 3.70 m solution of phenol in benzene is [tex]89.5^0C[/tex]
Answer:
First Question:
C. ΔTb = Kbm
Second Question:
C. 9.36° C
Third Question:
89.5
Explanation:
Got it right.
Acetylene is the simplest hydrocarbon
that contains carbon-carbon triple bond.
Hydrocarbons are the compounds of
carbon and hydrogen.
identify the branch of Chemistry??
Answer:
organic chemistry
because it is study of carbon containing substances
Organic chemistry is the branch of Chemistry where hydrocarbons are the compounds of carbon and hydrogen.
What is organic chemistry?Organic chemistry is the study of the structure, properties, composition, reactions, and preparation of carbon-containing compounds.
Hydrocarbons Derivatives are compounds which are made up of hydrogen and carbon with specific functional groups attached to them.
Examples:- Aldehydes, ketones, carboxylic acids, alcohols, alkyl halides, ethers, amines etc.
Hence, organic chemistry is the branch of Chemistry where
hydrocarbons are the compounds of carbon and hydrogen.
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Which of the following is true about the principle of the conservation of mass? *
1 point
d. The mass of the products is never equal to the mass of the reactants.
e. The mass of the products is less than the mass of the reactants.
f. The mass of the products is equal to the mass of the reactants.
g. The mass of the products is greater than the mass of the reactants.
Answer:
F
Explanation:
"The mass of the products is equal to the mass of the reactants" is true about the principle of the conservation of mass.
So, option f is correct one.
What is the principle of conservation of mass?The principle of the conservation of mass states that mass can neither be created nor be destroyed in a chemical reaction, it only transferred from reactants to products. It means that mass of reactants is equal to mass of products.Example when wood burns the mass of shoot, ashes, and gases equal to the original mass of of charcoal and oxygen when it first react.To learn more about conservation of mass here.
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What is the temperture at which all molecular movements stop called
Answer:
Absolute Zero
Explanation:
at 0 Kelvin, nothing can move and entropy reaches 0
Answer:
absolute zero
Explanation:
Consider the incomplete reaction below.
NaOH + X Right arrow. NaCH3COO + H2O
What is X in this reaction?
NH4OH
H3PO4
H2CO3
CH3COOH
A chemical reaction involves the interaction of reactants. The substance X ,must be an acid and in this case is CH3COOH
What is a reaction?In chemistry, a reaction is said to occur when substances interact in such a way that other new substances are formed.
Now let us look at the particular reaction; NaOH + X ----> NaCH3COO + H2O. The substance X must be an acid. Hence, the most likely susbstance is CH3COOH.
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20 points!! Please help me! Will mark Brainliest!! complete the following word equations:) also write the balanced equation, full ionic equation, and net ionic equation. Also include the states:)
a) zinc nitrate + calcium sulphide—>
b) potassium + calcium chloride—>
50cm3 of sodium hydroxide solution was titrated against a solution of sulfuric acid. The concentration of the sodium hydroxide solution was 20g/dm3. Work out the concentration of the acid in grams per litre if it took 25cm3 of acid to completely neutralise the alkali. The relative molecular mass of sulfuric acid is 98.
Answer:
49 g/L is the concentration of the acid
Explanation:
Firstly, we proceed to write the equation of reaction.
2NaOH + H2SO4 ——-> Na2SO4 + 2H2O
We can see that 1 mole of the base reacted with two moles of the acid.
kindly note that dm^3 is same as liter
Firstly, we need to get the concentration of the reacted sulphuric acid in g/L
we use the simple titration equation below;
CaVa/CbVb = Na/Nb
From the question;
Ca = ?
Va = 25 cm^3
Cb = 20 g/L
we convert this to concentration in mol/L
Mathematically, that is concentration in g/L divided by molar mass in g/mole
molar mass of NaOH = 40 g/mol
so we have; 20g/L / 40 = 0.5 mol/L
Vb = 50 cm^3
Na = 1
Nb = 2
Where C represents concentrations, V volumes and N , number of moles
Now, substitute the values;
Ca * 25/0.5 * 50 = 1/2
25Ca/25 = 0.5
So Ca = 0.5 mol/L
Now to get the concentration of H2SO4 in g/L
What we do is to multiply the concentration in mol/L by molar mass in g/mol
That would be 0.5 * 98 = 49 g/L
The concentration of the acid in grams per litre is 49g/L
From the question,
We are to determine concentration of the sodium hydroxide solution.
First, we will write a balanced chemical equation for the reaction.
The balanced chemical equation for the reaction is
2NaOH + H₂SO₄ → Na₂SO₄ + 2H₂O
This means,
2 moles of NaOH is required to completely neutralize 1 mole of H₂SO₄
From the formula
[tex]\frac{C_{A}V_{A} }{C_{B}V_{B} }=\frac{n_{A} }{n_{B} }[/tex]
Where
[tex]C_{A}[/tex] is the concentration of acid
[tex]C_{B}[/tex] is the concentration of base
[tex]V_{A}[/tex] is the volume of acid
[tex]V_{B}[/tex] is the volume of base
[tex]n_{A}[/tex] is the mole ratio of acid
[tex]n_{B}[/tex] is the mole ratio of base
From the question
[tex]V_{A}= 25 \ cm^{3}[/tex]
[tex]C_{B} = 20 \ g/dm^{3}[/tex]
Convert this to mol/dm³
Molar mass of NaOH = 40 g/mol
Using the formula
[tex]Concentration\ in \ mol/dm^{3} =\frac{Concentration\ in \ g/dm^{3}}{Molar\ mass}[/tex]
∴ Concentration of the NaOH in mol/dm³ = [tex]\frac{20}{40}[/tex]
Concentration of the NaOH in mol/dm³ = 0.5 mol/dm³
∴ [tex]C_{B} = 0.5 \ mol/dm^{3}[/tex]
and
[tex]V_{B} = 50 \ cm^{3}[/tex]
From the balanced chemical equation
[tex]n_{A} = 1[/tex]
[tex]n_{B} = 2[/tex]
Putting the parameters into the formula, we get
[tex]\frac{C_{A} \times 25}{0.5 \times 50}= \frac{1}{2}[/tex]
Now, this becomes
[tex]2 \times 25 \times C_{A}=0.5 \times 50 \times 1[/tex]
Then, we get
[tex]50 C_{A} = 25[/tex]
∴ [tex]C_{A} = \frac{25}{50}[/tex]
[tex]C_{A} = 0.5 \ mol/dm^{3} = 0.5 \ mol/L[/tex]
Now, we will determine the concentration in g/L
From the formula,
Concentration in g/L = Concentration in mol/L × Molar mass
From the question,
Molar mass of sulfuric acid = 98
∴ Concentration of the acid in g/L = 0.5 × 98
Concentration of the acid in g/L = 49 g/L
Hence, the concentration of the acid in grams per litre is 49g/L
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This beaker contains an aqueous solution of copper II nitrate.
Write the chemical formula for the solute chemical that is dissolved):
Write the chemical formula for the solvent( liquid that does the dissolving)
Answer:
See the answer below
Explanation:
Aqueous solution of copper II nitrate contains solute of copper II nitrate dissolved in water. The equation for the reaction is as below:
[tex]Cu(NO_3)_2 (s)[/tex] + [tex]H_2O (l)[/tex] --> [tex]Cu(NO_3)_2 (aq)[/tex]
Hence, the solute chemical is copper II nitrate while the solvent is water.
Chemical formula of copper II nitrate - [tex]Cu(NO_3)_2[/tex]
Chemical formula of water - [tex]H_2O[/tex]
A balloon has a volume of 10,500 liters, and the temperature is 15°C. If the temperature were -25°C, what would the volume of the balloon be?
12,194 L
9,042 L
12,194 L is the answer!
Explanation:
Water has the maximum density at the temperature of 4°Celsius. So, it expands at temperatures higher or lower than 4°C, knowing that at the temperature of -25°C the water can't have a lower volume than the one at 15°C.
Answer:
12, 194 L
That's your answer!!!