A solution is made by dissolving
37.5g of sodium sulfide (Na2S) in
217g of water.
What is the molality of the solution?
Answer:
THE MOLARITY IS 2.22 MOL/DM3
Explanation:
The solution formed was as a result of dissolving 37.5 g of Na2S in 217 g of water
Relative molecular mass of Na2S = ( 23* 2 + 32) = 78 g/mol
Molarity in g/dm3 is the amount of the substance dissolved in 1000 g or 1 L of the solvent. So we have;
37.5 g of Na2S = 217 g of water
( 37.5 * 1000 / 217 ) g = 1000 g of water
So, 172.81 g/dm3 of the solution
So therefore, molarity in mol/dm3 = mol in g/dm3 / molar mass
Molarity = 172.81 g/dm3 / 78 g/mol
Molarity = 2.22 mol/dm3
The molarity of the solution is 2.22 mol/dm3
Answer:
The answer is 2.22mol
Explanation:
Select the statements that correctly describe buffers.
A) A buffer is made up of a strong acid and a strong base.
B) The pH of a buffer solution does not change significantly when a small amount of acid is added.
C) The pH of a buffer solution is determined by the ratio of the concentration of acid to the concentration of base.
D) The K_a of a buffer decreases slightly when a small amount of acid is added to the buffer solution.
E) A strong acid added to the buffer solution reacts with the weak acid of the buffer.
Answer:
B) The pH of a buffer solution does not change significantly when a small amount of acid is added.
C) The pH of a buffer solution is determined by the ratio of the concentration of acid to the concentration of base.
Explanation:
Buffer solution is useful in maintaining the pH of a solution constant . It is made of a weak acid and its salt or a weak base and its salt . Ph of a buffer is given by the following relation .
pH = pKa + log [ A⁻ ] / [ HA ]
A- is a base and HA is a weak acid .
When we add acid , it reacts with A⁻ or base and gets neutralised .
When we add base , it reacts with acid HA and gets neutralised . In this way it maintains the pH of the solution .
Correct statements are as follows:
B) When a tiny amount of solvent is introduced to a buffer, the pH doesn't really alter considerably.
C) The ratio of acids to base concentration determines the pH of a phosphate buffer.
So, options B) and C) are correct.
Define pH.ph scale used in science to measure the acidity or alkalinity of an aqueous solution. pH originally stood for "potential of hydrogen." The pH of acidic solutions is lower than that of basic or alkaline solutions.
Correct statements are as follows:
B) When a tiny amount of solvent is introduced to a buffer, the pH doesn't really alter considerably.
C) The ratio of acids to base concentration determines the pH of a phosphate buffer.
So, options B) and C) are correct.
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QUESTION 10
The stoppers were weighed directly on the balance, but liquids and powders cannot be. Explain why the use
the tare button would be especially useful for liquids and powdered substances.
What circumstances during the French Revolution permitted the metric system to gain a foothold?
Answer:
The trade was difficult with the old system.
Explanation:
The existing system for the measurement of goods did not work well in the trade because there are different system used by the people of different cities so metric system was used in the whole country in place of the old system of measurement during the French Revolution in order to make the trade easier and quick across the country. This metric system is extensively used in the trade as compared to the old system of measurement due to its easiness and fast.
Given the ion C2O4-2, what species would you expect to form with each of the following ions?
A. K+______
B. Cu2+______
C. Bi3+______
D. Pb4+______
E. NH4+______
F. H+______
Answer:
A. K₂C₂O₄ Potassium oxalate
B. CuC₂O₄ Copper oxalate
C. Bi₂(C₂O₄)₃ Bismuth (III) oxalate
D. Pb(C₂O₄)₂ Lead (IV) oxalate
E. (NH₄)₂C₂O₄ Ammonium oxalate
F. HC₂O₄⁻ Acid oxalate
Explanation:
C₂O₄⁻² → oxalate anion
This is the conjugate base from the H₂C₂O₄ which is the oxalic acid. A weak dyprotic acid that can release 2 protons.
A. 2K⁺ + C₂O₄⁻² → K₂C₂O₄ Potassium oxalate
It can be formed by the neutralization of the acid with the base
H₂C₂O₄ + 2KOH → K₂C₂O₄ + 2H₂O
B. Cu²⁺ + C₂O₄⁻² ⇄ CuC₂O₄ ↓
This is a precipitate.
C. 2Bi³⁺ + 3C₂O₄⁻² ⇄ Bi₂(C₂O₄)₃ ↓
This is a precipitate.
D. Pb⁴⁺ + 2C₂O₄⁻² ⇄ Pb(C₂O₄)₂ ↓
This is a precipitate.
E. 2NH₄⁺ + C₂O₄⁻² ⇄ (NH₄)₂C₂O₄ ↓
This is a precipitate.
F. This is the conjugate strong base, for the weak acid
H⁺ + C₂O₄⁻² ⇄ HC₂O₄⁻
HC₂O₄⁻ + H₂O ⇄ C₂O₄⁻² + H₃O⁺ Ka
HC₂O₄⁻ + H₂O ⇄ H₂C₂O₄ + OH⁻ Kb
HC₂O₄⁻ is an amphoteric compound
A. K₂C₂O₄ →Potassium oxalate
B. CuC₂O₄ →Copper oxalate
C. Bi₂(C₂O₄)₃ →Bismuth (III) oxalate
D. Pb(C₂O₄)₂ →Lead (IV) oxalate
E. (NH₄)₂C₂O₄ →Ammonium oxalate
F. HC₂O₄⁻ →Acid oxalate
Given:
C₂O₄⁻² → oxalate anionIt is the conjugate base from the H₂C₂O₄ which is the oxalic acid. A weak diprotic acid that can release 2 protons.
The reactions involved in this are:
A. 2K⁺ + C₂O₄⁻² → K₂C₂O₄
B. Cu²⁺ + C₂O₄⁻² ⇄ CuC₂O₄ ↓
C. 2Bi³⁺ + 3C₂O₄⁻² ⇄ Bi₂(C₂O₄)₃ ↓
D. Pb⁴⁺ + 2C₂O₄⁻² ⇄ Pb(C₂O₄)₂ ↓
E. 2NH₄⁺ + C₂O₄⁻² ⇄ (NH₄)₂C₂O₄ ↓
↓- This symbol denotes the precipitate formation.
F. H⁺ + C₂O₄⁻² ⇄ HC₂O₄⁻
This is the conjugate strong base, for the weak acid.HC₂O₄⁻ is an amphoteric compound.
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Does the density of a liquid depend on its volume? Write your answer as a CER.
Answer: Yes
Explanation:
Density of a liquid depend on its volume. This is because Density is mass of liquid divided by volume.
Density is inversely proportional to volume.
As density increases, volume decreases and vice versa. The density for water is 1g/ milliliter but it changes with changes in temperature or there are impurities dissolved in it. Ice is less dense that liquid water and it's the major reason it's float because it's volume is inversely proportional to it's density.
Rank the measurements from largest to smallest. .75 Times 10^-3 mL, 325 mu L, 4.11 Times 10^-4 dL.
Given :
Some volume measurements :
[tex]0.75 \times 10^{-3}\ mL,\ 325\ \mu L,\ 4.11 \times 10^{-4}\ dL[/tex]
To Find :
Rank the measurements from largest to smallest.
Solution :
Now , [tex]1\ \mu l=10^{-3}\ ml[/tex].
Also , [tex]1\ dl=100\ ml[/tex].
So , the measurements in same units are :
[tex]0.75 \times 10^{-3}\ mL,\ 325 \times 10^{-3}\ mL , 4.11 \times 10^{-4} \times 100\ mL\\\\0.75\times 10^{-3}\ mL ,\ 325\times 10^{-3}\ mL ,\ 41.1\times 10^{-3}\ mL[/tex]
So , the order from highest to lowest is :
[tex]325\times 10^{-3}\ mL ,\ 41.1\times 10^{-3}\ mL ,\ 0.75\times 10^{-3}\ mL[/tex]
Hence , this is the required solution .
325 µL > 41.1 µL > 0.75 µL is the ranking of the measurements from largest to smallest.
Measurements have a crucial role in many aspects of daily life, including science, engineering, construction, and cookery. They enable precise measurement, comparison, and communication of an object's size, quantity, or amount. The most widely used measurement systems globally are the metric and imperial systems. There are other measurement systems as well. The International System of Units (SI), generally known as the metric system and based on multiples of ten, is extensively used. It comprises measures for length and mass including metres, grammes, and litres. Units like feet, pounds, and gallons are part of the imperial system, which is primarily used in the United States.
1 mL = 1000 µL
1 dL = 100 mL
.75 x [tex]10^{-3}[/tex] mL = .75 x [tex]10^{-3}[/tex] x 1000 µL
= 0.75 µL
4.11 x [tex]10^{-4}[/tex] dL = 4.11 x[tex]10^{-4 }[/tex]x 100 mL
= 0.0411 mL
= 41.1 µL
325 µL > 41.1 µL > 0.75 µL
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What are electrolytes?
Answer:
Electrolytes are minerals in your body that have an electric charge. They are in your blood, urine, tissues, and other body fluids. Electrolytes are important because they help. Balance the amount of water in your body
Explanation:
Two particles of the element iodine are chemically bound. The two particles compose what?
Group of answer choices
a compound
a molecule
an isotope
an atom
Answer:
compound and elements.
Explanation:
ILL GIVE YOU BRAINLIST !!! HAVE TO GET IT RIGHT !!
1.
Explain.
Identify Which are the quantitative data in the example above?
Answer: The 3rd and 6th bullet point is the quantitative data.
Explanation: Quantitative data is expressed by NUMBERS and Qualitative data is expressed by WORDS. The 3rd and 6th one is correct because they both use numbers to compare how much time hummingbirds spent feeding on nectar.
Suppose that at 9:00 A.M. the temperature of a room is 18°C, and at noon it is 24°C. What was the increase in temperature?____________________________
Answer:what’s the answer
Explanation:
Scientists are studying different jackets made for extremely cold, snowy weather. They are trying to find jackets
that are warm but also thin enough to allow for natural bodily movement.
Which question could the scientists answer scientifically?
Which jacket's color looks the best?
Which jacket traps the most heat?
Would warm and thin jackets cost less?
Which jacket seems the most professional?
jp
Answer:
Which jacket traps the most heat.
Explanation:
I took the test
Answer:
B. Which jacket traps the most heat?
Explanation:
Just got it right on Edg
CH3
/
CH3----C-----CH3
/
CH3
Spell out the full name of compound.
Answer:
A. Neopentane.
B. 2,2-dimethyl-propane.
Explanation:
Hello,
In this case, for the given compound we can spell out two possible names:
A. Neopentane: it is, because the molecule has five carbon atoms wherein there is a central one, bonded to the other four.
B. 2,2-dimethyl-propane: it is, because we find two methyl radicals at the second carbon.
Regards.
Differentiate between a pure substance and a mixture and provide examples
Explanation:
pure substances are those substances which are made up of one elements
mixture that those substances which are made by more than two or three elements
Answer:
Brainliest is appreciated
Explanation:
Substances which have a specific composition and cannot be separated into any constituents are called pure substances. Pure substances are further divided into elements and compounds. The combination of two or more pure substances is called a mixture. Mixtures can be classified into two types viz. heterogeneous and homogeneous mixtures.
EXAMPLES
pure substance
gold, pure water, hydrogen gas
mixture substance
oil and water, sand and sugar
Question 2
5 pts
80) Multiply 6.4 x 10-3 times 8.0 x 10' and express the answer in scientific notation.
O 5.1 x 10-21
O 5.1 x 10-3
O 5.1x 103
O 5.1x 104
0 5.1 x 105
5 pts
Answer:
5.1 x 10⁻¹
Explanation:
Given:
6.4 × 10⁻³ × 8.0 × 10¹
Find:
Value of equation
Computation:
6.4 × 10⁻³ × 8.0 x 10¹
[6.4 × 8.0] × [10⁻³ × 10¹]
[51.2] × [10⁻²]
5.12 x 10⁻¹
5.1 x 10⁻¹ (Approx)
Isotopes are atoms with the SAME number of protons, but DIFFERENT numbers of neutrons. Question 8 options: True False
Answer: The correct answer would be : True
I hope that this helps you !
Which of the following molecules would form a micelle?a. NaClb.CH3COOHc. CH3COO^-NH^4+d. CH3(CH2)^10COO^-Na^+e. CH3(CH2)^10CH3
Answer:
CH₃(CH₂)₁₀COONa
Explanation:
The compounds given are
NaCl
CH₃COOH
CH₃COONH₄
CH₃(CH₂)₁₀COONa
CH₃(CH₂)₁₀CH₃
CH₃(CH₂)₁₀COONa will form micelle . Micelle are formed by soap solution which helps in the removal of oily dirt from our clothes . They are spherical shaped tiny droplet of oil which contains the tail of long chain organic compound like salt of long chain fatty acids . The surface of the droplet is lined with the tip of the chain which consists of negative charge of the tail end . On the average , each micelle contains a specific amount of charge . Due to it , they make colloidal solution in the water and gets washed off my water . The oily dirt is thus removed .
CH₃(CH₂)₁₀COONa ⇄ CH₃(CH₂)₁₀COO⁻ + Na⁺
CH₃(CH₂)₁₀COO⁻ part which is long chain of fatty acid gets adsorbed by oily droplet formed by oily dirt and forming micelle .
the box's volume is 42cm3 and the mass is 20g what is the density?
Answer:
0.5g/cm^3
Explanation:
Density = Mass / Volume
Density = 20g / 42cm^3
Density = 0.476g/cm^3
note*: round to the nearest sigfig
Answer is: 0.5g/cm^3
The box's volume is 42cm³ and the mass is 20g then the density is 0.5g/cm³.
What is density ?
The mass of a substance per unit of volume is its density. Density is most frequently represented by the symbol, however the Latin letter D may also be used. Density is calculated mathematically by dividing mass by volume.
How much "stuff" is contained in a specific quantity of space is determined by its density. For instance, a block of the harder, lighter element gold (Au) will be denser than a block of the heavier element lead (Pb) (Au).
Because it enables us to predict which compounds will float and which will sink in a liquid, density is a crucial notion. As long as an object's density is lower than the liquid's density, it will often float.
Density = Mass ÷ Volume
Density = 20g ÷ 42cm³
Density = 0.476g/cm³
= 0.5g/cm³
Thus, the density is 0.5g/cm³.
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6. What effect does an increase in blood hydrogen ion levels have on the pH of the blood?
Answer: the two parameters change inversely; as hydrogen ion concentration increases, pH falls. due to the logarithmic relationship, a large change in hydrogen ion concentration is actually a small change in pH. For example, doubling the hydrogen ion concentration causes pH to fall by just 0.3.
A sample of mass 6.814 grams is added to another sample weighing 0.08753 grams.
The subsequent mixture is then divided into exactly 3 equal parts. One of those parts has the yield multiplied by 7.6335 times; what is the final mass?
Answer:
17.5609grams
Explanation:
According to the question, a sample of mass 6.814 grams is added to another sample weighing 0.08753 grams i.e.
= 6.814 + 0.08753
= 6.90153 grams
The result of this mixture i.e. 6.90153 grams is divided into three equal parts i.e.
= 6.90153 ÷ 3
= 2.30051 grams
This means that each equal part weighs 2.30051 grams
One of the yield (2.30051 grams) is multiplied by 7.6335 times i.e.
= 2.30051 × 7.6335
= 17.56094309
Hence, the final mass is 17.5609grams
How do vapors and gases differ
Answer:
Difference between Vapor and Gas
Usually, a vapour phase consists of a phase with two different substances at room temperature, whereas a gas phase consists of a single substance at a defined thermodynamic range, at room temperature
Explanation:
If hydroxide is added to an amino acid, how will this affect the charge on the amino acid?
Answer:
The amino acid will become more negatively charged
Explanation:
Amino acids are organic compounds containing the positive amine (-NH₂) group which is the basic group, and the negative carboxylic (-COOH) group, which is the acidic group. Because they contain both acidic and basic groups with a positive and negative charge that do not contain an overall electric charge, they are known as zwitterions. They are the smallest units of a protein molecule.
When a hydroxide group is added to an amino acid, the PH is increased, and the hydrogen ion on the amine (NH₃+) is removed, making the compound to have an overall negative charge, hence it is no longer a zwitterion.
[tex]\chemfig{N H_3^+-R-CH-COO^- + OH^- \longrightarrow \chemfig{N H_2-R-CH-COO^- + H_2O[/tex]
notice that the amino group has a net negative charge on the product side of the reaction
The addition of hydroxide to an amino acid affects the charge on the amino acid as it will become more negatively charged.
It will become more negatively charged.
Amino AcidWhen placed in an electromagnetic field, the physical attribute of matter known as electric charge causes it to experience a force.
A positive or negative electric charge can exist. Amino acids are chemical molecules made up of amino and carboxylate. Hydroxide is a polyatomic ion made up of two elements: oxygen and hydrogen.
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(3.0 x 10^8) / (5.76 x 10^14 s-1)
Answer:
521 nm
Explanation:
The following data were obtained from the question:
Frequency (f) = 5.76×10¹⁴ s¯¹
Wavelength (λ) =?
Velocity (v) , wavelength (λ) and frequency of a wave are related according to the following equation:
Velocity (v) = wavelength (λ) × frequency (f)
v = λf
With the above equation, we can obtain the wavelength of the photon of the green light as follow:
Frequency (f) = 5.76×10¹⁴ s¯¹
Velocity of light (v) = 3×10⁸ m/s
Wavelength (λ) =?
v = λf
3×10⁸ = λ × 5.76×10¹⁴
Divide both side by 5.76×10¹⁴
λ = 3×10⁸ / 5.76×10¹⁴
λ = 5.21×10¯⁷ m
Finally, we shall convert 5.21×10¯⁷ m to nanometer (nm).
This can be obtained as follow:
1 m = 1×10⁹ nm
Therefore,
5.21×10¯⁷ m = 5.21×10¯⁷ × 1×10⁹
5.21×10¯⁷ m = 521 nm
Therefore, the wavelength (λ) of the photon of the green light is 521 nm
Which of the following is NOT a "weak" interaction?
a. hydrogen bonds b. van der Waals forces c. disulfide bonds d. ionic interactions e. hydrophobic interactions
Answer:
D.ionic interaction is a strong interaction
When atoms come close enough to one another, an ionic connection is created. Atoms can interact with one another ionically, and this distance is greater than the bonding distance. Therefore, option D is correct.
What is ionic interaction ?The main interaction taking place in ionic compounds is ionic bonding, a form of chemical bonding that includes the electrostatic attraction between two atoms or ions with dramatically differing electronegativities.
Ions with opposing charges are drawn to one another through ion-ion interactions. They are also known as ionic bonds, because they are what keep ionic compounds together. opposing charges attract each other whereas like charges repel each other.
The whole transfer of valence electrons between atoms is referred to as an ionic bond. It is a kind of chemical connection that produces two ions with opposing charges. In ionic bonding, the nonmetal receives the electrons to become a negatively charged anion while the metal gives them up to become a positively charged cation.
Thus, option D is correct.
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What causes blood cells to shrink?
The work needed to move a mass of 2.12 kg 47.1 m against a resistive force of 21.4 N is ___ J.
Answer:
1007.94 J
Explanation:
Work done: This can be defined as the product of force and distance, along the direction of the force. The S.I unit of work is Joules (J) .
Form the question above,
W = F×d........................... Equation 1
Where W = Work done, F = Resistive force, d = distance.
Given: F = 21.4 N, d = 47.1 m
Substitute these values into equation 1
W = 21.4(47.1)
W = 1007.94 J
The density of ethanol is 0.789 g/mL at 200 C. What is the mass of a sample of ethanol, at this temperature, that has a volume of 175.0 mL?
Answer:
D d
Explanation:
What is a observation
Which of the following compounds will not possess dipole dipole interactions between its molecules?A. HBr.B. CO2.C. PH.D. NO.E. SCl.
Answer:
B. CO2
Explanation:
Because its a neutral compound hence lacks any form of dipole dipole interaction
Dr. Winters decides not to tell the people in his experiment about the potential risks. He
.
A) is within the limits of ethical behavior
B) is being noncompliant
C) is making an honest mistake
D) has a lot of integrity
Answer: sorry I cant help you I need the same answer
Explanation:
Answer:
b
Explanation: