Answer:
the answer is D
Explanation:
Answer; 4
is the atomic mass
The SI unit of length equal to the distance light travels in a vacuum in 1/299 792 458 of a second is the ___.
Answer:
Meter.
Explanation:
Hello,
In this case, The SI unit of length equal to the distance light travels in a vacuum in 1/299 792 458 of a second is the meter as the physical standard used to establish such length.
Regards.
Determine which molecules are weak acids and weak bases, and place them in the appropriate category.
Answer:
[tex]CH_{3} COOH[/tex] is a weak acid with a strong conjugate base [tex](CH_{3} CO_{2} ^{-} )[/tex][tex]CH_{3} NH_{2}[/tex] is a weak base with a strong conjugate acid [tex](CHx_{3} NH_{2} ^{-} )[/tex]Explanation:
Weak acids do not completely dissociate in water to its distinctive ions, but instead forms conjugate bases; and ice versa with weak bases. The conjugate base has strong affinity for protons and vice versa.
I hope you found this explanation clear and easy to follow.
Place the following elements in order of increasing electronegativity.K Cs PA. K < P < CsB. P < Cs < KC. Cs < K < PD. P < K < CsE. Cs < P < K
Answer:
C. Cs < K < P
Explanation:
Electronegativity is the basically the tendency of an atom to attract electrons. The pauling scale is used to quantify electronegativity, the most electronegative element; fluorine has a value of 4.0 and francium, the least electronegative element has a value of 0.7
The electronegative values of the following elements are given as;
K = 0.82
Cs =0.79
P = 2.19
Arranging in order of increasing electronegativity, we have;
Cs < K < P. The correct option is;
C. Cs < K < P
what's the amount of solute in 1.75 L of 0.25 M HCl?
Answer: 0.4375 mols of solute
Explanation:
The problem is asking for the amount of solute. We are given the value of molarity. The molarity is 0.25M. We know that molarity is [tex]M=\frac{mols of solute}{liters of solution}[/tex]. Since we are given the liters of solution is 1.75, we can use those values to solve for mols of solute.
[tex]0.25M=\frac{x}{1.75L}[/tex] [multiply both sides by 1.75 L]
[tex]x=0.4375 mols[/tex]
There are 0.4375 mols of solute.
Compare and contrast the characteristics of metals and nonmetals.
Imagine that you are in the laboratory and your classmate gets a chemical
in their eyes. What would you do?
The insoluble salts below are put into 0.10 M hydrochloric acid solution. Do you expect their solubility to be more, less, or about the same as in a pure water solution?
1. Zinc sulfide
2. Silver chloride
3. Lead iodide
4. Silver hydroxide
Answer:
Zinc sulfide- more soluble in 0.10 M hydrochloric acid solution
Silver chloride- less soluble in 0.10 M hydrochloric acid solution
Lead iodide- same solubility in 0.10 M hydrochloric acid solution as in pure water
Silver hydroxide- same solubility in 0.10 M hydrochloric acid solution as in pure water
Explanation:
Solubility refers to the amount of a substance that dissolves in 1 dm^3 of solvent. Several factors influence the dissolution of solutes in a given solvent. Some substances dissolves at a low pH (in acid solutions) while other dissolve at a low pH (in basic solutions).
For Silver chloride, its solubility decreases in 0.10 M hydrochloric acid solution because of common ion effect when compared to its solubility in pure water.
what is organic chemistry
Answer:
Organic chemistry is what people call a 'branch' of chemistry that studies the structure, properties, and reactions of organic compounds. These contain carbon in covalent bonding.
which of the following best describes precision
Answer:
Good precision because he is hitting the same spot 3 times but we don't know if he is accurate. SO the answer is 2
Phenolphthalein is used as an indicator for basic solutions in the electrolytic cell that's used to split water into its elements. Around which electrode would the solution turn pink?
Answer:
Anode
Explanation:
In the electrolysis of acidified water;
Anode half reaction;
4OH^-(aq)-----> 2H2O(l) + O2(g) + 4e
Cathode half reaction;
4H^+(aq) + 4e ----> 2H2(g)
Phenolphthalein has a pink colour in a neutral medium. A neutral medium in this electrolysis is one in which the hydroxide ion is reduced to water and oxygen and this occurs at the anode hence this is the electrode around which the solution will turn pink.
The pH of a 0.30 M solution of a weak acid is 2.67. What is the Ka for this acid?
A) 4.4 X10^-4
B) 6.6 x10^-4
C) 1.5 x10^-4
D) 2.1 x 10^-4
E) None of the above
Answer:
Ka → 1.5×10⁻⁵
Option E. None of the above
Explanation:
We propose the reaction of equlibrium
Weak ac.H + H₂O ⇄ Weak ac⁻ + H₃O⁺
Initially we have 0.30 moles of acid in 1 L
In equilibrium we would have:
Weak ac.H + H₂O ⇄ Weak ac⁻ + H₃O⁺
0.30 - x x x
We have the pH, where we can obtanined the x, the [H₃O⁺] in the equilibrium.
pH = - log [H₃O⁺] → [H₃O⁺] = 10^⁻(pH)
[H₃O⁺] = 10⁻²'⁶⁷ = 2.14×10⁻³
So let's determine the concentration of the acid, in the equilibrium
0.30 - 2.14×10⁻³ = 0.29786 → [Weak ac.H]
2.14×10⁻³ → [H₃O⁺] = Conjugate base (Weak ac.⁻)
Let's make the expression for Ka
Ka = [Weak ac.⁻] . [H₃O⁺] / [Weak ac.H]
Ka = x² / 0.30 - x
Ka = (2.14×10⁻³)² / 0.29786 → 1.5×10⁻⁵
What is the periodic table?
A. An arrangement of the known elements
B. A table of when elements were discovered
C. A list of major accomplishments in science
D. A timetable of advancements in chemistry
A sample of ozone gas occupies 225 mL at 1.00 atm and 0 °C. If the volume of the gas is 625 mL at 25 °C, what is the pressure?
Answer:
[tex]P_2=0.393atm[/tex]
Explanation:
Hello,
In this case, we can use the combined ideal gas law in order to analyze its behavior as a function of changing temperature, volume and pressure:
[tex]\frac{P_1V_1}{T_1} =\frac{P_2V_2}{T_2}[/tex]
Thus, since we know the volume, temperature and pressure at the initial condition, we can compute the final pressure as shown below:
[tex]P_2=\frac{P_1V_1T_2}{T_1V_2} =\frac{1.00atm*225mL*(25+273)K}{(0+273)K*625mL}\\ \\P_2=0.393atm[/tex]
Regards.
5. When ortho-bromonitrobenzene is treated with NaOH at elevated temperature, only one product is formed. (a) Draw the product. (b) Identify the intermediate formed en route to the product. (c) Would the reaction occur if the starting compound were meta-bromonitrobenzene
Answer:
The product formed is orthonitrophenol
Explanation:
The compound orthonitrophenol is formed when ortho-bromonitrobenzene is treated with NaOH at elevated temperature.
The reaction leads to the formation of an intermediate stabilized by resonance. This intermediate can not be formed by the meta isomer because a resonance stabilized intermediate can not be formed and the product is not stabilized by intramolecular hydrogen bonding hence this reaction will not occur.
what correctly describes a compound in chemistry
Answer:
A chemical compound can be described as substance composed of atoms from more than one element held together by chemical bonds in a fixed stoichiometric proportion. A compound has different physical and chemical properties from its constituent elements. Your welcome! =)
Explanation:
What a good example of hypothesis
Answer:
If you turn the lights on and off rapidly, then the bulb will burn out faster. It's some sort of prediction
Answer:
1. If I replace the battery in my car, then my car will get better gas mileage.
2. If I eat more vegetables, then I will lose weight faster.
3. If I add fertilizer to my garden, then my plants will grow faster.
4. If I brush my teeth every day, then I will not develop cavities.
5. If I take my vitamins every day, then I will not feel tired.
6. If 50 mL of water are added to my plants each day and they grow, then adding 100 mL of water each day will make them grow even more.
Explanation:
Carboxypeptidases can be used to determine the entire sequence of short peptides (<50 amino acid residues) and it starts by reacting with the C-terminal amino acid.
a. True
b. False
Answer:
A. True
Explanation:
Carboxypeptidases are enzymes which function in the digestion of short peptides known as oligopeptides in the small intestine. Oligopeptides contain between 10 to 50 amino acid residues.
The two carboxypeptidases A and B involved in the digestion of proteins in the small intestine are secreted by the exocrine glands of the pancreas.They are both zinc-containing enzymes which remove successive carboxyl-terminal (C-terminal) residues from oligopeptides until free amino acids are obtained.
Since they function in this way, they can be used to determine the entire sequence of short peptides or oligopeptides.
What is an evaluation of work by qualified
people in a field before the work is published.
Answer:
Peer review is the evaluation of work by one or more people with similar competencies as the producers of the work (peers). It functions as a form of self-regulation by qualified members of a profession within the relevant field.
Hope it helped u if yes mark me BRAINLIEST pzllzllzl
Tysm
Let's find the temperature when the pressure is equal to zero. There are two ways of doing this, what are they? What is the temperature when the pressure equals zero? What is the significance of that number?
Answer:
The lower the temperature, the lower the pressure inside of the sphere. If the exact values were plotted out, a linear relationship would be apparent. Extrapolating this line to the point where there would be no pressure yields absolute zero, which is about -273.15 degrees Celsius.
At 570. mmHg and 25 °C, a gas sample has a volume of 2270 mL. What is the final pressure (in mmHg) at a volume of 1250 mL and a temperature of 175 °C?
Answer:
The final pressure is 1556 mmHg
Explanation:
The gas laws are a set of chemical and physical laws that allow determining the behavior of gases in a closed system.
Boyle's law says that "The volume occupied by a given gaseous mass at constant temperature is inversely proportional to pressure" and is expressed mathematically as: P * V = k
Charles's law states that the volume of gas at constant pressure is directly proportional to its temperature and is expressed mathematically as the quotient that exists between the volume and the temperature equal to a constant value:
[tex]\frac{V}{T}=k[/tex]
Gay - Lussac's law states that the pressure of gas at constant volume is directly proportional to its temperature and is expressed mathematically as the quotient between pressure and temperature equal to a constant:
[tex]\frac{P}{T}=k[/tex]
Combined law equation is the combination of three gas laws called Boyle's, Charlie's and Gay-Lusac's law:
[tex]\frac{P*V}{T}=k[/tex]
When you want to study two different states, an initial one and a final one of a gas, it is possible to apply:
[tex]\frac{P1*V1}{T1}=\frac{P2*V2}{T2}[/tex]
In this case:
P1= 570 mmHgV1= 2270 mLT1= 25 C= 298 K (being 0 C= 273 K)P2= ?V2= 1250 mLT2= 175 C=448 KReplacing:
[tex]\frac{570 mmHg*2270 mL}{298 K}=\frac{P2*1250 mL}{448 K}[/tex]
Solving:
[tex]P2=\frac{448K}{1250 mL} *\frac{570 mmHg*2270 mL}{298 K}[/tex]
P2= 1556 mmHg
The final pressure is 1556 mmHg
A ballon at 2.7atm has a volume of 1.6L.What will be the volume if the pressure is reduced to 1,3atm?
Answer:
3.3 L
Explanation:
Step 1: Given data
Initial pressure (P₁): 2.7 atmInitial volume (V₁): 1.6 LFinal pressure (P₂): 1.3 atmFinal volume (V₂): ?Step 2: Calculate the final volume of the balloon
Inside the balloon we have gas. If we consider it behaves as an ideal gas, we can calculate the final volume using Boyle's law.
P₁ × V₁ = P₂ × V₂
V₂ = P₁ × V₁ / P₂
V₂ = 2.7 atm × 1.6 L / 1.3 atm
V₂ = 3.3 L
Question 6 (1 point)
The density of a wood block is 2.58 g/mL. What is the mass of the block if the volume is 13 ml?
Explanation:
Mass = density * volume
Mass of wooden block = 2.58 * 13 = 33.54 g
Mass = density x volume
Mass of wooden block = 2.58 x 13 = 33.54 g
Diethyl malonate (the starting material for the malonic ester synthesis) reacts with bromine in acid-catalyzed conditions to form a product with molecular formula C7H11BrO4. Would you expect this product to be more or less acidic than diethyl malonate?
Answer:
The product would have more acidity than Diethyl malonate
Explanation:
For this question, first, we have to start with the structure of the bromination reaction. The bromination would add a "Br" atom in the middle carbon between the ester groups. Therefore, the molecule produced would be diethyl 2-bromomalonate and the formula of this compound fits with the reported by the question: [tex]C_7H_1_1BrO_4[/tex]
Now, if we have to analyze the acidity we have to check the most acidic hydrogen. In this case, is the "H" in the middle carbon (red hydrogen). In the Diethyl malonate, we have an inductive effect caused by the carbonyl groups on each side of the middle carbon. In the diethyl 2-bromomalonate, we have this same inductive effect plus the Br atom bonded to the same carbon. Therefore, would be easier to remove the hydrogen. So, diethyl 2-bromomalonate would ba more acidity than Diethyl malonate.
See figure 1
I hope it helps!
Express 0.143 s (time is takes light to travel around the world) in scientific
notation.
Your lab partner has carefully measured out 16.50 mL of water. You accidentally tip over the graduated cylinder and spill some of the water. You stand the cylinder up, and determine that there are 8.0 mL of water left. Which measurement is more precise-your lab partner’s or yours? Explain your answer.
Answer:
Explanation:
In the measurement of 16.50 , the measuring scale is capable of measuring upto the depth of 1 / 100th of one mL . But In the measurement of 8.0 , the measuring scale is capable of measuring upto the depth of 1 / 10th of one mL
So the former is more precise because the second scale the measurement beyond 1/ 10 th is made by guesswork which may be faulty . So the former is more precise .
Answer: his lab partner is more precise
Explanation: If the lab partner carefully measured the measurements and the other guy just determined it the lab partner's measurements should be more exact. HOPE THIS HELPS.
Which state in each of the following pairs has the higher entropy per mole of substance?
1. Ice at - 40 degrees C or ice at 0 degrees C.
2. N2 at STP or N2 at 0 degrees C and 10 atm.
3. N2 at STP or N2 at 0 degrees C in a volume of 50 L.
4. Water vapor at 150 degrees C and 1 atm or water vapor at 100 degrees C and 2 atm.
Answer:
1. Ice at 0 degrees C.
2. N₂ at STP.
3. N₂ at STP.
4. Water vapor at 150 degrees C and 1 atm.
Explanation:
First, we need to remember that entropy (S) is a measure of how spread out or dispersed the energy of a system is among the different possible ways that system can contain energy. The greater the dispersal, the greater is the entropy.
When the temperature is increased, the energies associated with all types of molecular motion increase. Consequently, the entropy of a system always increases with increasing temperature.
With this in mind, we consider the pairs:
1. Since the ice at 0ºC has a greater temperature than the ice at -40 ºC, the first has the higher entropy.
2. The N₂ at STP (that is, 1 atm and 25 ºC) has higher entropy than N₂ at 0ºC and 10 atm because it has a higher temperature and less pressure, which allows a greater dispersal of energy by the molecules of the gas.
3. The N₂ at STP has a higher entropy since it has a higher temperature than N₂ at 0ºC, even though it the first has a lower volume (24,4 L vs. 50 L).
4. The water vapor at 150 ºC and 1 atm have a higher temperature and a lower pressure. This means that its molecules will have an increased molecular motion than the molecules of water vapor at a lower temperature and higher pressure. Therefore, the first has the highest entropy.
Which image displays a chemical property about a substance? Choose all that apply
Answer:
Answer: II and IV
Explanation: Flammability and the ability to rust are chemical properties because they change an object. I, III, and V are physical properties because it doesn't change the object's composition. This includes weight, the change in matter (solid to liquid), or change in volume.
Hope this helps!!!
Explanation:
Answer:
Answer: II and IV
Explanation:
Explanation: Flammability and the ability to rust are chemical properties because they change an object. I, III, and V are physical properties because it doesn't change the object's composition. This includes weight, the change in matter (solid to liquid), or change in volume.
Which of the following equations best represents methanol being dissolved in water
A. CH3OH(I) —> CH3+(aq) + OH-(aq)
B. CH3OH(I) —> CH3O-(aq) + H+(aq)
C. CH3OH(I) —> CH3OH(aq)
Answer: [tex]CH_3OH(l)\rightarrow CH_3OH(aq)[/tex]
Explanation:
According to the concept of “Like dissolves like”, the polar solutes dissolve in polar solvents, and non-polar solutes dissolve in non-polar solvents.
Covalent compounds which are formed by sharing of electrons between non metals, when dissolved in water, forms hydrogen bonding with water if they contain a electronegative atom along with hydrogen. Example: methanol [tex](CH_3OH)[/tex]
Ionic compounds which are made up of cations and anions, when dissolved in water, dissociate into ions. Example: [tex]NaCl[/tex]
Thus equation which best represents methanol being dissolved in water is:
[tex]CH_3OH(l)\rightarrow CH_3OH(aq)[/tex]
Identify the formula for an alkyne. Identify the formula for an alkyne. CnH2n 4 CnH2n-2 CnH2n 2 CnH2n-4 CnH2n
Answer:
Option 3: [tex]C_{n} H_{2n-2}[/tex]
Explanation:
Alkynes are of the homologous series of acyclic (alphatic) triple bonded carbon-carbon atoms. The could be branched or unbranched chain, but the triple bonded carbons are ether attached to hydrogen atoms or a single-bond with carbon.
Thus they carry the general formula [tex]C_{n} H_{2n-2}[/tex] across the series; where n is any integer greater than 1. The simplest forms of alkynes are acetylene molecules which have the formula [tex]C_{2} H_{2}[/tex].
I hope this explanation was resourceful and easy to understand.
What evidence of climate change