Answer:
Nocturnal animals, such as owls, tend to have wide pupils and several rod cells in their retina because wide pupil allow more light to enter the eyes and the rods cells in the retina are sensitive to dim light and are vital for night vision.
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:
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 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.
The [Fe(H₂O)₆]³⁺ complex requires a relatively small amount of energy to promote an electron from the t2g to the eg. Based on the UV data, predict the spin of this complex.
Answer:
The spin of the complex is 5.92 B.M
Explanation:
Please see the attachments below
Which of the following would you predict to have the greatest solubility in water?
a. cyclobutane
b. pentane
c propanol C.
d. kexanol
e. ethyl methyl ketone
Draw the d-orbital splitting for an octahedral and a tetrahedral complex.
Answer:
See explanation
Explanation:
In an octahedral crystal field, the metal is at the centre of an octahedron with ligands at the six corners of the octahedron. Approach of the ligand splits the orbitals into higher energy eg and lower energy t2g orbitals. The eg orbitals are 0.6∆o above the bari centre while the t2g orbitals are -0.4∆o below the bari centre.
In a tetrahedral crystal field, the tetrahedral crystal field splitting ∆t= 4/9∆o. In the tetrahedral crystal field, the t2 orbitals are at a higher energy and are +0.4∆t above the bari centre while the e orbitals are at a lower energy and are -0.6∆t below the bari center.
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 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:
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.
How many grams of glucose (C6H12O6, 180.2 g/mol) would be required to prepare 2.00 L of a 0.318 M glucose solution that could be used in an IV bag?
Answer:
115 g
Explanation:
Step 1: Given data
Molar mass of glucose: 180.2 g/molVolume of solution: 2.00 LMolarity of the solution: 0.318 MStep 2: Calculate the moles of glucose
The molarity is equal to the moles of solute divided by the liters of solution.
M = moles of glucose / liters of solution
moles of glucose = M × liters of solution
moles of glucose = 0.318 mol/L × 2.00 L
moles of glucose = 0.636 mol
Step 3: Calculate the mass corresponding to 0.636 moles of glucose
0.636 mol × 180.2 g/mol = 115 g
D= 1.246g/cm3 /(1 +8.324x10^-5 K^-1 T) at what temp (K) will the density of this liquid equal 1.212 g/cm3
Answer:
At 336.6K, the density of the liquid is 1.212g/cm³
Explanation:
The density change in a substance with the temperature. As general (But not always applicable) rule, the density decreases with the temperature.
A formula to find density of the liquid of the problem is:
[tex]D = \frac{1.246g/cm^3}{1+8.324x10^{-5}K^{-1}*T}[/tex]
Where D is density and T is absolute temperature (In K).
If we want a density of 1.212g/cm^3:
[tex]1.212g/cm^3 = \frac{1.246g/cm^3}{1+8.324x10^{-5}K^{-1}*T}\\1.212g/cm^3+1.01x10^{-4}g/cm^3K^{-1}*T = 1.246g/cm^3\\1.01x10^{-4}g/cm^3K^{-1}*T =0.034g/cm^3\\T = 336.6K[/tex]
At 336.6K, the density of the liquid is 1.212g/cm³Biology is based on ___ interactions.
Answer:
Biology is based on organisms interactions
Explanation:
Not sure....if wrong pls correct me
Answer:
organisms
Explanation:
Biology is based on organisms interactions.
The mass of a neutron is equal to the mass of a proton plus the mass of an electron.
A. True
B. False
Answer:
B. False
Explanation:
The mass of a neutron is nearly the same mass of a proton whereas the electron is much less massive.
Exact masses are:
Neutron = 1.6749286x10²⁷ kg
Proton = 1.6726231x10⁻²⁷ kg
Electron = 9.1093897x10⁻³¹ kg
The mass of a proton plus the mass of an electron is:
1.6735340x10⁻²⁷ kg.
This mass is different to the mass of the neutron. Thus, the answer is:
B. FalseExpress 0.143 s (time is takes light to travel around the world) in scientific
notation.
You wish to prepare 222 grams of 22.1 % FeCl2. You will need_______ grams of iron(II) chloride and ________mL of water. Assume that the density of water is 1.00 g / ml
Answer:
I will need 49 grams of iron(II) chloride and 173 mL of water .
Explanation:
222 grams of 22.1 % FeCl₂ will require
222 x 0.221 gram of FeCl₂ and rest will be water .
49 gram of FeCl₂ and 173 grams of water .
density of water is 1.00 g / mL
volume of water in mL = 173 / 1
= 173 mL
Hence I will need 49 grams of iron(II) chloride and 173 mL of water .
Answer:
same
Explanation:
confused
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
Which of the following is not a reason why organic structures promote innovation?
A) high formalization
B) low vertical differentiation
C) high flexibility
D) low centralization
E) cross-fertilization
Answer: Option A.
high formalization
Explanation:
High formalization is not a reason organic structures promote innovation because formalization refers to written rules, regulations, policies or descriptions of organic structures and it is not a reason to promote innovation of organic structures because there will be continual manner of structure behavior and there will be reduced motivation.
Glucose and amino acids are reabsorbed from the glomerular filtrate by the __________.
Answer:
Amino acids, along with glucose, are reabsorbed in the glomerular system with a passive or active mechanism as the fluid travels through the entire renal tubular system and enters the circulation again.
Active mechanisms are those that require expenditure of energy, that is, expenditure of the energy currency, while the passive ones do not, they occur through spontaneous non-energy processes such as osmosis, the osmotic gradient and the difference in concentrations in different compartments.
Explanation:
Glomerular filtration is the regulator of the excretion of metabolites and toxic molecules or not necessary for our body. That is why if the amino acid values are high as well as those of glucose in urine, we will be facing a pathology.
If glucose is increased, it is because there is a glycemic peak in blood volume, hence possible diabetes.
And if the amino acids are increased, we could be facing an autoimmune or proteolytic pathology where a large amount of body proteins such as muscle proteins would be breaking down and releasing the amino acids that make it up, this phenomenon usually appears in those people who suffer from rhabdomyolysis in expenses very intense energy sources not appropriate.
On the other hand, glomerular filtration occurs in the kidney and is carried out by the nephron, which is the functional unit of the kidney, within it there is a specific tubular system in collection, absorption and reabsorption, added to the presence of Bowman's capsule.
Which of the following was not a way that American colonists reacted to British taxes?
Staged protests outside of the Parliament building
Formed secret societies to discuss independence from Great Britain
Made their own goods to avoid buying imports
Sent formal requests to the king asking him to remove the charges
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!
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.
Which one of the following reactions would produce t-butyl methyl ether in high yield?
A) t-butyl chloride + sodium methoxide
B) t-butanol + methanol in presence of H2SO4 at 140 C
C) t-butyl bromide + bromomethane in presence of NaOH
D) sodium t-butoxide + bromomethane
Answer:
D) sodium t-butoxide + bromomethane
Explanation:
The alkoxide ion is a strong nucleophile, that unlike alcohols, will react with primary alkyl halides to form ether. This general reaction is known as the Williamson synthesis, and is a SN₂ displacement. The alkyl halide must be primary so the back side attack is not hindered, and the alkoxide ion must be formed with the most hindered group.
The mechanism can be seen in the attachment.
The reaction of sodium t-butoxide and bromomethane gives the higher yield. Thus, option D is correct.
For the production of t-butyl methyl ether in higher yield, there has been the Williamson ether synthesis. The synthesis has been carried out with the reaction of alkylhalide with the alkoxide, that results in the formation of an ether.
The Williamson reaction has been a SN2 reaction that has been carried out in two steps with the addition of nucleophile and removal of the halide for the formation of ether.
From the given reactants, the higher yield has been obtained with the reaction of alkoxide and alkyl halide. Thus, reaction of sodium t-butoxide and bromomethane gives the higher yield. Thus, option D is correct.
For more information about the Williamson synthesis, refer to the link:
https://brainly.com/question/14491871
Why don’t the trees spontaneously catch fire and burn all the time? Why don’t the fires stop immediately as soon as they start?
Answer:
Both of these phenomena is due to the ignition temperature.
Explanation:
Trees don't spontaneously catch fire because there is a temperature above which materials combust. This is called the "ignition temperature." This temperature must be reached before the trees will ignite, and the external condition does not always harbor such high temperature.
Fires don't stop immediately because, while some parts of the flame has cooled down sufficiently below the ignition temperature, other parts of the flame have not. It takes time for all the part of the flame to cool down below ignition temperature for the burning to stop.
These are all due to the ignition temperature.
The ignition temperature is defined as the temperature at which a substance begins to burn spontaneously.
The ignition temperature of a woody material is about 343 °C (650 °F). This ignition temperature is much higher than ambient temperature hence trees don't spontaneously catch fire and burn all the time.
Also, all the parts of the burning fire are not at the same temperature. Some parts may cool below the ignition temperature quicker than other parts of the flame hence the fires don't stop immediately as soon as they start.
Learn more; https://brainly.com/question/13048470
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
In an electron-dot symbol of an element, the dots are used to represent ________.
Answer:
Valence electrons.
Explanation:
Hello,
In this case, the electron dot structure is widely known for representing the valence electrons as dots placed around the chemical symbol and they are defined as the electrons configured at the outermost shell of the studied atom. Commonly, electrons are placed up to two on each side of the elemental symbol for a maximum of eight. For instance, sodium has one valence electron, sulfur has six valence electrons, helium has eight valence electrons and so on. Valence electrons are known to be dependent of the electron configuration.
Best regards.
Imagine that you are in the laboratory and your classmate gets a chemical
in their eyes. What would you do?
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.
How does work affect energy between objects so it can cause a change in the form of energy?
Order the materials from smallest refractive index to largest refractive index.
a. Air
b. Diamond
c. Glass
d. Quartz Water
Answer and Explanation:
The refractive index states that the incidence angle sine to refraction angle sign
Now, According to the given situation, the manner that the materials from the smallest refractive index to the largest refractive index is presented below:-
Air = 1
Water = 1.33
Glass = 1.52
Quartz = 1.46
Diamond = 2.42
From the above we can find the sequence that is
[tex]Air<Water<Quartz<Glass<Diamond[/tex]