Answer:
a
Explanation:
a
Classify the following as either an element, compound, homogeneous mixture or
heterogeneous mixture:
sodium chloride
Sodium chloride is the chemical name for salt and is composed of sodium and chlorine, so it is a compound.
1L = 1000 mL
Molarity (M) = moles of solute / L of solution
Calculate the moles of NaCl required to prepare 250 mL of 1.5 M aqueous solution.
Answer:· 44 g NaCl Explanation: The problem provides you with the molarity and volume of the target
Explanation:
Boyle's Law states that when a sample of gas is compressed at a constant temperature, the pressure P and volume V satisfy the equation PV = C, where C is a constant. Suppose that at a certain instant the volume is 300 cm3, the pressure is 180 kPa, and the pressure is increasing at a rate of 30 kPa/min. At what rate is the volume decreasing at this instant?
Answer:
The gas is decreasing at a rate of 50 cubic centimeters per minute.
Explanation:
The Boyle's Law is represented by the following expression:
[tex]P\cdot V = k[/tex] (1)
Where:
[tex]P[/tex] - Pressure, in kilopascals.
[tex]V[/tex] - Volume, in cubic centimeters.
[tex]k[/tex] - Proportionality constant, in kilopascal-cubic centimeters.
By definitions of rate of change and implicit differentiation, we derive the following differential equation:
[tex]\dot P \cdot V + P\cdot \dot V = 0[/tex] (2)
Where:
[tex]\dot P[/tex] - Rate of change of the pressure, in kilopascals per minute.
[tex]\dot V[/tex] - Rate of change of the volume, in cubic centimeters per minute.
Then, we clear the rate of change of the volume within (2):
[tex]P\cdot \dot V = -\dot P\cdot V[/tex]
[tex]\dot V = -\left(\frac{\dot P}{P} \right) \cdot V[/tex]
If we know that [tex]P = 180\,kPa[/tex], [tex]\dot P = 30\,\frac{kPa}{min}[/tex] and [tex]V = 300\,cm^{3}[/tex], then the rate of change of the volume is:
[tex]\dot V = -\left(\frac{\dot P}{P} \right) \cdot V[/tex]
[tex]\dot V = -50\,\frac{cm^{3}}{min}[/tex]
The gas is decreasing at a rate of 50 cubic centimeters per minute.
Exit ticket: Name the 2 factors that Terrestrial Biomes are separated by ___________ & ________
Answer:
temperature and rainfall
Explanation:
Two trials are run, using excess water. In the first trial, 7.8 g of Na2O2(s) (molar mass 78 g/mol) is mixed with 3.2 g of S(s). In the second trial, 7.8 g of Na2O2(s) is mixed with 6.4 g of S(s). The Na2O2(s) and S(s) react as completely as possible. Both trials yield the same amount of SO2(aq). Which of the following identifies the limiting reactant and the heat released, q, for the two trials at 298 K?
Limiting Reactant q
A. S 30. kJ
B. S 61 kJ
C. Na2O2 30. kJ
D. Na2S2 61 kJ
Answer:
The answer is "Option C".
Explanation:
Given equation:
[tex]2Na_20_2 (s)+S(s)+2H_2O \longrightarrow 4NaOH(aq)+SO_2(aq)[/tex]
[tex]\to \Delta H^{\circ}_{rxn} (298\ K) = -610 \frac{kJ}{mol}[/tex]
[tex]\to Na_2O_2 \ Mass = 7.8 \ g\\\\ \to Na_2O_2 \ Molar \ mass = 78 \frac{g}{mol}[/tex]
[tex]Na_2O_2[/tex] Has been the reactant which is limited since the two experiments are equal to[tex]Na_2O_2[/tex] for relationship between stress amounts.
[tex]Na_2O_2, n =\frac{Mass of Na_2O_2}{Molar mass of Na_2 O_2}=\frac{7.8 \ g}{78 \frac{g}{mol}} =0.1 \ mol \\\\q=\Delta H^{\circ}_{rxn} \times n = \frac{ -610 \ kJ}{ 2 \ mol \ Na_2 O_2} \times 0.1 \ mol \ Na_2O_2= 30.5 \ KJ\\\\[/tex]
Limiting reactant =[tex]Na_2O_2[/tex]
[tex]q=30.5 \ kJ \approx 30 \ kJ[/tex]
Choose the best answer
1. Gas A diffuses twice as fast as another gas B. If the density of the gas A is 2, the molecular mass of
(a)2
(b) 4
(c) 8
(d) 16
i think it is
(b) 4
:) hope its correct :)
Which rank was NOT included in Linnaeus' taxonomy?
Kingdom
Family
Domain
Order
Answer:
Domain
Explanation:
This is because Linnaeus taxonomy is a system of classification which was invented by a swedish Botanist called Carl Linnaeus and it is refered to hierarchy of grouping organisms called taxa. It involve 7 system of classifications and they include Kingdom, Phylum, Class, Order, Family, Genus, and Species.
If 0.000066 moles of 0.01 M solution of carbonic acid dissociates, then what is Ka of carbonic acid
Answer: 4.4 x 10^-7
Explanation:
0.000066 x 0.0000066 / 0.01
= 4.4 x 10^-7
Which compound is the conjugate base in the following reaction :H2SO4 + H2O —> HSO4 + H30+
*☆*――*☆*――*☆*――*☆*――*☆*――*☆*――*☆*――*☆**☆*――*☆*――*☆*――*☆
Answer: HSO4-
Explanation:
I hope this helped!
<!> Brainliest is appreciated! <!>
- Zack Slocum
*☆*――*☆*――*☆*――*☆*――*☆*――*☆*――*☆*――*☆**☆*――*☆*――*☆*――*☆
You have three containers each of which is connected to a fourth empty container. Three of the containers contain pure gases. In the first container oxygen is at 2 atm, nitrogen at 4 atm is in the second container, and argon at 1 atm is in the third. When you open the valve and mix the gases in the forth container, what is the pressure, PT, in the forth container
Answer: The total pressure is 7 atm
Explanation:
According to Dalton's law, the total pressure is the sum of individual pressures.
[tex]p_{total}=p_A+p_B+p_C...[/tex]
Given : [tex]p_{total}[/tex] =total pressure of gases = ?
[tex]p_{O_2}[/tex] = partial pressure of oxygen = 2 atm
[tex]p_{N_2}[/tex] = partial pressure of nitrogen = 4 atm
[tex]p_{Ar}[/tex] = partial pressure of argon = 1 atm
putting in the values we get:
[tex]p_{total}=2atm+4atm+1atm[/tex]
[tex]p_{total}=7atm[/tex]
Thus the total pressure is 7 atm
help people i really need this
What is thePercent composition of dichlorine heptoxide?
Answer:
The percent composition of dichlorine heptoxide is 38.76% CI and 61.24% O
Answer:
38.76%cl and 61.24%o
Explanation:
the percent composition of dichlorine heptoxide is 38.76%Cl and 61.24%O
What is a hot spot? Must be in your own words ( please hurry)
Answer:
It depends. what hot spot are you looking for?
Answer:
A hot spot is an area on Earth over a mantle plume or an area under the rocky outer layer of Earth, called the crust, where magma is hotter than surrounding magma. The magma plume causes melting and thinning of the rocky crust and widespread volcanic activity.
Explanation:
Hope this is what you mean be hot spot!
I hope this helps you!
When one gram of liquid water at its boiling point is changed into water vapor
1.
334 J/g is gained from the surrounding environment
2.
334 J/g is released into the surrounding environment
3
2260 J/g is gained from the surrounding environment
4
2260 J/g is released into the surrounding environment
Answer: 2260 J/g is gained from the surrounding environment
When one gram of liquid water at its boiling point is changed into water vapor, 2260 J/g of energy is gained from the surrounding environment.
What is heat of vaporization?Heat of vaporization is the amount of heat that is required by any body during their transition process from liquid state to vapor state, at a particular temperature i.e. no change in temperature during whole process.
During the transition of one gram of liquid water into water vapor at its boiling point of 100°C, 2260 J/g energy is absorbed by the water for the formation of vapor.
Hence, option (3) is correct.
To know more about heat of vaporization, visit the below link:
https://brainly.com/question/26306578
Consider the fatty acid. A carboxylate salt is attached to a 19 carbon chain, where double bonds are present between carbons 5 and 6, between carbons 8 and 9, between carbons 11 and 12, and between 14 and 15. The carboxylate carbon is carbon 1. All double bonds are cis. Which of the designations are accurate for the fatty acid
Answer:
ω-3 fatty acid and 19:4(Δ5,8,11,14)
Explanation:
From the image attached below:
We can see the structure of the delta nomenclature showing the numbers of carbons, numbers of double bonds, and the locations of the double bonds in the structure of the carboxylate salt.
Also, we can see the structure of the fatty acid where; the location of the first double bond from the methyl end is shown.
Hence, the designation which are accurate for these structures are:
ω-3 fatty acid and 19:4(Δ5,8,11,14)
5
Select all the correct answers.
Which sentences describe chemical changes?
The temperature of water rises when heated.
When mixed, water and limestone give off heat.
A mixture of red paint and green paint becomes black.
On adding yellow turmeric to a transparent soap solution, the mixture turns bright red.
When ground into powder, grains of wheat become flour.
Answer: The answers are:
When mixed, water and limestone give off heat.
On adding yellow turmeric to a transparent soap solution, the mixture turns bright red.
Solubility is the mass in a given volume of a substance.
True
False
Answer: True
Explanation:
what does pen mean?.
Answer:
P = protons
E = electrons
N = neutrons
remember protons and neutrons (protons are positive and neutrons are neutral as you can already tell by their names) are found at the centre of the nucleus (positive mass). Whilst the electrons (negative) orbit around the shells
Predict the product of this reaction
Al(s) + N2(g)—->
A scientist places 10 ml of water in a test tube and heat it with flaming burner for 2 minutes. The liquid boils and escapes as a steam. This experiment is a good example of a
A chemical change
B physical change
C chemical property
D physical property
Rank the following compounds in order of increasing solubility in water. Items (4 items) (Drag and drop into the appropriate area) No more items Items in order most soluble CaO BaO KCI KI
I have tried CaO> BaO > KCl > KI, this is incorrect.
Answer:
CaO < BaO < KCl <KI
Explanation:
Let us remember that the solubility of an ionic substance in water depends on the magnitude of the lattice energy and the hydration energy. If the hydration energy is equal to or is greater than the lattice energy, the substance dissolves in water.
However, the lattice energy depends on the size of the ions. The smaller the ions in the ionic compound, the higher the lattice energy and the lesser the solubility of the ionic compound.
KI has the least lattice energy and the highest solubility in water while CaO has the highest lattice energy and the least solubility in water.
Uranium, an important component of both nuclear weapons and nuclearreactors, has two major isotopes, U-238, which has a half-life of approximately billion years, and U-235, which has a half-life of approximately million years. Both were present in equal amounts at the time of thecreation of the Earth, billion years ago. How many years after the creationof the Earth had the amount of radiation from uranium decayed to half theamount present at the time of the creation of the Earth
Answer:
Hello your question is poorly written below is the well written question
Uranium, an important component of both nuclear weapons and nuclear reactors, has two major isotopes, U-238, which has a half-life of approximately 4.5 billion years, and U-235, which has a half-life of approximately 700 million years. Both were present in equal amounts at the time of the creation of the Earth, 4.5 billion years ago. How many years after the creation of the Earth had the amount of radiation from uranium decayed to half the amount present at the time of the creation of the Earth
Answer : 140 billion years
Explanation:
Given that :
U-238 h1/2 = 4.5 billion years
U-235 h1/2 = 700 million years
At the beginning both Isotopes where present in equal amount
Determine the T years before the amount of Uranium decays to Half
T = ? N'2 = N1 / 2
we know that N = No ( 1/2 )^h where h = time / half-life time
attached below is the detailed solution of the given problem
Consider the reactivity of phenol, bromobenzene, toluene, and nitrobenzene toward electrophilic aromatic substitution.
The most reactive compound is:_____
because the _______ character of the ______ increases the rate of the reaction.
The least reactive compound is ______
because the _______ character of the ________ decreases the rate of the reaction.
Answer:
The most reactive compound is: Phenol because the electron donating character of the alcohol group increases the rate of the reaction.
The least reactive compound is nitrobenzene
because the electron withdrawing character of the nitro group decreases the rate of the reaction.
Explanation:
PHENOL-: Any of a group of organic compounds with a hydroxyl (OH) group bound to a carbon atom in an aromatic ring is known as phenol. The word phenol is also the basic name for its simplest member, monohydroxybenzene (C6H5OH), also known as benzenol or carbolic acid, in addition to being the common name for the entire family.ELECTRON DONATING CHARACTER-: Via the carbon atom it is bound to, an electron donating group (EDG) has the net effect of increasing electron density in a molecule. EDGs alter a molecule's reactivity by increasing electron density on neighboring carbon atoms: EDGs make nucleophiles stronger.ALCOHOL GROUP-:Each of a class of organic compounds that have one or more hydroxyl (OH) groups bound to an alkyl group's carbon atom (hydrocarbon chain)is called Alcohol. Alcohols are organic compounds of water [tex](H_2O)[/tex] in which one of the hydrogen atoms has been substituted by an alkyl group, which in organic structures is usually expressed by R.NITROBENZENE-:The organic compound nitrobenzene has the chemical formula [tex](C_6H_5NO_2)[/tex]. It's a pale yellow oil that's insoluble in water and smells like almonds. Greenish-yellow crystals form when it freezes. It is made on a wide scale as a precursor to aniline from benzene. It is sometimes used as a solvent in the laboratory, especially for electrophilic reagents.ELECTRON WITHDRAWING GROUP-: An electron withdrawing group (EWG) is a type of group that reduces electron density in a molecule by bonding to a carbon atom. EWGs alter a molecule's reactivity by reducing electron density on neighboring carbon atoms.NITRO GROUP-: The nitro group is one of the most widely used explosophores (functional groups that combine to form a compound explosive). In addition, the nitro group is a heavy electron-withdrawing group. CH bonds alpha (adjacent) to the nitro group may be acidic due to this property.can u identify a chemical equation for the saponification of olive oil as per your experiment?
I
In order to determine the answer to a chemistry problem, a student first converted the given percentages to mole by assuming the sample size was 100 grams. Then the student divide by the smallest mole amount of the elements present. Finally the student used the ratios to write a formula. Which of the following best describes the problem the student likely solved?
a. Determined percent composition
b. None of the above
c. Determining molecular formula
d. Determining empirical formula
Answer: d. Determining empirical formula
Explanation:
Molecular formula is the chemical formula which depicts the actual number of atoms of each element present in the compound.
Empirical formula is the simplest chemical formula which depicts the whole number of atoms of each element present in the compound.
Step 1: If percentage are given then we are taking total mass is 100 grams. So, the mass of each element is equal to the percentage given.
Step 2 : convert given masses into moles
Step 3 : For the mole ratio, divide each value of moles by the smallest number of moles calculated
Step 4: The mole ratio gives the empirical formula of the compund.
im not sure if it is a molecule or an atom
Answer:
the first one
Explanation:
I looked it up:P
Only the 2nd answer is right, uncheck the 1st one
Explanation:
If we had a chemical formula like [tex]3(O_{2} )[/tex] the 3 means there are 3 molecules of [tex]O_{2}[/tex]. The 2 means there are two atoms of oxygen in each molecule.
Ethanol in the body is oxidized to acetaldehyde by liver alcohol dehydrogenase (LADH). Other alcohols are also oxidized by LADH. For example, methanol, which is mildly intoxicating, is oxidized by LADH to the quite toxic product of formaldehyde. The toxic effects of ingesting methanol (a component of many commercial solvents) can be reduced by administering ethanol. The ethanol acts as a competitive inhibitor of methanol by displacing it from LADH. This provides sufficient time for the methanol to be harmlessly excreted by the kidneys. If an individual has ingested 30 mL of methanol (a lethal dose), how much 100 proof whiskey (50% ethanol by volume) must be imbibed to reduce the activity of her LADH towards methanol to 5% of its original value? The adult human body contains ~40L of aqueous fluids throughout which ingested alcohols are rapidly and uniformly mixed. The densities of ethanol and methanol are both 0.79 g/cm3. Assume the KM values of LADH for ethanol and methanol to be 10-3 M and 10-2 M, respectively, and that Ki = KM for ethanol
Answer: The changes are the mL of methanol ingestion (30mL) and the proof of the whiskey (40% ethanol; 80 proof), and the percentage of reduction (1%). I applied the formulas from the last post in reference to this question but am completely lost. The formulas used last time were: 2. Formulas Applied alpha=1 + ([etOH]/KetOH) (V[meOH]/V[etOH])= (Vmax*[meOH]/KmeOH+[meOH])/(Vmax*[meOH]/alpha*KmeOH+[meOH]) which reduces to (V[meOH]/V[etOH])=(alpha*KmeOH+[meOH])/(KmeOH+[meOH]) 3. My attempt Molarity of methanol: 30mL; which equates to 23.7g of methanol; in 40L that is equal to 0.5925 g/L Dividing the molecular weight by 32.04g/mol I get 0.0184925 which is approximately 0.02M; Km is 0.01M Since the molar mass of methanol and ethanol are two fold, I can multiply the g/l by 4. However, unlike the previous problem, I cannot multiply by 2 because I do not have 50% EtOH, so because 40 is less than 50 I assume to multiply by 2.5 yielding: (30mL)(4)(2.5)=300mL 300mL of EtOH to effectively reduce the Methanol to 1%.
Please help I have no idea where to start
Answer:
Download Ptable, it will show all of the elements, and you can click on them, and it will show all the information you need about them!
Explanation:
I hope this helps!!!!!
when are igneous rocks formed?
A. When layers of mud form inside Earth
B. When layers of mud are compressed
C. When melted rock solidifies
D. When solid rock melts
Answer:
C. When melted rock solidifies.
During a dry compression test, the first puff of the test shows 50 PSI and the maximum reading after 4 strokes is 150 PSI. This indicates A. that the cylinders are good. B. weak piston rings. C. a bad spark plug. D. a hole in the piston.
One of the basic engine-diagnostic procedures that can be run is an engine compression test. All of the cylinders must have the same compression for the engine to run smoothly. There are just three possible ways for air to leak out of an engine and cause compression loss.
Exhaust or intake valve Engine rings (or piston, if there is a hole) An engine's head gasketThe procedures for conducting a compression testThe engine should be warmed to its typical operating temperature before testing in order to achieve the best results. The following procedures should be followed for an accurate compression test:
STEP 1: Dispose of each spark plug. As a result, the engine can be turned up to the same speed. Label all spark plug wires accurately.STEP 2 is to block the throttle open. This enables the engine to pull in the most air possible. Additionally, this step guarantees reliable compression test results.STEP 3 After inserting a compression gauge into a spark plug hole, start the engine. Four compression strokes of engine cranking should be performed in total. A puffing sound is produced after each compression stroke.EXAMPLE-If the ultimate, maximum value is 150 PSI, for instance, the reading following the first puff should be greater than 75 PSI. Low first-puff readings could be a sign of weak piston rings.STEP 4 Keep track of the highest readings, then compare the outcomes.Learn more about compression test here https://brainly.com/question/13274092
#SPJ2
