Please select the word from the list that best fits the definition
Represents a range of responses to a question:
Caption
Legend/Key
Scale
Answer:
The answer is B(scale)
Explanation:
Since the question asked about a range, the scale would be the most logical answer since scales are used to measure.
Answer:
the answer is C.
Explanation:
PLS PLS PLS PLS PLS PLS PLS help ASAP!!!!! Scientists call all of the compounds that contain carbon and are found in living things Organic because ________.
WILL DO BRAINLIEST!
Explain how this chemical equation demonstrates the Law of Conservation of Matter (Mass).
Answer:
Explanation:
The equation must be balanced on both sides to show the law of conservation of mass. So, as long as it is equaled, the law is shown.
A solution in which the pH is 1.6 would be described as
a.
very acidic
b.
slightly acidic
c.
very basic
d.
slightly basic
e.
neutral
Answer:
a. very acidic
Explanation:
A solution with a pH of 1.6 would be described as a very acidic solution.
The pH scale is a convenient scale for expressing the level of acidity or alkalinity of aqueous solutions.
The scale ranges from 1 to 14 in which case 1 is the lower limit and 14 the upper limit.
An acidic solution has a pH value less than 7. As pH decreases, the acidity of the solution increases. Neutral solutions have a pH of 7An alkaline solution has a pH greater than 7 and the level of alkalinity increases as pH increases.What is the pH of a solution made by mixing 0.050 mol of NaCN with enough water to make a liter of solution
Answer:
pH = 11
Explanation:
The equilibrium of a weak base as NaCN in water is:
NaCN(aq) + H₂O(l) ⇄ OH⁻(aq) + Na⁺(aq) + HCN(aq)
And kb, the equilibrium constant, is:
Kb = [OH⁻] [HCN] / [NaCN]
Where Kb of NaCN is 2.04x10⁻⁵
In the beginning, the [NaCN] is 0.050mol / L = 0.050M.
Both [OH⁻] and [HCN] are produced from this equilibrium, and its concentration is X, that is:
2.04x10⁻⁵ = [X] [X] / [0.050M]
1.02x10⁻⁶ = X²
X = 1x10⁻³ = [OH⁻]
As pOH = - log [OH⁻]
pOH = 3.00
And pH = 14 - pOH
pH = 11
During the analysis, 0.00905 mol H2O is formed. Calculate the amount (mol) H in 0.00905 mol H2O.
Answer:
0.0181 mol H
Explanation:
Step 1: Given data
Moles of water (H₂O) formed during the analysis: 0.00905 mol H₂O
Step 2: Calculate the amount (mol) H in 0.00905 mol H₂O
According to the chemical formula of water, the molar ratio of water to hydrogen is 1:2, that is, there are 2 moles of H per 1 mole of H₂O. We will use this conversion factor to calculate the moles of H in 0.00905 moles of H₂O.
0.00905 mol H₂O × (2 mol H/1 mol H₂O) = 0.0181 mol H
An analytical chemist weighs out 0.055g of an unknown triprotic acid into a 250mL volumetric flask and dilutes to the mark with distilled water. She then titrates this solution with 0.1300M NaOH solution. When the titration reaches the equivalence point, the chemist finds she has added 6.6mL of NaOH solution. Calculate the molar mass of the unknown acid. Be sure your answer has the correct number of significant digits.
Answer:
Mass of the unknown acid is 4.0g
Explanation:
The determine the molar mass of the unknown acid, the steps below can be followed
Firstly, determine the concentration of the acid, the formula below can be used;
ConcA × Va/ConcB × Vb = Na/Nb
Where ConcA is the concentration of the unknown acid
ConcB is the concentration of the NaOH base
Va is the volume of acid and Vb is the volume of base
Since, the titration was said to have reached an equivalent point, it means the number of moles of the acid (Na) was equal to the number of moles of the base (Nb) and thus both will be assumed to be 1
Thus
ConcA × 250/0.13 × 6.6 = 1/1
ConcA = 0.13 × 6.6/250
ConcA = 0.003432M
Then, determine the actual number of moles (n) of the unknown acid used,
ConcA = no of moles of acid/volume of acid (in dm³ or L)
To convert mL to L, we divide by 1000
Hence, 250ml = 0.25L
0.003432 = n/0.25
n = 0.003432 × 0.25
n = 0.01373 moles
To determine the molar mass;
n = mass/molar mass
The mass was given in the question to be 0.055g
Thus
0.01373 = 0.055/molar mass
molar mass = 0.055/0.01373
molar mass = 4.0g
what is a family in a periodic table?
Answer:
A family is a vertical column .
The elements in a family have similar chemical properties.
Why can we use a water-ethanol mixture but not a water-hexane mixture as a recrystallization solvent? because water and hexane are ___________________.
Answer:
immiscible liquids
Explanation:
When two liquids are to be used for the purpose of recrystallization the both liquids must be miscible with each other in all proportions.
This implies that, if two liquids are immiscible, it will be difficult for the mixture to be useful in recrystallization.
Water and hexane are immiscible because water is a polar solvent and hexane is a non polar solvent.
Water is miscible with ethanol because ethanol contains polar -OH groups that interact effectively with water leading to miscibility of ethanol with water in all proportions.
How many atoms are in one formula unit of the compound FeC5O5?
O 10
05
12
O 11
Answer: D) 11
Explanation:
We have 1 iron atom (the Fe)
We have 5 carbon (denoted [tex]C_5[/tex])
We have 5 oxygen atoms (denoted [tex]O_5[/tex])
So we have 1+5+5 = 11 atoms in this compound.
In one formula unit of [tex]\rm FeC_5O_5[/tex], the number of atoms of oxygen has been 5. Thus , option B is correct.
Formula unit has been the empirical representation of the chemical compound. The formula has been responsible to deliver the information about the number of atoms of each elements present in the sample.
The given compound has been [tex]\rm FeC_5O_5[/tex]. The formula has subscript with each element representing the number of atoms. The atoms of each element has been:
Iron = 1Carbon = 5Oxygen = 5The number of atoms of oxygen present in one formula unit of [tex]\rm FeC_5O_5[/tex] has been 5. Thus , option B is correct.
For more information about the formula unit, refer to the link:
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Which solution, NaCl(aq) or CH3OH(aq), conducts electricity?
Answer:
NaCl(aq)
Explanation:
Nacl(aq) is an electrolyte when it melts and it conducts electricity. This is due to the fact that when it is in solution, it dissociates to be Na+ and Cl-. These ions are conductors of electricity. It conducts electricity because of the movements and also the discharge of ions. CH3OH(aq) is not a conductor of electricity therefore the first option is the answer.
A petroleum refinery is producing the four products shown in the table. The table also shows the state of matter at room temperature of each of the substances. All of these compounds are molecular compounds consisting of only hydrogen and carbon. Which of the following products is likely to have the highest molecular weight? A. Natural gas B. Gasoline C. Jet fuel D. Paraffin wax
Answer:D
Explanation: in molecular solids, one factor that determines the strength of intermolecular forces is the mass of the molecules. Since all of these compounds only contain hydrogen and carbon we don’t have to worry about their polarities as they are all the same. Inter molecular forces tend to be stronger when the molecular weight is greater since paraffin wax is the only solid at room temperature it has the highest melting point
Answer: Your Answer Is D. Paraffin wax
Explanation:Hope This Helps!
The current disintegration rate for carbon-14 is 14.0 Bq. A sample of wood discovered in an archaeological excavation is found to have a carbon-14 decay rate of 0.875 Bq. If the half-life of carbon-14 is 5,700 y, approximately how old is the wood sample?
Answer:
The wood sample has an age of approximately 22800 years.
Explanation:
The Becquerel ([tex]Bq[/tex]) is a SI unit which describes radioactive activity related to decay of radioactive isotopes, which is equivalent to [tex]\frac{1}{s}[/tex]. The decay of radioactive isotope is described by the following ordinary differential equation:
[tex]\frac{dN}{dt} = -\frac{N}{\tau}[/tex] (Eq. 1)
Where:
[tex]\frac{dN}{dt}[/tex] - Disintegration rate, measured in [tex]\frac{1}{s}[/tex].
[tex]N[/tex] - Amount of remaining radioactive nuclei, dimensionless.
[tex]\tau[/tex] - Time constant, measured in seconds.
By integration the solution of this differential equation is obtained:
[tex]\int {\frac{dN}{N} } = -\frac{t}{\tau}\int dt[/tex]
[tex]\ln N = -\frac{t}{\tau} + C[/tex]
[tex]N(t) = N_{o}\cdot e^{-\frac{t}{\tau} }[/tex] (Eq. 2)
Let [tex]N_{1}[/tex] and [tex]N_{2}[/tex] different disintegration rates for Carbon-14 samples, so that:
[tex]N_{1} = N_{o} \cdot e^{-\frac{t_{1}}{\tau} }[/tex] (Eq. 3)
[tex]N_{2} = N_{o}\cdot e^{-\frac{t_{2}}{\tau} }[/tex] (Eq. 4)
If we divide (Eq. 4) by (Eq. 3), then:
[tex]\frac{N_{2}}{N_{1}} = \frac{N_{o}\cdot e^{-\frac{t_{2}}{\tau} }}{N_{o}\cdot e^{-\frac{t_{1}}{\tau} }}[/tex]
[tex]\frac{N_{2}}{N_{1}} = e^{-\frac{1}{\tau}\cdot (t_{2}-t_{1}) }[/tex] (Eq. 5)
If [tex]\Delta t = t_{2}-t_{1}[/tex], we proceed to clear that variable:
[tex]\ln \frac{N_{2}}{N_{1}} = -\frac{1}{\tau}\cdot \Delta t[/tex]
[tex]\Delta t = -\tau\cdot \ln \frac{N_{2}}{N_{1}}[/tex] (Eq. 6)
Time constant is also a function of half-life ([tex]t_{1/2}[/tex]), measured in seconds:
[tex]\tau = \frac{t_{1/2}}{\ln 2}[/tex]
If [tex]t_{1/2} = 1.798\times 10^{11}\,s[/tex], [tex]N_{1} = 14\,\frac{1}{s}[/tex] and [tex]N_{2} = 0.875\,\frac{1}{s}[/tex], the age of the wood sample is:
[tex]\tau = \frac{1.798\times 10^{11}\,s}{\ln 2}[/tex]
[tex]\tau = 2.594\times 10^{11}\,s[/tex]
[tex]\Delta t = -(2.594\times 10^{11}\,s)\cdot \ln \left(\frac{0.875\,\frac{1}{s} }{14\,\frac{1}{s} } \right)[/tex]
[tex]\Delta t \approx 7.192\times 10^{11}\,s[/tex]
[tex]\Delta t \approx 22805.682\,yr[/tex]
The wood sample has an age of approximately 22800 years.
What is cellulose and what does it do?
Answer:
an insoluble substance which is the main constituent of plant cell walls and of vegetable fibers such as cotton. It is a polysaccharide consisting of chains of glucose monomers.
Cellulose is the main substance in the walls of plant cells, helping plants to remain stiff and upright. Humans cannot digest cellulose, but it is important in the diet as fibre. Fibre assists your digestive system – keeping food moving through the gut and pushing waste out of the body.
Explanation:
Answer:
Hello! The main chemical component in cell walls is a complex carbohydrate called cellulose. Cellulose is made of thousands of sugar molecules linked end to end. It is extremely durable, which makes it useful for paper, linen, and cotton products. So the answer to your question is: Cellulose is a very complex carbohydrate that is found in plant walls. In fact, it is the basic structural component in plant walls.
Explanation:
Hope this helped!
How much acceleration does a 10 kg object have if pushed by a 75 N force?
a = 7.5 m/s²
Explanation:Hi there !
Newton's second law
F = m×a => a = F/m
1 N = 1kg·m/s²
a = (75kg.m/s²)/10kg
= 7.5 m/s²
Good luck !
what do elements have to do with geology?
Answer:
Geology is the world... Elements make it up
Explanation:
Answer:
A lot of the elements are found in rocks, minerals, and well since they are elements make they make up everything on earth.
Explanation:
A bicycle rider is applying a force of 20 N while heading south against a wind blowing from the south with a force of 5 N
Answer:
the bike will go down 5 N
Show the net dipole moment (μ = 0 D) of the compounds
a) CBr4
b) cis-1,2-Dibromoethene
c) trans:-1,2-Dibromoethene
d) 1,1-Dibromoethene
Answer:
A
Explanation:
Using the equation above, the dipole moment is calculated to be 1.85 D by multiplying the distance between the oxygen and hydrogen atoms by the charge difference between them and then finding the components of each that point in the direction of the net dipole moment (the angle of the molecule is 104.5˚).
What happen when a piece of sodium is exposed in air?
Answer:
I literally got this from google.
Explanation:
In ordinary air, sodium metal reacts to form a sodium hydroxide film, which can rapidly absorb carbon dioxide from the air, forming sodium bicarbonate. ... In a comparatively dry atmosphere, sodium burns quietly, giving off a dense white caustic smoke, which can cause choking and coughing.
Happy almost Halloween! :)
Which of the following is an example of physical change?
Answer: The glass cup falling
Explanation:
It didnt change chemically, only its physical appearance
Need help with 8 plssss
Answer:
c,a,b,d
Explanation:
PLS HELP WILL DO BRAINLIEST! PLS PLS PLS PLS PLS HELP ASAP Atoms of two different elements must have different
electrical charges.
numbers of neutrons.
atomic numbers.
energy levels.
the answer is atomic numbers
Answer:
atomic numbers
Explanation:
In order for two atoms to be different, they have to have a different number of protons. Protons are represented by the atomic number. Thus, atoms of two DIFFERENT elements must have different atomic numbers.
I took the test and got 100%
Hope this helps!
Having the same number of valence electrons means having similar chemical properties.
True or False
Answer:
True
Explanation:
Because atoms with the same number of valence electrons react in similar ways with other elements.
Consider the reactionI2(g) + Cl2(g)2ICl(g)Using standard thermodynamic data at 298K, calculate the entropy change for the surroundings when 2.41 moles of I2(g) react at standard conditions.S°surroundings = J/K
We know,
[tex]\Delta H_{I_2(g)}=62.438\ KJ/mol\\\\\Delta H_{Cl_2(g)}= 0.0\ KJ/mol\\\\\Delta H_{ICl(g)}=17.78\ KJ/mol[/tex]
For given reaction, [tex]I_2(g)+Cl_2(g)\ -->\ 2ICl(g)[/tex]
[tex]\Delta H_{rxn}=2\Delta H_{ICl(g)}-\Delta H_{I_2(g)}-\Delta H_{Cl_2(g)}\\\\\Delta H_{rxn}=2(17.78)-0-62.438\ KJ/mol\\\\\Delta H_{rxn}=-26.878\ KJ/mol[/tex]
For , 2.41 moles of [tex]I_2[/tex] :
[tex]\Delta H_{rxn}=2.41\times (-26.878)\ KJ\\\\\Delta H_{rxn}=-64.78\ KJ[/tex]
We know :
[tex]\Delta S = -\dfrac{\Delta H_{rxn}}{T}\\\\\Delta S = -\dfrac{-64.78}{298}\ KJ/K\\\\\Delta S =-0.21738 \ KJ/K\\\\\Delta S=-217.38\ J/K[/tex]
Hence, this is the required solution.
The nuclear fission of U-235 can occur by different pathways. If 1 neutron is absorbed by U-235 to produce 36 neutrons and Kr-94, identify other nucleus that is produced using the boxes and pull-down menu provided. g
Answer:
See explanation
Explanation:
What I have written in the image attached is called a nuclear equation. It differs from a chemical reaction equation in the sense that it involves transformations that occur in the nucleus of atoms.
The nuclear equation must be balanced. This means that the mass and charge on both sides of the reaction equation must be the same.
On the left hand side the U-235 interacts with a neutron. The total mass on the left hand side is 236 while the total charge is 92. If we sum up the masses and charges of Ba and Kr, we also get a total of 236 mass units and a charge of 92.
Hence the other nucleus is barium-141
Why doesn't air pressure crush an empty soft-drink can that is sitting on a table in your house?
Answer:
The air inside and outside are equal so air particles can go in and out. The can is empty so the air particles go in and out. That is why the can wont get crushed.
Explanation:
Air pressure does not crush an empty soft-drink can that is sitting on a table in your house as the pressure is equal outside and inside of the can.
What is pressure?Pressure is defined as the force applied on an object perpendicular to it's surface per unit area over which it is distributed.Gauge pressure is a pressure which is related with the ambient pressure.
There are various units by which pressure is expressed most of which are derived units which are obtained from unit of force divided by unit of area . The SI unit of pressure is pascal .
It is a scalar quantity which is related to the vector area element with a normal force acting on it.It is distributed over solid boundaries and across arbitary sections of fluid normal to the boundaries at every point.
Learn more about pressure,here:
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Calculate the number of moles of barium chloride in 427g of a 3.17%by mass barium chloride solution?a) 6.5x10^02molb) 7.83x10^02molc) 4.31x10^02mold) 7.81x10^02mole) 4.27x10^02mol
Answer:
The answer is "Option a".
Explanation:
Multiply the mass of the solutions by 3.17% to get the mass of [tex]BaCl_2[/tex]:
[tex]\to 427 \ g \times 0.0317 = 13.56\ g[/tex]
Divide this mass with BaCl2's molecular concentration to acquire the mole ratio:
[tex]molar mass = 208.24 \frac{g}{mol}\\\\moles = \frac{13.56}{208.24} = 0.065 \ moles \\\\[/tex]
[tex]= 6.5 \times 10^{-2} \ moles[/tex]
A 427 g sample is 3.17% by mass barium chloride contains 6.5 × 10⁻² moles of BaCl₂.
A 427 g sample is 3.17% by mass barium chloride, that is, there are 3.17 g of barium chloride per 100 g of sample.
The mass of barium chloride in 427 g of the sample is:
[tex]427gSample \times \frac{3.17gBaCl_2}{100gSample} = 13.5gBaCl_2[/tex]
We can calculate the number of moles in 13.5 g of barium chloride using its molar mass (208.23 g/mol).
[tex]13.5 g \times \frac{1mol}{208.23g} = 6.5 \times 10^{-2} mol[/tex]
A 427 g sample is 3.17% by mass barium chloride contains 6.5 × 10⁻² moles of BaCl₂.
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Question 5 of 5
Which two phrases describe the nature of an electromagnetic force?
O A. Acts only when objects touch each other
B. Produced by interactions between magnetic objects
O c. Not a fundamental force of nature
O D. Produced by interactions between electrically charged objects
Answer:
I think it's A and D
Explanation:
I'm not sure if it's right
Answer:
The answer is B and D
Explanation:
trust fr
Which of the following best describes the structure of a protein?
a
Carbon ring(s)
b
Hydrocarbon(s)
c
Single or double helix
d
Globular or fibrous
Answer:
I'm pretty sure its d.
Explanation:
because a gbular protein is a protein that is round in shape, and a fibrous is a long a thin shaped protein. Which those are two kinds of proteins.
Bromine is found above iodine in Group 17 of the periodic table. If an ion formed by bromine has a charge of 1-, what is the charge on an ion
formed by iodine?
A. -7
B. -2
C. -1
D. +1
Answer:
Explanation:
Iodine is the most flexible of the atoms in Group 17 of the periodic table. It can have more than 1 charge, especially when combined with oxygen. The answer that you are expected to give, I think is C. Iodine's dominant charge is - 1
