Please select the word from the list that best fits the definition
Include skin, the respiratory system, the circulatory system, and inflammation
A. antibody
B. antigen
C.Natural Defences
D.active immunity
Answer:
I choose D option because may be it's correct
I believe it is c
Explanation:
because if u think about it and also do some research you would see that the circulatory system is a strong part of your body which can help u through natural defences if this sounds weird it's all in research but if it ain't c dont blame me for ruining your life- lol but yeah I think its c
C8H18+O2=CO2+H2O. Balance this equation and identify the number H2O molecules formed when 6 molecules of C8H18 react with 75 molecules of oxygen
Answer: 54 molecules of water will be formed in the reaction.
Explanation:
A balanced chemical equation is one where all the individual atoms are equal on both sides of the reaction. It follows the law of conservation of mass.
For the given unbalanced chemical equation, the balanced equation follows:
[tex]2C_8H_{18}+25O_2\rightarrow 16CO_2+18H_2O[/tex]
We are given:
Molecules of [tex]C_8H_{18}[/tex] = 6
Molecules of [tex]O_2[/tex] = 75
By the stoichiometry of the reaction:
If 2 molecules of [tex]C_8H_{18}[/tex] produces 18 molecules of water
So, 6 molecules of [tex]C_8H_{18}[/tex] will produce = [tex]\frac{18}{2}\times 6=54[/tex] molecules of water
Hence, 54 molecules of water will be formed in the reaction.
Suppose that you add 29.2 g of an unknown molecular compound to 0.250 kg of benzene, which has a K f of 5.12 oC/m. With the added solute, you find that there is a freezing point depression of 2.78 oC compared to pure benzene. What is the molar mass (in g/mol) of the unknown compound
Answer:
Suppose that you add 29.2 g of an unknown molecular compound to 0.250 kg of benzene, which has a K f of 5.12 oC/m. With the added solute, you find that there is a freezing point depression of 2.78 oC compared to pure benzene. What is the molar mass (in g/mol) of the unknown compound
Explanation:
The mass of nonvolatile solute added is ---- 29.2g
The mass of solvent benzene is ---- 0.250kg = 250g
The Kf value of benzene is ---- 5.12^oC/m.
Depression in the freezing point of the solution is --- 2.78^oC.
What is the molar mass of the unknown solute?
[tex]The depression in freezing point = Kf * molality of the solution\\molality of the solution = \frac{mass of solute}{molar mass of solute}*\frac{1}{mass of solvent in kg}[/tex]
Substitute the given values in this formula to get the molar mass of unknown solvent:
[tex]molality=\frac{29.2g}{M} * \frac{1}{0.250kg} \\depression in freezing point:\\2.78^oC=5.12^oC/m * \frac{29.2g}{M} * \frac{1}{0.250kg} \\\\=>M=5.12^oC/m * \frac{29.2g}{2.78^oC} * \frac{1}{0.250g} \\\\\\=>M=215.1g/mol[/tex]
Hence, the molar mass of unknown solute is --- 215g/mol.
19. What is the molarity of a
solution that contains 6 liters
of solution and 2 moles of
solute?
a. 8 M
b. 0.3 mol/L
c. 12 mol/L
d. 3M
Answer:
b. 0.3 mol/L is the closest.
Explanation:
A molar solution of a substance contains 1 mole per liter of solution
So if we have 2 moles in 6 liters the there are 2/6 =1/3 of a mole in 1 liter.
What is the name of the functional group that is attached to this hydrocarbon?
H
H
alkyl halide
alcohol
carbonyl
ketone
Answer:
ketone
Explanation:
Write the molecular formula for the compound that exhibits a molecular ion at M+ = 112.0499. Assume that C, H, N, and O might be present, and use the exact masses below:
Exact mass of carbon = 12.000
Exact mass of hydrogen = 1.0078
Exact mass of nitrogen = 14.003
Exact mass of oxygen = 15.995
The order of atoms should be carbon, then hydrogen, then the others in alphabetical order.
Answer:
C₆H₁₀NO
Explanation:
In order to arrive at a molecular formula we have to make some assumptions and they are
Assuming there is one ( 1 ) N and one ( 1 ) O that is present in the said molecule
Total mass = 29.998
next step: subtract the total mass from 112.0499 = 82.501
next : assume the presence of 6 carbon atoms in said molecule
Total mass = 6 * 12 = 72
Mass of Hydrogens = 82.501 - 72 = 10.501
∴ number of hydrogens = 10.501 / 1.0078 ≈ 10
Hence Total mass = 29.998 + 82.501 ≈ 112.0499
Finally Molecular formula = C₆H₁₀NO
How does the law of conservation of mass relate to the number of atoms of each element that are present before a reaction vs. the number of atoms of each element that are present after a chemical reaction?
A rod “X”, has a positive charge of 5. An otherwise identical rod, “Y”, has a negative charge of 12.
The rods are touched together and then separated.
a) When they touched, what particles moved between them?
b) Did the particles move from “X” to “Y” or from “Y” to “X”.
Answer:
a) electrons
b) from Y to X
Explanation:
positive protons are the cores of atoms in relative to electrons very, very heavy.
the outer electrons of atoms can move, under certain conditions, away from the atom, leaving it electrically unbalanced -> positively charged
there can also be a surplus of electrons on many surfaces, leading to a static negative charge. you know this when you are charged and you discharge with an object or another person, electrically balancing the two bodies charge.
electrons are also much smaller. they are the "things" to move, let it be trough the air or trough a wire, while the heavy protons will stay in place (unless the materials is melted of course, extreme heat brakes the bounds between atoms relatively well)
Hydrogen bonds within liquid water are attractions between protons and hydroxide ions. are dipole-dipole attractions. are ion-induced dipole attractions. are attractions between protons and oxygen nuclei. are attractions between two hydrogen atoms.
Answer:
true because the bonds cannot be broken down
Name the following ketone:
A sample of carbon tetrachloride (CCl4) contains 3 moles of the substance. How many atoms are there in the sample?
Answer:
1.806 × 10²⁴ atoms
Explanation:
To obtain the number of atoms a substance contain, we have to multiply the number of moles in that substance (n) by Avogadro's number, which is 6.02 × 10²³.
According to this question, a sample of carbon tetrachloride (CCl4) contains 3 moles of the substance. The number of atoms in CCl4 is calculated thus:
number of atoms = 3 × 6.02 × 10²³
number of atoms = 18.06 × 10²³
number of atoms = 1.806 × 10²⁴ atoms.
A buffer solution contains 0.475 M nitrous acid and 0.302 M sodium nitrite . If 0.0224 moles of potassium hydroxide are added to 150 mL of this buffer, what is the pH of the resulting solution
Answer: The pH of the resulting solution will be 3.001
Explanation:
Molarity is calculated by using the equation:
[tex]\text{Molarity}=\frac{\text{Moles}}{\text{Volume}}[/tex] ......(1)
We are given:
Moles of NaOH = 0.0224 moles
Molarity of nitrous acid = 0.475 M
Molarity of sodium nitrite = 0.302 M
Volume of solution = 150 mL = 0.150 L (Conversion factor: 1 L = 1000 mL)
Putting values in equation 1, we get:
[tex]\text{Moles of nitrous acid}=(0.475mol/L\times 0.150L)=0.07125mol[/tex]
[tex]\text{Moles of sodium nitrite}=(0.302mol/L\times 0.150L)=0.0453mol[/tex]
The chemical equation for the reaction of nitrous acid and NaOH follows:
[tex]HNO_2+NaOH\rightleftharpoons NaNO_2+H_2O[/tex]
I: 0.07125 0.0224 0.0453
C: -0.0224 -0.0224 +0.0224
E: 0.04885 - 0.0677
The power of the acid dissociation constant is the negative logarithm of the acid dissociation constant. The equation used is:
[tex]pK_a=-\log K_a[/tex] ......(2)
We know:
[tex]K_a[/tex] for nitrous acid = [tex]7.2\times 10^{-4}[/tex]
Using equation 2:
[tex]pK_a=-\log (7.2\times 10^{-4})=3.143[/tex]
To calculate the pH of the acidic buffer, the equation for Henderson-Hasselbalch is used:
[tex]pH=pK_a+ \log \frac{\text{[conjugate base]}}{\text{[acid]}}[/tex] .......(3)
Given values:
[tex][NaNO_2]=\frac{0.0677}{0.150}[/tex]
[tex][HNO_2]=\frac{0.04885}{0.150}[/tex]
[tex]pK_a=3.143[/tex]
Putting values in equation 3. we get:
[tex]pH=3.143-\log \frac{(0.0677/0.150)}{(0.04885/0.150)}\\\\pH=3.143-0.142\\\\pH=3.001[/tex]
Hence, the pH of the resulting solution will be 3.001
The information code that an organism inherits can best be referred to as its -
O A genotype
B. territory
C. species
D. kingdom
Answer:
it will be no.A genotype
An elementary step is defined as a chemical collision in a reaction mechanism. A collection of different types of collisions makes up the reaction mechanism, so elementary steps provide a molecular view of the overall reaction.
a. True
b. False
Consider the following equilibrium:
HC2O4- + HSO4- <—> H2C2O4 + SO42-
The order of Bronsted-Lowry acids and bases in the reaction is_________ .
Answer:
See explanation
Explanation:
According to Bronsted-Lowry definition of acids/bases, an acid is a proton donor while a base is a proton acceptor.
Hence, in a reaction, the species that donate protons are strong acids while the species that accept protons are strong bases.
Hence, HSO4- is a stronger acid than H2C2O4 and SO42- is a weaker base than HC2O4-
Note that the conjugate base of a strong acid is a weak base and vice versa.
To make a 0.500 M solution, one could take 0.500 moles of solute and add Group of answer choices enough solvent to make 1.00 kg of solution. enough solvent to make 1.00 L of solution. 1.00 L of solvent. 1.00 kg of solvent.
Answer: The correct option is enough solvent to make 1.00 L of solution
Explanation:
A solution consists of solute and solvent. A solute is defined as the component present in a smaller proportion while the solvent is defined as the component that is present in a larger proportion.
Molarity is defined as the amount of solute expressed in the number of moles present per liter of solution. The units of molarity are mol/L. The formula used to calculate molarity:
[tex]Molarity=\frac{Moles}{Volume}[/tex] .......(1)
We are given:
Molarity of solution = 0.500 M
Moles of solute = 0.500 moles
Putting values in equation 1, we get:
[tex]0.500mol/L=\frac{0.500mol}{\text{Volume of solution}}\\\\\text{Volume of solution}=\frac{0.500mol}{0.500mol/L}=1.00L[/tex]
Hence, the correct option is enough solvent to make 1.00 L of solution
PLEASE HELP‼️‼️
A
B
C
D
Which type of scientist would most likely investigate how to synthesize
materials found in plants?
O A. A geologist
O B. A biologist
O C. A chemist
OD. A physicist
Answer:
Biologist
Explanation:
Not sure, but I think that is right
What is the limiting reactant for the following reaction given we have 2.6 moles of HCI and 1.4 moles of
Ca(OH)2?
Reaction: 2HCI + Ca(OH)2 → 2H2O + CaCl2
Determine the electron geometry, molecular geometry, and idealized bond angles for each of the following molecules. CF4CF4 NF3NF3 OF2OF2 H2SH2S In which cases do you expect deviations from the idealized bond angle
Answer:
CF4
Molecular geometry- tetrahedral
Electron geometry- tetrahedral
NF3
-molecular geometry - trigonal pyramidal
Electron geometry - tetrahedral
OF2
Molecular geometry - bent
Molecular geometry - tetrahedral
H2S
Molecular geometry- bent
Electron geometry - tetrahedral
Explanation:
According to Valence Shell Electron Pair Repulsion Theory, the shape of a molecule depends on the number of electron pairs on the valence shell of the central atom in the molecule.
For all the compounds listed, the central atom has four points of electron density. This correspond to a tetrahedra electron pair geometry. The presence of lone pairs on the central atom of OF2,NF3 and H2S accounts for the departure of the observed molecular geometry from the geometry and idealized bond angle predicted on the basis of the VSEPR theory.
Boric acid, B(OH)3, acts as an acid in water, but does not do so via ionization of a proton from boric acid. Use a balanced chemical equation to show why boric acid may be described as an acid in water.
Answer:
B(OH)₃ + H₂O = B(OH)₄⁻ + H⁺
Explanation:
Let's consider Arrhenius acid-base theory:
An acid is a substance that in aqueous media releases H⁺.A base is a substance that in aqueous media releases OH⁻.Boric acid, B(OH)₃ reacts with water according to the following equation.
B(OH)₃ + H₂O = B(OH)₄⁻ + H⁺
As we can see, boric acid releases H⁺ in aqueous media. Thus, it is an acid.
What happens when you increase the pressure on the following
reaction
2X(g) + 3Y(g) --> 5Z(g) + heat
Answer:
When pressure increases, there is no effect on the reaction because volume is constant.
Discuss the any two applications of Beer’s law with suitable justification.
Answer: It's used in chemistry to measure the concentration of chemical solutions.
Explanation:
Beer's Law is used in chemistry to measure the concentration of chemical solutions, to analyze oxidation, and to measure polymer degradation.
The law also describes the attenuation of radiation through the Earth's atmosphere
gress.
Newton's third law of motion
Is the following statement true or false?
When a large truck pushes a small car with a given force, the small car is applying an equal and opposite
force on the truck.
Choose 1 answer:
True
False
Answer:
true
Explanation:
the small car also has gravity making it heavy
3. Which of the following can be physically separated?
Answer:
mixture
Explanation:
an example of one is a salad you can separate the ingredients
A 250ml sample of sir at 373.15k is warmed at 473.15 at constant pressure. What is the volume of the air sample at the new temperature
Answer:
317 mL.
Explanation:
From the question given above, the following data were obtained:
Initial volume (V₁) = 250 mL
Initial temperature (T₁) = 373.15 K
Final temperature (T₂) = 473.15 K
Pressure = Constant
Final volume (V₂) =?
The final volume of the air sample can be obtained by using the Charles' law equation as illustrated below:
V₁/T₁ = V₂/T₂
250 / 373.15 = V₂ / 473.15
Cross multiply
373.15 × V₂ = 250 × 473.15
373.15 × V₂ = 118287.5
Divide both side by 373.15
V₂ = 118287.5 / 373.15
V₂ = 317 mL
Therefore, the final volume of the air sample is 317 mL
5
The
(1 Point)
can change when describing motion. It is just the chosen starting point.
displacement
distance
reference point
speed
Elements beyond iron are not formed by a-particle capture. It is believed they are formed by neutron capture. Once the nucleus gets enough neutrons, one neutron converts to an electron and a proton. Show how you can make zinc from copper by neutron capture.
Answer: The equation is [tex]_{29}^{63}\textrm{Cu}\rightarrow _{30}^{63}\textrm{Zn}+_{-1}^0e[/tex]
Explanation:
Neutron capture is a process where a neutron is converted into a proton and an electron. The released particle is known as beta particle and it carries a charge of -1 units and has a mass of 0 units. It is also known as an electron. The general equation for this process is:
[tex]_Z^A\textrm{X}\rightarrow _{Z+1}^A\textrm{Y}+ _{-1}^0\e[/tex]
The nuclear equation for the formation of zinc via neutron capture of copper follows:
[tex]_{29}^{63}\textrm{Cu}\rightarrow _{30}^{63}\textrm{Zn}+_{-1}^0e[/tex]
The volume of a gas is 200.0 mL and the pressure is 2.00 atm. When the volume of the gas is 10 mL what is the pressure if the temperature remains the same?
Answer:
40 atm
Explanation:
Boyles law states that the pressure exerted on a gas is inversely proportional to the volume it occupies provided that the temperature is held constant. It is given by:
P ∝ 1/V
PV = constant
P₁V₁ = P₂V₂
Given that V₁ = initial volume = 200 ml, P₁ = initial pressure = 2 atm, V₂ = final volume = 10 ml, P₂ = final pressure. Hence:
2 atm * 200 ml = P₂ * 10 ml
P₂ = (2 atm * 200 ml) / 10 ml
P₂ = 40 atm
Compound A has the formula C8H8. It reacts rapidly with acidic KMnO4 but reacts with only 1 equivalent of H2 over a palladium catalyst. On hydrogenation under conditions that reduce aromatic rings, A reacts with 4 equivalents of H2, and hydrocarbon B, C8H16, is produced. The reaction of A with KMnO4 gives CO2 and a carboxylic acid C, C7H6O2.
Required:
Draw the structure of compound B below.
Answer:
C8H16 (Ethylcyclohexane).
Explanation:
From the given information:
Compound A is an alkene because it interacts with 1 unit of hydrogen across a palladium catalyst.
Also, we are given another hint that:
Compound A needs 4 equivalence of H2 to hydrogenate under circumstances that decrease aromatic rings, indicating that it is a phenyl substituted alkene.
Compound A with formula C8H8 reacts instantly with KMnO4 to produce CO2, as well as carboxylic acid, points out that Compound acts as a terminal alkene.
Therefore, we can opine that compound A is a terminal phenyl substituted alkene whose formula = C8H8 (Styrene)
The diagrammatic expression of the compound can be seen below.
However, in the presence of the palladium catalyst, the reduction of Compound A with 4 units of hydrogen produces Compound B: C8H16 (Ethylcyclohexane).
