Answer:
The main function of the immune system is to provide immunity to the body. Immunity is the body's ability to protect itself from the pathogens it is exposed to. Immunity depends on the body's ability to differentiate between things that belong in the body and those that do not. The immune system's first line of defense includes physical and chemical barriers that are always ready and prepared to defend the body from infection.
The skin acts as a barrier against pathogens. Some structures of the first line of defense include the skin, mouth, eyes, ears, nose, and stomach. The skin produces sweat and oil that work together to keep pathogens from the entering the body. Saliva and tears contain substances the can destroy pathogens. The ears and the stomach help fight pathogens.The ears produce ear wax that prevent pathogens from entering the ears. The stomach produces a liquid the kills pathogens.
Mucus is produce by the nose, lungs, throat, and stomach. Mucus traps pathogens. Mucus also prevent pathogens from getting into deep tissues. Anyway, the very first line of defense against any invasion of the human body is a set of physical barriers between the inside of the body and the outer world.
*my notes from edge2020*
Hope this helps ^-^
How does one determine a percent composition from an empirical
formula?
A. Divide the atomic mass of the element by its subscript and
multiply by 100%
O B. Divide the mass of the compound by the atomic mass of
the element and multiply by 100%
O C. Divide the subscript of the element by the mass of the
element and multiply by 100%
O D. Divide the total mass of each element by the mass of the
compound and multiply by 100%
The way one determines a percent composition from an empirical formula is to divide the total mass of each element by the mass of the compound and multiply by 100%.
What is empirical formula?Empirical formula is a notation that indicates the ratios of the various elements present in a compound, without regard to the actual numbers.
The empirical formula of a compound is the simplest ratio that can exist between the constituent elements of a compound.
However, the percent composition of a compound can be determined by dividing the total mass of each element by the mass of the compound and multiply by 100%.
Learn more about empirical formula at: https://brainly.com/question/14044066
#SPJ2
what is the iupac name of CH3-CH2CH(CH3)CH2-COOH
Answer:
Butanoic acid.
Explanation:
What is the mass of the oxygen in one mole of calcium phosphate
Answer:
16.00 g/mol
Explanation:
Answer:
16.00 g/mol
Explination:
1 mol of calcium phosphate contains 8 moles of oxygen. From this, we can compute for the amount of oxygen in grams using the molar mass of oxygen, which is 16.00 g/mol.
Compare and contrast the applications and benefits of circle graphs and bar charts. Explain
Answer:
A circle graph, or a pie chart, is used to visualize information and data. A circle graph is usually used to easily show the results of an investigation in a proportional manner. Bar graphs are used to compare things between different groups or to track changes over time. However, when trying to measure change over time, bar graphs are best when the changes are larger.
Explanation:
In short, bar graphs are better to keep track of data over long periods of time, and circle graphs are better when you are trying to visualize a specific set of data.
Circle graph can be also be called pie chart, which is more widely used. It is usually made up of a circle, divided into parts or pies. In the divided parts, it is used to differentiate between different data.
Bar charts on the other hand are like graphs having both x and y axis. It is used to represent data with respect to the height of the graph. Each data is divided into different smaller parts on the graph.
Example of what they look like is attached below.
First one is bar chart while the second is a circle graph
for more on this, visit: https://brainly.com/question/3661259
what ore is turned to finished aluminum
The reaction between iron(II) oxide and carbon monoxide produces iron and carbon dioxide. How many moles of iron can be obtained when 1.50 mol FeO reacts with an excess of CO ?
FeO+CO⟶Fe+CO2
Answer:
1.5 moles of Fe produced.
Explanation:
Given data:
Moles of FeO react = 1.50 mol
Moles of iron produced = ?
Solution:
Chemical equation:
FeO + CO → Fe + CO₂
Now we will compare the moles of ironoxide with iron.
FeO : Fe
1 : 1
1.5 : 1.5
Thus from 1.5 moles of FeO 1.5 moles of Fe are produced.
1.5 moles of Fe can be obtained when 1.50 mol of FeO reacts with an excess
of CO
Moles of FeO reacted = 1.50 mol
Moles of iron produced = ? mol
The chemical equation is given as
FeO + CO → Fe + CO₂
Comparisons of FeO and Fe show they are in the ratio 1 : 1
FeO : Fe
1.5 : 1.5
which translates to the number of moles being equal
Therefore, 1.5 moles of FeO 1.5 moles of Fe are produced.
Read more on https://brainly.com/question/19123159
Name something that has zero thermal energy.
Answer:
When all molecules in a system stop moving completely, there is zero thermal energy
Explanation:
It is impossible to reach though
Arrange the following compounds in order of increasing acidity, and explain the reasons for your choice of order. Enter your answer in the answer box below. a. 4-nitrophenol b. cyclohexanol c. 2,6-difluorocyclohexanol d. 4-bromophenol
Answer:
(a) > (d) > (c) > (b)
Explanation:
Acidic character is based upon inductive effect of the functional group that are attached to parent chain.
1. Nitro is a -I group which makes phenol acidic due to increased resonance, 2. bromine is a -I group but it is weaker than nitro group
3. phenol is more acidic than cyclohexanol due to resonance stabilization of resonance and among halogen F>Cl>Br>I is the order of acidity
4. cyclohexanol will be weakest as it is not associated with any -I groups here.
so the order of acidity will be
(a). 4-nitropheno > (d). 4-bromophenol > (c). 2,6-difluorocyclohexanol > (b). cyclohexanol
Is iron man made or natural
Answer:
Iron is natural. Paper is man-made
Explanation:
Answer:
iron
Explanation:
7.46 - A 0.0500-mol sample of a nutrient substance is burned in a bomb calorimeter containing 2.00 x 10g H20. If the formula weight of this nutrient substance is 114 g/mol, what is the fuel value (in nutritional Cal) if the temperature of the water increased 5.70C?
Answer:
[tex]200\frac{kcal}{g}[/tex]
Explanation:
Hello!
In this case, for this calorimetry problem, since the combustion 0.0500 mol of the nutrient increase the temperature of water by 5.70 °C, we can notice that the heat lost by the nutrient is gained by water in order to write:
[tex]Q_{nutrient}=-Q_{water}[/tex]
Which can be also written as:
[tex]Q_{nutrient}=-m_{water}C_{water}\Delta T_{water}\\\\Q_{nutrient}=-200 g*4.184\frac{J}{g\°C}*5.70\°C\\\\Q_{nutrient}=4769.8 J[/tex]
Thus, in terms of the grams of the nutrient:
[tex]m_{nutrient}=0.0500mol*\frac{114g}{1mol}=5.70g[/tex]
The fuel value in nutritional Cal (kcal/g) turns out:
[tex]Fuel \ Value=\frac{-4.7698kJ}{5.70g}*\frac{1kcal}{4.184kJ}=200\frac{kcal}{g}[/tex]
Best regards!
If 15.5 mL of 0.225 M aqueous magnesium chloride is added to 37.5 mL of 0.250 M aqueous lead(II) nitrate, then what mass of lead(II) chloride precipitates?A. 0.485 g.B. 0.971 g.C. 1.94 g.D. 3.888 g.E. 5.82 8 g.
Answer:
B. 0.971 g
Explanation:
When MgCl₂(aq) reacts with Pb(NO₃)₂(aq), PbCl₂(s) and Mg(NO₃)₂(aq) are produced:
MgCl₂(aq) + Pb(NO₃)₂(aq) →, PbCl₂(s) + Mg(NO₃)₂(aq)
Thus, we need to find imiting reactant finding moles of each reactant:
Moles MgCl₂:
15.5mL = 0.0155L * (0.225 mol / L) = 3.49x10⁻³ moles
Moles Pb(NO₃)₂:
37.5mL = 0.0375L * (0.250mol / L) = 9.38x10⁻³ moles
As the ratio of the reactants is 1:1, the moles of PbCl₂ are 3.48x10⁻³ moles.
We need to convert thes moles to mass using molar mass of PbCl₂ (278.1g/mol), thus:
3.48x10⁻³ moles * (278.1g/mol) =
0.968g of PbCl₂ are precipitate
Thus, right answer is:
B. 0.971 gIdentify the necessary parts to build a calorimeter. Select one or more:________ A. Cover. B. An interior paper cup. C. Thermometer. D. An interior styrofoam cup. E. An exterior paper cup An exterior styrofoam cup Conductivity probe.
Answer:
Explanation:
A calorimeter is an instrument used for measuring the heat of reactions and heat capacity. A calorimeter should contain an insulating cover, a thermometer, styrofoam cups (you could have that both on the inside and the outside in the case of a styrofoam calorimeter) and you could also have a conductivity probe (in the form of ignition wires and bulb).
A calorimeter is the analytical device used to measure the heat of the reaction. The construction of calorimeter requires cover, paper cup, thermometer, styrofoam cup, and conductivity probe.
How to build a calorimeter?In a chemical reaction, the amount of heat released or absorbed by the reaction helps in the analysis of various parameters. The calorimeter measures the heat of the reaction.
The construction of a calorimeter requires:
Paper can for the filling of water.Cover to stop the loss of heatStyrofoam cup to allow the reactionThermometer to measure the change in temperatureConductivity probe to allow the transfer of heat energyLearn more about calorimeter, here:
https://brainly.com/question/14989357
If you had to choose,
Happiness or Power? (Any type of Power)
Answer:
I will choose Happiness, Happiness, Happiness, Happiness.....
☺️❤️
Explanation:
Why Happiness Matters
It's the feeling of truly enjoying your life, and the desire to make the very best of it. Happiness is the "secret sauce" that can help us be and do our best. Here's what researchers found when they studied happy people: Happy people are more successful.
Scientific evidence suggests that being happy may have major benefits for your health. For starters, being happy promotes a healthy lifestyle. It may also help combat stress, boost your immune system, protect your heart and reduce pain. What's more, it may even increase your life expectancy.
Examples of solutions can be:
O A. a solid dissolved in a liquid
O B. gas mixed with a liquid
O C. liquid mixed with a liquid
OD. all of the the above
Answer:
B. gas mixed with a liquid
Explanation:
because:
A. a solid can't dissolve in a liquid.
C. two liquids mixed isn't a solution
D. Not All of the above for sure.
Examples of solutions can be all of the above. The correct option is D.
What is a solution?A solution is made when a solute is mixed with a solvent. The solution can be a liquid, solid, or gas. The solution is made when the solute is fully mixed with the solvent. The solute is the substance that gets mixed, and the solvent is the base in which the solute gets dissolved.
So, a solid dissolved in a liquid, gas mixed with a liquid, or a liquid mixed with a liquid, the energy statement is true for a solution.
Examples of a solution are sugar dissolved in water when water mix with soda and state gets mixed with water or another gas.
Thus, the correct options are D. all of the the above.
Learn more about the solution, here:
https://brainly.com/question/1416865
#SPJ2
If 0.0806 mol CaCl2 is dissolved in water to make a 0.490 M solution, what is the volume of the solution?
Answer:
0.16 L
Explanation:
From the question given above, the following data were obtained:
Mole = 0.0806 mole
Molarity = 0.490 M
Volume =?
Molarity is simply defined as the mole of solute per unit litre of the solution. Mathematically, it is expressed as:
Molarity = mole /Volume
With the above formula, we can obtain the volume of the solution as illustrated below:
Mole = 0.0806 mole
Molarity = 0.490 M
Volume =?
Molarity = mole /Volume
0.490 = 0.0806/volume
Cross multiply
0.490 × volume = 0.0806
Divide both side by 0.490
Volume = 0.0806 / 0.490
Volume of solution = 0.16 L
Thus, the volume of the solution is 0.16 L.
A solution is a mixture of solute in the solvent. The volume of the solution is 0.16 L.
What is a solution?A solution is a mixture of solute in the solvent.
An example of a solution is a mixture of salt in water.
Given,
Moles = 0.0806 mol [tex]\rm CaCl_2[/tex]
Molarity = 0.490 M
To find: the volume of the solution
[tex]Molarity = \dfrac{n}{V}[/tex]
Putting the values
[tex]0.490 M = \dfrac{ 0.0806}{V}\\\\0.490 M \times V = 0.0806\\\\Divide\; both\;side\; with\; 0.490\\\\V= \dfrac{ 0.0806}{0.490}=0.16 L[/tex]
Thus, the volume so the solution is 0.16 l.
Learn more about the solution, here:
https://brainly.com/question/7932885
A Beer's Law Plot of sample A gives a slope equal to 1.2 M-1cm-1. Calculate molar concentration of this sample at a wavelength of 420 nm and an absorbance reading of 0.23 in a 1 cm cuvette.
Answer:
[tex]0.192\ \text{M}[/tex]
Explanation:
A = Absorbance of solution
E = Molar absorptivity
l = Length of cuvette = 1 cm
c = Concentration of solution
Beer's law is given by
[tex]A=Elc[/tex]
The equation of a straight line is given by
[tex]y=mx+c[/tex]
Comparing the above equations we get
Value on [tex]y[/tex] axis = A = Absorbance of solution = 0.23
[tex]m[/tex] = Slope of line = El = Molar absorptivity multiplied with length = [tex]1.2\times 1\ \text{M}^{-1}[/tex]
[tex]x[/tex] = Value of x axis = c = Concentration of solution
So we get
[tex]c=\dfrac{A}{El}\\\Rightarrow c=\dfrac{0.23}{1.2\times 1}\\\Rightarrow c=0.192\ \text{M}[/tex]
The molar concentration of the sample is [tex]0.192\ \text{M}[/tex]
branches of sicence
Answer:
Natural science can be divided into two main branches
Explanation:
life science and physical science. Life science is alternatively known as biology, and physical science is subdivided into branches: physics, chemistry, astronomy and Earth science.
Answer:
Astronomy
Biology
Geology
Chemistry
Please Mark Brainliest and rate me 5
Thank You Good Night / Good Day to you
explain what happens to temperature and energy as molecules move from gas to liquid to solid
Answer and Explanation:
As the temperature of the substances increases, the average energy of the molecules increases, and average energy of attraction between the molecules decreases consequently intermolecular spacing between the molecules increases. As a result, a substance change in succession from gas to liquid to solid.
I NEED HELP ASAP PLEASE I BEG
with what?..................
given that the only known ionic charges of lead are pb(ii) and pb(iv), how can you explain the existence of the pb2o3 salt
Answer:
See Explanation
Explanation:
Pb2O3 is better formulated as PbO.PbO2. It is actually a mixture of the two oxides of lead, lead II oxide and lead IV oxide.
This implies that this compound Pb2O3 (sometimes called lead sesquioxide) is a mixture of the oxides of lead in its two known oxidation states +II and +IV.
Hence Pb2O3 contains PbO and PbO2 units.
For the following reaction at equilibrium SO3(g) + NO(g) = SO2(g) + NO2(g)It is found that [SO2] = 0.70 M and [NO] = 1.20 M. Calculate the equilibrium constant for the readction knowing that the initial concentration were [SO3] = 2.55 M and [NO] = 1.90 M.
Answer:
[tex]K=0.14[/tex]
Explanation:
Hello!
In this case, for the undergoing chemical reaction, we can write the equilibrium expression via:
[tex]K=\frac{[SO_2][NO_2]}{[SO_3][NO]}[/tex]
Whereas the equilibrium concentration of both SO3 and NO are 2.55 M and 1.90 M respectively, it means that the extent of reaction [tex]x[/tex] is:
[tex]x=1.90M-1.20M=0.7M[/tex]
Because the equilibrium expression in terms of the reaction extent is:
[tex]K=\frac{x*x}{([SO_3]_0-x)([NO]_0-x)}[/tex]
It means that the concentration of SO3, NO, SO2 and NO2 at equilibrium are:
[tex][SO_3]=2.55M-0.70M=1.85M[/tex]
[tex][NO]=1.20M[/tex]
[tex][SO_2]=0.70M[/tex]
[tex][NO_2]=0.70M[/tex]
Thus, the equilibrium constant for such reaction is:
[tex]K=\frac{0.70*0.70}{1.85*1.90}\\\\K=0.14[/tex]
Best regards!
In ethane, C2H6, ethene (ethylene), C2H4, and ethine (acetylene), C2H2, there are direct carbon-carbon bonds. Which one is the shortest?
a. The carbon-carbon bond in ethane's the longest!)
b. The carbon-carbon bond in ethene is the longest
c. The carbon-carbon bond in ethyne is the longest.
d. All of the carbon-carbon bonds have the same length.
Answer:
a. The carbon-carbon bond in ethane's the longest!)
Explanation:
Ethane is a chemical compound that is organic in nature. Its chemical formula is [tex]$C_2H_6$[/tex]. It has two carbon atoms and six of hydrogen atoms that is connected to the carbon atoms.
Ethane is odorless and colorless at the standard temperature and standard pressure.
The carbon to carbon atoms in ethane is connected by a single bond.
The length of single carbon-carbon bond is greater than carbon-carbon double bond and triple bond.
Thus, carbon-carbon bond length in ethane is the longest.
What is the hybridization state on the central N atom in the azide ion, N3−?
Which of the following has a nonpolar bond? *
02
HCI
NH3
CH4
Answer: CH4
Explanation:
BRAINLESS PLEASE
Answer:
O₂
Explanation:
The example of the compound or the molecule that forms a non-polar bond is oxygen gas.
Oxygen gas has a formula of O₂
Since this is a homonuclear molecule, the two bonding atoms have the same kind of electronegativity. The difference is therefore zero. In such a molecule, there is equal sharing of the electron pair between the atoms and no electrostatic charge on the molecule.The molarity (M) of an aqueous solution containing 22.5 g of sucrose (C12H22O11) in 35.5 mL of solution is ________.
Answer:
1.86 M
Explanation:
From the question given above, the following data were obtained:
Mass of sucrose (C12H22O11) = 22.5 g
Volume of solution = 35.5 mL
Molarity of solution =?
Next, we shall determine the number of mole in 22.5 g of sucrose (C12H22O11). This can be obtained as follow:
Mass of sucrose (C12H22O11) = 22.5 g
Molar mass of C12H22O11 = (12×12) + (22×1) + (16×11)
= 144 + 22 + 176
= 342 g/mol
Mole of C12H22O11 =?
Mole = mass /Molar mass
Mole of C12H22O11 = 22.5 /342
Mole of sucrose (C12H22O11) = 0.066 mole
Next, we shall convert 35.5 mL to litres (L). This can be obtained as follow:
1000 mL = 1 L
Therefore,
35.5 mL = 35.5 mL × 1 L / 1000 mL
35.5 mL = 0.0355 L
Thus, 35.5 mL is equivalent to 0.0355 L.
Finally, we shall determine the molarity of the solution as follow:
Mole of sucrose (C12H22O11) = 0.066 mole
Volume of solution = 0.0355 L.
Molarity of solution =?
Molarity = mole /Volume
Molarity of solution = 0.066/0.0355
Molarity of solution = 1.86 M
Therefore, the molarity of the solution is 1.86 M.
PLZ HELP TAKING TEST NOW. WILL GIVE BRAINLIEST
Some students decided to do an experiment with a can of pop. They opened the 340 g can of pop and left it open for a day. They then measured the pop can and found it was 332 g. Does this break the law of conservation of mass? Explain why or why not.
What two options are homogeneous mixture
Answer:
vinegar and soap
Explanation:
Answer:
vinegar and soap
Explanation: just took the test
How many grams of oxygen gas will be produced when 2.50 moles of potassium chlorate is decomposed?
Answer:
[tex]m_{O_2}=120gO_2[/tex]
Explanation:
Hello!
In this case, since the decomposition of potassium chlorate is:
[tex]2KClO_3\rightarrow 2KCl+3O_2[/tex]
We can see a 2:3 mole ratio between potassium chlorate and oxygen (molar mass 32.0 g/mol), thus, via stoichiometry, we compute the mass of oxygen that are produced by the decomposition of 2.50 moles of this reactant:
[tex]m_{O_2}=2.50molKClO_3*\frac{3molO_2}{2molKClO_3} *\frac{32.0gO_2}{1molO_2}\\\\m_{O_2}=120gO_2[/tex]
Best regards!
Calculate the volume in milliliters of 1.57 M potassium hydroxide that contains 10.3 g of solute.
Answer:
[tex]V = 0.117 \ L[/tex]
General Formulas and Concepts:
Chem
Reading a Periodic TableWriting compounds and polyatomic ionsMolarity = moles of solute / liters of solutionExplanation:
Step 1: Define
1.57 M KOH (potassium hydroxide)
10.3 g KOH
Step 2: Define conversions
Molar Mass of K - 39.10 g/mol
Molar Mass of O - 16.00 g/mol
Molar Mass of H - 1.01 g/mol
Molar Mass of KOH - 39.10 + 16.00 + 1.01 = 56.11 g/mol
Step 3: Convert
[tex]10.3 \ g \ KOH(\frac{1 \ mol \ KOH}{56.11 \ g \ KOH} )[/tex] = 0.183568 mol KOH
Step 4: Solve for Volume
Substitute: [tex]1.57 \ M=\frac{0.183568 \ mol}{x \ L}[/tex]Move x: [tex]x1.57 \ M=0.183568 \ mol[/tex]Isolate x: [tex]x=\frac{0.183568 \ mol}{1.57 \ M}[/tex]Evaluate: [tex]x=0.116922 \ L[/tex]Step 5: Check
We are given 3 sig figs. Follow sig fig rules.
[tex]0.116922 \ L \approx 0.117 \ L[/tex]
A sample of 6.44 g of napthalene (C10H8) is dissolved in 80.1 g of benzene (C6H6). Calculate the percent by mass of napthalene in this solution.
Answer:
7.44%
Explanation:
[tex]\frac{6.44}{6.44+80.1} *100=7.44[/tex]