Answer:
0.4323 ; 1.5394
Explanation:
Given that :
Specific gravity of Fibre (Sf) = 2.5
Specific gravity of Matrix (Sm) = 1.2
Mass of Fibre, Mf = 2.595g
Weight of composite specimen in water , Wc = 1.636g
Composite weight, Ww = 3.697 g
Weight of Fibre and matrix
Volume fraction of Fibre and matrix :
[(Mf/Sf) ÷ (Mf/Sf + Wc/Sm)] * 100
[(2.595/2.5) ÷ (2.595/2.5 + 1.636/1.2)]
(1.038 ÷ 2.4013333)
= 0.43225986
= 0.4323
2.)
Theoretical density of composite :
Weight of composite / (Mf/Sf + Wc/Sm)
3.697 / (2.595/2.5 + 1.636/1.2)
3.697 / 2.4013333
= 1.5395613
= 1.5394
The elements listed in the periodic table account
for only this percentage of the matter in
the universe.
Answer:
Only 4 %
Explanation:
Just about 4 percent of the known universe overall mass consists of atomic nuclei and is therefore described by chemical components. This proportion is around 15 percent of the total mass, with dark energy becoming the majority of the material .
Atmospheric pressure decreases as altitude increases. In other words, there is more air pushing down on you at sea level, and there is less air pressure pushing down on you when you are on a mountain.
If hexane (C6H14C6H14), octane (C8H18C8H18), and octanol (C8H17OHC8H17OH) are heated evenly at different altitudes, rank them according to the order in which you would expect them to begin boiling.
A) Hexane at high altitude.B) Octane at high altitude.C) Octane at sea level.D) Octanol at sea level.
Answer:
Octanol at sea level> Octane at sea level > Octane at high altitude > Hexane at high altitude
Explanation:
Let us have it behind our minds that the boiling points of alkanes depends on the length of the alkyl chain. The longer the chain length, the higher the boiling point of the alkane.
Also, octanol has hydrogen bonding between its molecules in addition to dispersion forces, hence it has a higher boiling point than octane and hexane at sea level.
So, the order of boiling points required at the specified altitudes is;
Octanol at sea level> Octane at sea level > Octane at high altitude > Hexane at high altitude
Help ASAP please
Which statement best describes the reaction pathway graph for an exothermic reaction but not an endothermic reaction?
It has a hill in the middle that is the highest point.
It has a valley in the middle that is its lowest point.
The reactants are higher in energy than the products.
The products are higher in energy than the reactants.
Answer: C ) The reactants are higher in energy than the products
Explanation:
The enthalpy that is a state variable that identifies the content of heat. Then the change of enthalpy for the exothermic reactions is negative, meaning that the energy of the products is lower than the energy of the reactants.
It’s a simple question in Welding when you use a torch if you add a lot of oxygen to the fuel what happens does it burn faster or what I want to know
Answer:
Easy, the flame is smaller but burns hotter.
Explanation:
What is the mass in grams of 2.21 mole of Ca3(PO4)4?
Answer:
1105.29 grams
Explanation:
If you calculate the molar mass of Ca3(PO4)4 you'll get 500.13. Molar mass is the mass of one mole of a substance. Multiply 500.1194 by 2.21 because we have 2.21 moles to get 1105.264 grams.
The molar mass of Ca is 40.078 grams, and there are 3 of them. So 40.078 x 3 is 120.234 grams.
The molar mass of P is 30.974 and there are 4 P's, so 30.974 x 4 is 123.896 grams.
The molar mass of O is 16 grams and there are 6 of them. Again, 16 x 16 is 256 grams.
Add up 120.234 + 123.896 + 256 to get the molar mass of Ca3(PO4)4, 500.13.
A sample equal to the atomic mass of an element in grams contains ________ atoms. This amount of matter is called _________ .
Explanation:
The mole (abbreviated mol) is the SI measure of quantity of a “chemical entity,” such as atoms, electrons, or protons. It is defined as the amount of a substance that contains as many particles as there are atoms in 12 grams of pure carbon-12.
Hope this Helped :)
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A student dissolved 5g of table salt in 100 mL of water in a beaker. When you compare the total mass of the salt and water before mixing to the mass of the solution after mixing, which is true?
A. The total mass of the solution after mixing, Will increase by a large amount
B. The total mass of the solution after mixing, Will increase by a small amount
C. The total mass of the solution after mixing will neither increase nor decrease
D. The total mass of the solution after mixing, Will decrease by a small amount
Answer:
B.
Explanation:
Answer:
B is the correct answer
Explanation:
At STP, adding salt to a 200 mL sample of water produces a saturated 1.7 M solution. How many grams of salt (NaCl) must be added to 200 mL to produce this solution?
Answer:
[tex]m_{NaCl}=19.9gNaCl[/tex]
Explanation:
Hello!
In this case, since the formula for the calculation of molarity is:
[tex]M=\frac{n}{V}[/tex]
Whereas we can compute the moles of the solute as shown below, making sure the volume is in liters:
[tex]n=M*V[/tex]
Thus, by plugging in we obtain:
[tex]n=0.200L*1.70mol/L=0.170molNaCl[/tex]
Next, since the molar mass of NaCl is 58.44 g/mol, we obtain the following mass:
[tex]m_{NaCl}=0.170molNaCl*\frac{58.44gNaCl}{1molNaCl}\\\\m_{NaCl}=19.9gNaCl[/tex]
Best regards!
Sam noticed on a climate map that most of the areas with high rainfall and a tropical climate were located in one region. Why are all the rainy, tropical areas found at a similar latitude? Describe the factors that influence the climate in this location.
Answer:
Okay here's the answer ↓
Step-by-step explanation:
Tropical climate is one of the five major climate groups in the Köppen climate classification. Tropical climates are characterized by monthly average temperatures of 18 ℃ (64.4 ℉) or higher year-round and feature hot temperatures. Annual precipitation is often abundant in tropical climates, and shows a seasonal rhythm to varying degrees. There are normally only two seasons in tropical climates, a wet season and a dry season. The annual temperature range in tropical climates is normally very small. Sunlight is intense because they are receiving direct sunlight.
In the presence of an acid catalyst, cyclohexanol (100.16 g/mol) is dehydrated to give cyclohexene (82.14 g/mol) and water. Reaction scheme illustrating the dehydration of cyclohexanol in the prescence of acid catalyst to cylcohexene and water. A dehydration reaction starting with 4.1 g cyclohexanol produces 3.0 g cyclohexene. Calculate the percent yield for this reaction. Report your answer with two significant figures.
Answer:
88%
Explanation:
Step 1: Write the balanced equation
C₆H₁₁OH ⇒ C₆H₁₀ + H₂O
Step 2: Calculate the moles corresponding to 4.1 g of C₆H₁₁OH
The molar mass of C₆H₁₁OH is 100.16 g/mol.
4.1 g × 1 mol/100.16 g = 0.041 mol
Step 3: Calculate the theoretical yield, in moles, of C₆H₁₀
The molar ratio of C₆H₁₁OH to C₆H₁₀ is 1:1. The theoretical yield of C₆H₁₀, in moles, is 1/1 × 0.041 mol = 0.041 mol.
Step 4: Calculate the mass corresponding to 0.041 moles of C₆H₁₀
The molar mass of C₆H₁₀ is 82.14 g/mol.
0.041 mol × 82.14 g/mol = 3.4 g
Step 5: Calculate the percent yield of C₆H₁₀
We will use the following expression.
percent yield = experimental yield/theoretical yield × 100%
percent yield = 3.0 g/3.4 g × 100% = 88%
Help solve please, it’s due in less than an hour or so.
sorry i can only figure out 1 but the answer is
------------------------------------------------------------------
124
hope you do good on your test :D
A species is
O the least specific group
O not a group at all
o the most specific group
the largest group
Starting in the mouth, food follows a pathway through the digestive system. Describe how the mouth is involved in both mechanical and chemical digestion. (At least one paragraph)
Answer:
The mouth uses both mechanical and chemical digestion. Mechanical digestion involves physically breaking down the food into smaller pieces (using the jaw/teeth). However, chemical digestion then takes over and starts breaking down the food into simpler nutrients that can be used by the cells using saliva, which is naturally made within the mouth.
Hope this helps you! Have a great day! :D
Convert 77.2 grams of CH4 to molecules.
Answer:
сфоткай отправь. я не магу зделать
According to the concept of Avogadro's number, there are 29.056×10²³ molecules in 77.2 g of methane.
What is Avogadro's number?Avogadro's number is defined as a proportionality factor which relates number of constituent particles with the amount of substance which is present in the sample.
It has a SI unit of reciprocal mole whose numeric value is expressed in reciprocal mole which is a dimensionless number and is called as Avogadro's constant.It relates the volume of a substance with it's average volume occupied by one of it's particles .
According to the definitions, Avogadro's number depend on determined value of mass of one atom of those elements.It bridges the gap between macroscopic and microscopic world by relating amount of substance with number of particles.
Number of atoms can be calculated using Avogadro's number as follows: mass/molar mass×Avogadro's number
In the given example, number of moles=77.2/16=4.825 moles
If 1 mole has 6.023×10²³ molecules , then 4.825 moles will have 4.825×6.023×10²³ /1=29.056×10²³ molecules .
Thus, there are 29.056×10²³ molecules in 77.2 g of methane.
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The density of copper is listed as 8.94 g/mL. Two students each make three density determinations through experimentation. Student A's measurements are 6.3 g/mL, 8.9 g/mL, and 11.1 g/mL. Student B's measurements are 8.3 g/mL, 8.2 g/mL, and 8.4 g/mL. Compare the two sets of results in terms of precision and accuracy.
Answer:A) After the values are added, we determine how many significant figures are involved by looking at the decimal places of the original values. 52.13 had only 2 digits past the decimal point so the answer can only contain 2 significant numbers after the decimal point which would be 53.88 g
Explanation:
3. What role did the government play in either supporting or suppressing African Americans'/Blacks'
civil rights?
Which individual elements make up the following common
compounds?
CaCO 3
CaCl 2
C H O 3 6
HCl
Ca(OH) 2
Answer:
I think it will carbon hope it helps
What would be the volume of mercury sample that has a mass of 52.757 g? The density of mercury is 12.5g / mL .
Answer:
Explanation:
Divide the mass by the density and the units of grams will cancel so youll end up with mL.
(52.757g)/(12.5g/mL) = 4.2mL
In a disproportionation reaction, the disproportionate substance
A. has exactly one oxidation state.
B. has exactly two oxidation states.
C. has at least three oxidation states.
D. has either one or two oxidation states.
Answer:
The answer is C: has at least three oxidation states.
Explanation:
you're welcome
Answer:
C
Explanation:
got it right on Edge
Sodium sulfate forms several hydrates. A sample of one of these hydrates is heated until all the water is removed. What is the formula of the original hydrate if it loses 43% of its mass when heated?
Answer:
Na₂SO₄•(H₂O)₆.
Explanation:
The mass that is lost when the sample is heated is water.
Let's assume we have 100 g of the hydrate:
43 grams would be water (H₂O), while the rest (100-43=57) would be sodium sulfate anhydrous (Na₂SO₄).
We convert both those masses to moles, using their respective molar masses:
H₂O ⇒ 43 g ÷ 18 g/mol = 2.39 molNa₂SO₄ ⇒ 57 g ÷ 142.04 g/mol = 0.40 molWe can write those results as (Na₂SO₄)₀.₄₀•(H₂O)₂.₃₉. Now we just need to multiply those numbers so that they become integers.
If we multiply both coefficients by 5 we're left with (Na₂SO₄)₂•(H₂O)₁₂.
Simplify and thus the final answer is Na₂SO₄•(H₂O)₆.
If 1 teaspoons of vinegar are equivalent in 60 drops. How many drops of vinegar are there in
1 ½ teaspoons?
Answer:
90 drops
Explanation:
1 teaspoon = 60 drops
Half a teaspoon = 60 ÷ 2 = 30 drops
1 and a half = 60 + 30 = 90
Which upgrade to a school will most likely reduce the school's consumption of
nonrenewable resources?
Answer: if they use solar collection panels
Explanation:
An extraction procedure specifies that an aqueous solution containing dissolved organic material be extracted twice with 10 mL portions of diethyl ether. A student removes the lower layer after the first extraction and adds the second 10 mL portion of ether to the remaining upper layer. After shaking the separatory funnel, the student observes only one liquid phase with no interface. Explain.
Answer: The student observed only one liquid phase because The student removed the aqueous layer instead of the organic layer and then added organic solvent to more organic layer. Diethyl ether is less dense than water.
Explanation:
In organic chemistry, which is the chemistry of carbon atoms, liquid-liquid extraction techniques are used to separate solutes from its crude reaction mixtures. An example of liquid- liquid extraction technique used is the Separatory funnel.
The Separatory funnel extraction technique allows the separation of solutes based on their solubilities in two immiscible liquids. This appears as two phases or layers with the organic solvent on top while the aqueous solution is below the funnel. This is because the organic solvents are less dense than the aqueous solution.
From the question, the student had a dissolved organic compound in an aqueous solution and was given an organic solvent, diethyl ether for its extraction. When the first 10ml of ether was added, the dissolved organic compound mixed with it and remained in the top layer of the mixture. The student removes the lower layer after the first extraction and adds the second 10mL portion of ether to the upper layer remaining in the separatory funnel. After shaking the funnel, the student observes only one liquid phase with no interface because more organic solvent was added to the organic layer that remained after the aqueous layer was removed.
Menstruation occurs on a ______ interval from puberty until menopause
A. Three months
B. Two months
C. Half month
D. One month
if you start with 4.3 moles of NH3, how many moles of NANH2 can be produced
Explanation:
Mole ratio of NH3 to NaNH2 = 2 : 2.
Moles of NaNH2 produced
= 4.3mol * (2/2) = 4.3mol.
As human populations grow, it becomes more important to use renewable sources of energy Which of the following objects uses energy from a renewable source?
a stove that is powered by natural gas
a refrigerator that runs on solar power
a lantern that burns oil from beneath Earth's surface
a foaster that uses electricity from a coal-burning power plant
Explanation:
Moreover, increasing use of fossil fuels also causes serious environmental problems. Hence, there is a pressing need to use renewable energy sources like solar energy, wind, tide, biomass and energy from waste material. (i) it reduces the dependence on fossil fuels for energy. (ii) they donot produces pollution.
how is the massive star born
If an oxygen molecule is moving at 4.78 x 104
cm.s-, what is its speed in mi hrl?
Show work please
Answer: 1075.5 mph
Explanation:anything moving at 4.78*10^4 cm/sec
equivalent to
cm —> miles = 1/1.6*10^5
sec —> hr = 1/3600
[4.78*10^4]*3600/1.6*10^5 = 1075.5 mph
which type of electromagnetic radiation is used in security baggage scanners
X-rays, because
I did it and got it right
Answer:
XX-rayX-ray
Explanation:
The graph below shows a reaction to which a catalyst has been added. How would the graph be different if it showed the same reaction without a catalyst?
A. The width of region 2 would be smaller.
B. The difference in the heights of regions 1 and 3 would be larger.
C. The height of region 2 would be larger
D. The distance between regions 1 and 3 would be smaller
Answer:
a. the width of region 2 would be smaller
If the same reaction was shown without a catalyst, the height of region 2 would be larger, so the correct option is (C).
What is catalyst?A catalyst is a substance that speeds up the rate of a chemical reaction without being consumed in the process. It works by providing an alternate pathway for the reaction with a lower activation energy, making it easier for the reactants to transform into products.
Catalysts can be solids, liquids, or gases, and they can be homogeneous or heterogeneous, depending on whether they are in the same phase as the reactants or in a different phase.
Catalysts are widely used in many industrial processes, such as the production of fertilizers, plastics, and fuels, to increase the efficiency and reduce the cost of the reaction. They can also be found in biological systems, where they play a crucial role in metabolic processes, such as the breakdown of food in the digestive system or the conversion of light into chemical energy in photosynthesis.
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