Answer:
21 molecules of water.
Explanation:
The polymerization of a 22-monomer long cellulose molecule will require 21 molecules of water. This is because the polymer bond is formed when the -OH group from the 1st monomer of the glucose unit and the H group from the 2nd monomer gets removed as a water molecule. This process is termed to be a condensation reaction.
at a particulat temperature, a smaple of pure water has a Kw of 7.7x10-14. what is the hydroxide concentration of this sample
Answer: The hydroxide concentration of this sample is [tex]3.85\times 10^{-7}[/tex]
Explanation:
When an expression is formed by taking the product of concentration of ions raised to the power of their stoichiometric coefficients in the solution of a salt is known as ionic product.
The ionic product for water is written as:
[tex]K_w=[H^+]\times [OH^-][/tex]
[tex]7.7\times 10^{-14}=[H^+]\times [OH^-][/tex]
As [tex][H^+]=[OH^-][/tex]
[tex]2[OH^-]=7.7\times 10^{-14}[/tex]
[tex][OH^-]=3.85\times 10^{-7}[/tex]
Thus hydroxide concentration of this sample is [tex]3.85\times 10^{-7}[/tex]
A substance made up of two or more types of atoms that are NOT chemically combined is called a(n)
A
element
B
mixture
с
compound
D
pure substance
Answer:
pure substance
Explanation:
it does not combine to anything.
What would be the mass of 9.03 x 10^21 molecules of hydrobromic acid?
1.21 g HBr
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightChemistry
Compounds
Writing CompoundsAcids/BasesAtomic Structure
Reading a Periodic TableUsing Dimensional AnalysisAvogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.Explanation:Step 1: Define
9.03 × 10²¹ molecules HBr
Step 2: Identify Conversions
Avogadro's Number
Molar Mass of H - 1.01 g/mol
Molar Mass of Br - 79.90 g/mol
Molar Mass of HBr - 1.01 + 79.90 = 80.91 g/mol
Step 3: Convert
Set up: [tex]\displaystyle 9.03 \cdot 10^{21} \ molecules \ HBr(\frac{1 \ mol \ HBr}{6.022 \cdot 10^{23} \ molecules \ HBr})(\frac{80.91 \ g \ HBr}{1 \ mol \ HBr})[/tex]Multiply/Divide: [tex]\displaystyle 1.21325 \ g \ HBr[/tex]Step 4: Check
Follow sig fig rules and round. We are given 3 sig figs.
1.21325 g HBr ≈ 1.21 g HBr
_______________ is a process by which organisms best fit for the environment are most likely tp survive and reproduce
Answer:
natural selection
Explanation:
natural selection
Please help me thanks so much....I’ll mark you?!?!:)))) ( 15 points)
Answer:
all of the above
Explanation:
Which of the following is not a natural change to the envlronment? drought , flood, disease ranching
Answer:
Disease ranching
Explanation:
Floods and Droughts are caused by the enviorment. Diseases are but a product and don't affect the enviorment.
Answer:
disease ranching is not a natural change to the environment .
Explanation:
This all happen because of human activities
A student is investigating potential and kinetic energy by stretching a spring across a table. When the student lets go
The spring recoils.
Answer: When the spring is recoiling
Explanation:
Answer:
When the spring is recoiling
Explanation:
The frequency of the stretching vibration of a bond in IR spectroscopy depends on what two quantities?
Answer:
Strength of the bond
Masses of the bonded atoms.
Explanation:
The lack of such groups means that they are not endogenous in the concentrate. 1. A bond's spreading frequency relies on the frequency of the bond and the concentrations of the atoms that are bonded.
what problems occurs if the firework mixture is not pure(they are dirty or contaminated?
Firework mixture is made up with potassium nitrate and other toxic chemicals. They produce harmful wastes to the atmosphere. If they are contaminated, they make release very dangerous explosives by unwanted reactions.
What are explosives?Explosives are chemicals releasing lot of heat energy to the surrounding upon decomposition. Nitrogen compounds, hydrogen etc are explosive and they will explode in air or water.
Chemicals have to handled carefully and stored as per the conditions based on their chemical and physical properties. Some of them may easily corrode. Some may rapidly reacts with water or air and some may explode in air.
Explosive chemicals causes atmospheric pollution as well as health risk by releasing hazardous chemicals. If they are contaminated then there may occur some unwanted reaction and it will make the risk intense by producing toxic gases.
To find more about explosives, refer here:
https://brainly.com/question/8735140
#SPJ2
The isotope carbon-14 decays over time into nitrogen-14 with a half-life of 5,730 years. Suppose that you find a fossil that contains 1.25 grams of carbon-14 and 3.75 grams of nitrogen-14. How old is the fossil
Answer:
11460 years
Explanation:
0.693/t1/2 = 2.303/t log (No/N)
t1/2 = half life of the carbon
t = age of the fossil
No= amount of radioactive material originally present
N= amount of radioactive material present at time=t
No= mass of carbon + nitrogen = 5g
0.693/5730 = 2.303/t log (5/1.25)
1.21 ×10^-4 = 1.3866/t
t= 1.3866/1.21 ×10^-4
t= 11460 years
which element is the least reactive? Neon, Chlorine, Gallium or Tin
Help it is easy I think
Why must scientific investigations be replicable?
A ) to prove the reliability of the results
B)to confirm ideas and theories
C)to prove its validity within the scientific community
D)to improve the investigation each time
Answer:a
Explanation:
Answer:
Answervis A.
Explanation:
Because,so that other scientists can validate the results.
I hope it's helpful!
How many grams are in 4.7 moles of Na2O?
290 g Na₂O
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightChemistry
Atomic Structure
Reading a Periodic TableUsing Dimensional AnalysisExplanation:Step 1: Define
4.7 mol Na₂O
Step 2: Identify Conversions
Molar Mass of Na - 22.99 g/mol
Molar Mass of O - 16.00 g/mol
Molar Mass of Na₂O - 2(22.99) + 16.00 = 61.98 g/mol
Step 3: Convert
Set up: [tex]\displaystyle 4.7 \ mol \ Na_2O(\frac{61.98 \ g \ Na_2O}{1 \ mol \ Na_2O})[/tex]Multiply: [tex]\displaystyle 291.306 \ g \ Na_2O[/tex]Step 4: Check
Follow sig fig rules and round. We are given 2 sig figs.
291.306 g Na₂O ≈ 290 g Na₂O
I’ve missed this question twice now. Please help
Answer:
then it only gotta be 2 other options .
Explanation:
The process by which cells divide is called
A
O replication
B.
mitosis
C.
respiration
D.
photosynthesis
the answer is mitosis
Compare What do infrared technologies, fiber optic
technologies, and satellite technologies all have in
common?
Answer:
ptic fiber communication and satellite communication are the leading technologies which are revolutionizing the world of telecommunications. Both technologies have their advantages and limitations which make them suitable for certain type of applications. This article will provide an overview of optic fiber and satellite communication technologies and present a comparison of the features and related issues.
Optic Fiber Communication
Optic Fiber communication transmits information by sending pulses of light (using laser) through an optic fiber. The low signal loss in optic fibers and high data rate of transmission systems, allow signals with high data rates (exceeding several Gbps) to travel over long distances (more than 100 km) without a need of repeater or amplifier. Moreover, using wavelength division multiplexing (WDM) allows a single fiber to carry multiple signals (upto 10 different signals) of multi-Gbps transmissions. Optic Fiber communication offers extremely high bandwidth, immunity to electromagnetic interference, non-existent delays and immunity from interception by external means. In the 1980s and 1990s, the continents were linked together using undersea optic fiber bringing about a paradigm shift in the global telecommunications.
These advancements in optic fiber communication has resulted in decrease of satellite communications for several types of communications. For instance, transmission between fixed locations or point-to-point communications, where large bandwidths are required (such as transoceanic telephone systems) are made through optic fiber instead of using satellite communication. Optic Fiber communication is also used to transmit telephone signals, Internet communication, LAN (Gigabit LAN) and cable television signals.
Satellite Communication
Satellite communications use artificial satellites as relays between a transmitter and a receiver at different locations on Earth. Satellite systems allow users to bypass typical carrier offices and to broadcast information to multiple locations. Communications satellites are used for radio, TV, telephone, Internet, military and other applications. There are more than 2,000 satellites around Earth’s orbit, being used for communication by both government and private organizations.
Communication Satellites are LOS (line-of-sight) microwave systems with a repeater. These satellites rotate around the earth with the speed of earth and are known as geostationary satellites. The limitations of antenna size also limits focusing capability making the coverage for a single satellite transmitter very large. This makes satellite communication ideal for TV and radio services as the signal has to flow from a single point to many points in a single direction. The large distance of satellites from the earth (about 22,300 miles) results in delays which adversely effects two-way communication like mobile conversations. Low earth orbit satellites can be used for two-way mobile communication because less power is required to reach those satellites.
Explanation:
7. Which of the following is not a characteristic of a solution?
a. It is a uniform mixture
b. It will scatter a beam of light
c. The solute and solvent cannot be distinguished by the naked eye
d. The solute particles cannot be separated by filtering
How does an objects speed affect its kinetic energy?
What causes a spectrum of colors to appear when light moves through a prism?
Absorption of light waves
O Refraction of light waves
Transmission of light waves
Reflection of light waves
Answer:
It is refracted out, B
Explanation:
When the light travels through the prism, it refracts the colors out of it. In which a rainbow sort coloration is released from the other side.
Answer:
Explanation:
Refraction of light waves
The number of light waves that occur in one second is known as the wave's
Question 2 options:
amplitude
frequency
energy
movement
Answer:
b
Explanation:
I did this quiz and i think a got it right i also looked up my answer to make sure it was right good luck on quiz :)
what is the periodic table elements
Answer:
Here is a picture of all the elements
Answer:
The periodic table is a tabular array of the chemical elements organized by atomic number, from the element with the lowest atomic number, hydrogen, to the element with the highest atomic number, oganesson. The atomic number of an element is the number of protons in the nucleus of an atom of that element.
Explanation:
PLEASE MARK ME AS BRAINLIEST
how does heat transfer into conduction
Explanation:
Heat is transferred by conduction when adjacent atoms vibrate against one another or electrons move from one atom to another . Conduction is the most significant meanings of heat transfer within a solid or between solid objects informal contact.
Which of the following chemical equations proves that the law of conservation of mass is in effect?
Question 2 options:
Mg2 + LiBr ---> LiMg + Br
2KCl + F2 ---> 2KF + Cl2
Na +O2 ---> Na2O
H20 ---> H2 + O2
Answer:
2KCl + F₂ → 2KF + Cl₂
Explanation:
Law of conservation of mass:
According to the law of conservation mass, mass can neither be created nor destroyed in a chemical equation.
This law was given by French chemist Antoine Lavoisier in 1789. According to this law mass of reactant and mass of product must be equal, because masses are not created or destroyed in a chemical reaction.
For example:
2KCl + F₂ → 2KF + Cl₂
In this equation mass of reactant and product is equal. There are 2 potassium 2 chlorine and fluorine atoms on both side of equation it means mass remain conserved.
All other options are incorrect because mass is not conserved.
HELP I need these 2 questions answered
Answer:
1=a 2=d i think
Explanation:
How hot will a 2.5 L balloon have to get to expand to a volume of 5 L? Assume that the initial temperature of the balloon is 22 C?
The final temperature : 317 °C
Further explanationGiven
V₁=2.5 L
V₂ = 5 L
T₁ = 22 + 273 = 295 K
Required
The temperature, T₂
Solution
Charles's Law
When the gas pressure is kept constant, the gas volume is proportional to the temperature
[tex]\tt \dfrac{V_1}{T_1}=\dfrac{V_2}{T_2}[/tex]
Input the value :
T₂ = (T₁ x V₂) : V₁
T₂ = (295 x 5) : 2.5
T₂ = 590 K = 317 °C
An aqueous solution of 6.70 M ammonia, NH3, has a density of 0.950 g/mL. The percent by mass of NH3 in the solution is %.
Answer:
12.01% by mass
Explanation:
Percent by mass is 100 times the mass of solute (ammonia) over the mass of the solution. In molarity, we have the moles of ammonia per liter of solution. There are 6.70moles of NH3 in 1L. Thus, we need to convert the moles of ammonia to grams and the liters of solution to grams:
Mass ammonia - Molar mass: 17.031g/mol-
6.70moles * (17.031g / mol) = 114.1g NH₃
Mass solution:
1L * (1000mL / 1L) = 1000mL * (0.950g/mL) = 950g
Percent by mass:
114.1g NH₃ / 950g * 100 =
12.01% by massClassify each solvent as protic or aprotic. a. (CH3)2CHOH c. CH2Cl2 e. N(CH3)3 b. CH3NO2 d. NH3 f. HCONH2
Answer:
The protic solvents are (CH3)2CHOH, NH3, and HCONH2
The aprotic solvent are CH3NO2, CH2Cl2, and N(CH3)3
Explanation:
A protic solvent is a solvent that has a hydrogen atom bound to an oxygen (O), a nitrogen (N), or fluoride (F). Generally, any solvent that contains a labile H⁺ is called a protic solvent.
a. (CH3)2CHOH
(CH3)2CHOH is a protic solvent because one of the hydrogens is bound to oxygen (O)
b. CH3NO2
CH3NO2 is an aprotic (i.e not a protic solvent) solvent because all the hydrogens are bound to carbon.
c. CH2Cl2
CH2Cl2 is an aprotic solvent because all the hydrogens are bound to carbon.
d. NH3 is a protic solvent because all the hydrogens are bound to Nitrogen (N)
e. N(CH3)3 is an aprotic solvent because all the hydrogens are bound to carbon
f. HCONH2 is a protic solvent because two of the hydrogens are bound to Nitrogen (N)
Assume you mixed 5 µl of your cod fish homogenate with 195 µl working solution. The fluorometer displays a measurement of 12.2 µg/ml. What is the protein concentration of the cod fish homogenate?
Answer:
Hallo
Explanation:
I took that question
Touching a hot stove or the melting of ice in your hand (as you squeeze it) is an example of
Answer: conduction
Explanation:
the heat passes out of the stove and into your hand. So is holding an ice cube – the heat is conducted out of your hand, and into the ice cube (that’s why your hand feels cold).
Answer:
Conduction
Explanation:
Conduction occurs when objects touch. The heat from the warmer object is transferred to the cooler object, eventually evening out the temperatures.
The half-life of sodium-24 is 15 days. A laboratory technician measures out a 72 g sample. Approximately how many grams of sodium-24 would remain after 45 days?
Answer:
after 45 days 9 g left
Explanation:
Given data:
Half life Na-24 = 15 days
Mass of sample = 72 g
Mass remain after 45 days = ?
Solution:
Number of half lives passed:
Number of half lives = time elapsed / half life
Number of half lives = 45 days / 15 days
Number of half lives = 3
At time zero total amount = 72 g
After first half life = 72 g/ 2= 36 g
At 2nd half life = 36 g/2 = 18 g
At 3rd half life = 18 g/2 = 9 g
Thus after 45 days 9 g left.