How many electrons are represented by a dash (-) in a lewis dot structure compound?
A. 2
B. 4
C.3
D. 1
calculate the concentration of the solution produced when a 3.2g of sodium chloride is
issolved in 8dm of water.
Answer:
The concentration of the 3.2 g of sodium chloride in 8 dm³ of water is 6.845 × 10⁻³ M
Explanation:
The concentration of a solution is given as either the ratio of mass to volume, or the ratio of volume to volume or as molarity
[tex]Concentration, C = \dfrac{Mass}{Volume} = \dfrac{Volume}{Volume} = \dfrac{Number \ of \ moles }{Liters \ of \ solution}[/tex]
The number of moles present in 3.2 g of sodium chloride, 'n', is given as follows;
[tex]n = \dfrac{Mass}{Molar \ mass}[/tex]
The molar mass of sodium chloride, NaCl = 58.44 g/mol
n = 3.2 g/58.44 g/mol = 0.0547570157 moles
8 dm³ = 8 Liters
Therefore, the concentration, C = 0.0547570157 moles/(8 liters) = 6.845 × 10⁻³ M
The concentration of the 3.2 g of sodium chloride in 8 dm³ of water = 6.845 × 10⁻³ Molar solution.
How does circulation help maintain body temperature?
Answer:
Answer Below
Explanation:
Your feet and hands are thin compared to the rest of your body. Thin stuff has a large surface area compared to volume. Surface area is where you lose heat and volume is where you generate heat. Because of this, they lose heat quickly and do not generate enough heat to stay warm. To fix this your body also moves heat around from your warm core to your hands and feet using your blood. Your blood is warm. It gets to be that way because it runs through areas, mostly in your torso, that are always warm
Elements o fb the same group have the same chemical properties
Answer:
The chemical elements are arranged in order of increasing atomic number. The horizontal rows are called periods and the vertical columns are called groups. Elements in the same group have similar chemical properties. This is because they have the same number of outer electrons and the same valency.
Which of the following is not a type of covalent bond?
A. Polar
B. Double
C. Non-polar
D. Quadruple
Answer:
letter b
Explanation:
I dunno if I'm right cuz I'm just a grade five sorry if this can't help
How many molecules are there in 0.655 moles of C6H14
Answer:
[tex]\boxed {\boxed {\sf 3.94 *10^{23} \ molecules \ C_6 H_ {14} }}}[/tex]
Explanation:
1 mole of any substance has the same number of particles: 6.022 * 10²³. This number is as Avogadro's Number.
The particles can be molecules, atoms, formula units, etc. For this problem, the particles are molecules of C₆H₁₄ or hexane.
We can set up a ratio using Avogadro's Number.
[tex]\frac {6.022 *10^{23} \ molecules \ C_6H_{14}}{1 \ mol \ C_6H_{14}}[/tex]
Multiply by the given number of moles: 0.655
[tex]0.655 \ mol \ C_6H_{14} * \frac {6.022 *10^{23} \ molecules \ C_6H_{14}}{1 \ mol \ C_6H_{14}}[/tex]
The moles of hexane will cancel, because one is the "numerator" (techincally 0.655 is over 1) and the other is in the denominator of the ratio.
[tex]0.655 * \frac {6.022 *10^{23} \ molecules \ C_6H_{14}}{1 }[/tex]
[tex]0.655 * {6.022 *10^{23} \ molecules \ C_6H_{14}}[/tex]
[tex]3.94441*10^{23} \ molecules C_6H_{14}[/tex]
The original value of moles has three significant figures, so our answer must have the same. For the number we found, that is the hundredth place.
3.94441The 4 in the thousandth place tells us to leave the 4 in the hundredth place.
[tex]3.94 *10^{23} \ molecules \ C_6H_{14}[/tex]
0.655 moles of hexane is equal to approximately 3.94 *10²³ molecules of hexane.
A gas initial volume and pressure is 5m^3 and 101320 Pa and allows to expand up to 12m^3 then what is the final pressure?
Answer:
New pressure = 42216.66 Pa
Explanation:
Given that,
Initial volume, V₁ = 5 m³
Final pressure, P₁ = 101320 Pa
Final volume, V₂ = 12 m³
We need to find the final pressure of the gas. We know that the relation between pressure and volume is given by :
[tex]P\propto \dfrac{1}{V}\\\\P_1V_1=P_2V_2\\\\P_2=\dfrac{P_1V_1}{V_2}\\\\P_2=\dfrac{101320 \times 5}{12}\\\\P_2=42216.67\ Pa[/tex]
So, the new pressure is equal to 42216.66 Pa.
What is the difference between the solid line and the dotted line?
Answer:
it is dotted
Explanation:
Which statement describes the endothermic reaction represented by this
graph?
Answer:
Option A, describes the endothermic reaction represented by this graph
Explanation:
In this graph the energy released (or the potential energy) at the time of product formation is lower than the potential energy of the reactants. Hence, additional energy input will be required to form the product. Thus, energy is absorbed during the reaction.
Option A is correct
Answer: energy is given off by the reaction
Explanation:
The half-life of radium-226 is 1,600 years. It decays into radon-222. What fraction of the original amount of radium-226 in a sample will still be radium
after 8,000 years?
A.1/8
B.1/4
c.1/32
D.1/16
Answer:
Your answer will be C. 1/32
Answer:
C. 1/32
Explanation:
Need help on this question asap pleasee I would really appreciate it
Answer:
See Explanation
Explanation:
An endothermic reaction is one in which energy is absorbed and the change in enthalpy for the reaction is positive.
If we look at the reaction 2HgO + 45kcal ----> 2Hg + O2; we will notice that
i) 45kcal of energy was taken in (absorbed) for the reaction to occur
ii) The value of the reaction enthalpy is positive
For these two reasons, the reaction is an endothermic reaction as written.
Instructions
Click the links to open the resources below. These resources will help you complete the assignment. Once you have created your file(s) and are ready to upload your assignment, click the Add Files button below and select each file from your desktop or network folder. Upload each file separately.
Now that the lab is complete, it is time to write your lab report. The purpose of this guide is to help you write a clear and concise report that summarizes the lab you have just completed.
The lab report is composed of four sections:
Section I: Experimental Overview
• Provide background information.
• Include the hypothesis(es).
• Summarize the procedures.
Section II: Data and Observations
• Summarize the data you collected in the lab guide.
• Include information from data tables.
• Include any written observations that are relevant.
Section III: Analysis and Discussion
• Discuss any important calculations or formulas used.
• Identify key results, what the results indicate, and any trends in the data.
• Include graphs (if constructed) that display trends in the data.
• Provide possible reasons for any problems with the experiment, or unexpected data.
Section IV: Conclusions
• Identify if the hypothesis(es) was (were) supported or refuted.
• Provide logical reasoning based on data.
• Explain how the experiment could be improved.
To help you write your lab report, you will first answer the questions listed below by reflecting on the experiment you have just completed. Then you will use the answers to these questions to write the lab report that you will turn into your teacher.
You can upload your completed report with the upload tool in formats such as OpenOffice.org, Microsoft Word, or PDF. Alternatively, your teacher may ask you to turn in a paper copy of your report or use a web-based writing tool.
Questions
Section I: Experimental Overview
• What is the purpose of the lab, the importance of the topic, and the question you are trying to answer?
• What is your hypothesis (or hypotheses) for this experiment?
• What methods are you using to test this (or each) hypothesis?
Section II: Data and Observations
• Locate the data and observations collected in your lab guide. What are the key results? How would you best summarize the data to relate your findings?
• Do you have quantitative data (numerical results or calculations)? Do you have qualitative data (written observations and descriptions)? How can you organize this date for your report?
Section III: Analysis and Discussion
• What do the key results indicate?
• If you constructed graphs, what trends do they indicate in your data?
• Were there any problems with the experiment or the methods? Did you have any surprising results?
Section IV: Conclusions
• What do the results tell you about your hypothesis(es)?
• How do the data support your claim above?
• If you could repeat the experiment and make it better, what would you do differently and why?
Just putting a comment here, I needed to test something
In the reaction below, 22 g of H2S with excess
O2 produced 5 g of sulfur.
? H2S + ? O2 → ? S + ? H2O .
What is the percent yield of sulfur?
Answer in units of %.
Answer:
24.1 %
Explanation:
This is the reaction of oxygen between hydrogen sulfide.
The equation is:
2H₂S + O₂ → 2S + 2H₂O
As the oxygen is the excess, limting reagent is the H₂S.
We convert the mass to moleS: 22g / 34.06 g/mol =
0.646 moles
Ratio is 2:2. 2 moles of sulfide can produce 2 moles of sulfur.
Then, 0.646 moles of sulfide will produce 0.646 moles of S.
We convert the moles to mass: 0.646 mol . 32.06 g/mol =
20.71 g
That's the theoretical yield.
% yield = (produced yield / theoretical yield) . 100
% yield = (5 g/ 20.71g) . 100 = 24.1 %
Hardness, high melting point, brittleness, non-conductivity, unsolubility in water,.....Are characteristics of ......?
Answer:
Covalent Network Solids
Explanation:
A covalent network solid or network solid is defined as the chemical compound in which the atoms are joined by a covalent bond in continuous network and it extends all through the material. There are no single molecules on a network solid, the whole crystal may be considered as a macromolecule.
Some of the characteristics of the covalent network solids are :
It is very hard.It is non conductive.It is highly brittle.It has high melting point.It is insoluble in water.Which activity is the best demonstration of J.J. Thomson’s use of creativity in his work?
Answer:
The correct answer is making observations in his experiment. In his cathode ray tube experiment J. J. Thomson proved that the cathode rays are indeed negatively charged particles.
The moon appears to change _________ over the course of the _______________.
Answer:
shape or size? over the course of the month
formula of atom bomb
Answer:
It says that the energy (E) in a system (an atom, a person, the solar system) is equal to its total mass (m) multiplied by the square of the speed of light (c, equal to 186,000 miles per second).
Explanation:
An inherited behavior or physical characteristics that helps an organism survive and reproduce Natural selection Predation Adaptation Competition
look at pic thanks :D
Answer:
it's natural selection
Explanation:
adaptation is when you adapt to some situation
A gas at 1.10 atm and 30.0°C fills a flexible container with an initial volume of 2.00 L. If the temperature is raised to 80.0°C and the pressure increased to 2.40 atm, what is the new volume?
Answer:
P1=1.10atm
V1=2.00L
T1=30.0+273=303
P2=2.40atm
V2=?
T2=80.0+273=353
Explanation:
V2=1.10*2.00*353=776.6
2.40*303=727.2
776.6/727.2=1.0679L
The new volume occupied by the of gas as its temeprature and pressure is raised is 1.07L.
Combined gas lawCombined gas law put together both Boyle's Law, Charles's Law, and Gay-Lussac's Law. It states that the ratio of the product of volume and pressure and the absolute temperature of a gas is equal to a constant.
It is expressed as;
P₁V₁/T₁ = P₂V₂/T₂
Given the data question;
Initila pressure P₁ = 1.10atmFinal pressure p₂ = 2.40atmInital temperature T₁ = 30.0°C = 303.15KFinal temperature T₂ = 80.0°C = 353.15KInitial Volume V₁ = 2.00LFinal Volume V₂ = ?To calculate the new volume that the gas occupy, we subtsitute our given values into the expression above.
P₁V₁/T₁ = P₂V₂/T₂
P₁V₁T₂ = P₂V₂T₁
V₂ = P₁V₁T₂ / P₂T₁
V₂ = ( 1.10atm × 2.00L × 353.15K ) / ( 2.40atm × 303.15K )
V₂ = 776.93LatmK / 727.56atmK
V₂ = 1.07L
Therefore, The new volume occupied by the of gas as its temeprature and pressure is raised is 1.07L.
Learn more about the combined gas law here: brainly.com/question/25944795
how many total atoms are there is a sugar molecule
Answer:
The white stuff we know as sugar is sucrose, a molecule composed of 12 atoms of carbon, 22 atoms of hydrogen, and 11 atoms of oxygen (C12H22O11). Like all compounds made from these three elements, sugar is a carbohydrate
Give the word and chemical equations (including state symbols) for the reaction of potassium and water
Zinc will displace copper from a solution of copper sulfate, and magnesium will displace zinc from a solution of zinc sulfate
a)Write full, balanced chemical equations for the two reactions using state symbols.
Answer:
Zinc is Zn and Magnesium is Mg
List three differences between the earth 240 million years ago and the present earth.
Select the correct arrows. Which arrows indicate weathering and erosion? sedimentary rocks metamorphic rocks igneous rocks
Answer:
igneous to sedimentary rock
Explanation:
Answer:
ingeous rocks to sedimentary rocks
which is the correct order of ease of carbon dioxide production by heating the group II metal carbonates?
Which is the correct order of ease of carbon dioxide production by heating the group II metal carbonates?
A) [tex]BaCO_{3} > SrCO_{3} > CaCO_{3} > MgCO_{3}[/tex]
B) [tex]MgCO_{3} > CaCO_{3} > SrCO_{3} > BaCO_{3}[/tex]
C) [tex]CaCO_{3} > MgCO_{3} > BaCO_{3} > SrCO_{3}[/tex]
D) [tex]SrCO_{3} > BaCO_{3} > CaCO_{3} > MgCO_{3}[/tex]
Answer:
Explanation:
The correct option is A:
[tex]BaCO_{3} > SrCO_{3} > CaCO_{3} > MgCO_{3}[/tex]
On the periodic table, carbonates required stronger heating as one does down the groupings in order for them to decompose. The implication is that the stability of compounds will increase from [tex]MgCO_{3}[/tex] to [tex]BaCO_{3}[/tex] .
So the carbonates will be stable according to the following order:
[tex]BaCO_{3} > SrCO_{3} > CaCO_{3} > MgCO_{3}[/tex], thus making B the correct answer.
Cheers
What actions could you take to increase the rate of solution for a solid solute that dissolves endothermically in 100g of water?
Answer:
We will increase the temperature for a solution to be dissolved more into water.
To form a solution, energy is required to break the particles. If more energy is required to break the bonds of solute and solvent than the energy is released, then its called endothermic reaction.
For an endothermic solution, we would have to provide heat / temperature (energy) so that more solute can be dissolved in water which can increase the rate of solution.
in an ionic bond:
A. both atoms share their electrons.
B. one atom accepts electrons from another.
C. The atoms attract each other but their electrons do not interact.
D. The atoms swap electrons
Some of the glucose required for cellular respiration in humans is obtained by??
Answer:
.
Explanation:
Some of the glucose required for cellular respiration in humans is obtained by external food source which are rich in carbohydrates.
What is cellular respiration?Cellular respiration is the process in which cells combines the oxygen with the foodstuff molecules, and converting the chemical energy into life sustaining activities as energy.
In the human body, we get the glucose for the cellular respiration from the external food source which are riched in carbohydrates, starch, etc. After converting the chemical energy to glucose then oxygen is absorbed in the lungs and circulate the blood through out the body by red blood cells.
Hence, we get glucose from food source.
To know more about cellular respiration, visit the below link:
https://brainly.com/question/2809259
1. Scientists create both scientific theories and scientific laws as they make observations and conduct experiments about the natural world. Which of the following statements most accurately compares the difference between scientific theories and scientific laws?
a) Scientific laws are based on evidence, while scientific theories are not.
b) Scientific theories involve only biology, while laws involve all types of science.
c) Scientific theories involve mathematical equations, while scientific laws are based on observations.
d) Scientific theories are ideas that explain natural events, while scientific laws more reliably predict natural events
Answer:
D
Explanation:
While scientific laws more accurately forecast natural events, scientific theories are beliefs that explain natural happenings. So, the correct option is D.
What is the difference between scientific laws and scientific theories?Scientific laws are explanations for why certain occurrences occur or explanations of the phenomenon occurring itself. The outcomes or the causes of such phenomena are not explained. By stating a link verbally or mathematically, it only clarifies the situation and makes the underlying "science" simpler to comprehend.
On the other hand, scientific theories are those that make an effort to define or clarify why a phenomenon occurs. Its foundation is observation. Before drawing a conclusion, there is still a process of learning or discovery. It is a conceptual framework for explaining and projecting new information.
Thus, the correct option is D.
Learn more about Scientific theories, here:
brainly.com/question/2375277
#SPJ3
PLEASE HELP ASAP
Volcanoes erupt as a result of
A) Two continental plates converging
B) One oceanic plate converging with one continental plate
C) Two tectonic plates transforming
Answer:
B.) One oceanic plate converging with one continental plate.
HOPE THIS HELPS!
Answer:
C: Two tectonic plates transforming
How many grams of HCl are needed to form 34.5 grams of Cl2?
Answer:
Expof HCl are required to produce 7.50 moles of ZnCl2? 6. Copper ... When 9.34 g of zinc react with excess hydrochloric acid how many grams of zinc chloride will.lanation: