Question 3 0
A student has a lg sample of each of the following compounds: NaCl, Br, and KCL. Which of the following lists the samples in order of increasing number of moles in the sample?
Answers
Answer:
Option D. KBr < KCl < NaCl
Explanation:
We'll begin by calculating the number of mole of each sample.
This can be obtained as follow:
For NaCl:
Mass = 1 g
Molar mass of NaCl = 23 + 35.5 = 58.5 g/mol
Mole of NaCl =?
Mole = mass /Molar mass
Mole of NaCl = 1/58.5
Mole of NaCl = 0.0171 mole
For Kbr:
Mass = 1 g
Molar mass of KBr = 39 + 80 = 119 g/mol
Mole of KBr =?
Mole = mass /Molar mass
Mole of KBr = 1/119
Mole of KBr = 0.0084 mole
For KCl:
Mass = 1 g
Molar mass of KCl = 39 + 35.5 = 74.5 g/mol
Mole of KCl =?
Mole = mass /Molar mass
Mole of KCl = 1/74.5
Mole of KCl = 0.0134 mole
Summary
Sample >>>>>>>> Number of mole
NaCl >>>>>>>>>> 0.0171
KBr >>>>>>>>>>> 0.0084
KCl >>>>>>>>>>> 0.0134
Arranging the number of mole of the sampl in increasing order, we have:
KBr < KCl < NaCl
Related Questions
What is the average yearly rate of change of carbon-14 during the first 5000 years?
Answers
Answer:
The average yearly rate of change of carbon-14 during the first 5000 years = 0.0004538 grams per year
Explanation:
Given that the mass of the carbon 14 at the start = 5 gram
At the end of 5,000 years we will have;
[tex]A = A_0 \times e^{-\lambda \times t}[/tex]
Where
A = The amount of carbon 14 left
A₀ = The starting amount of carbon 14
e = Constant = 2.71828
[tex]T_{1/2}[/tex] = The half life
[tex]\lambda = 0.693/T_{1/2}[/tex]
t = The time elapsed = 5000 years
λ = 0.693/[tex]T_{1/2}[/tex] = 0.693/5730 = 0.0001209424
Therefore;
A = 5 × e^(-0.0001209424×5000) = 2.7312 grams
Therefore, the amount of carbon 14 decayed in the 5000 years is the difference in mass between the starting amount and the amount left
The amount of carbon 14 decayed = 5 - 2.7312 = 2.2688 grams
The average yearly rate of change of carbon-14 during the first 5000 years is therefore;
2.2688 grams/(5000 years) = 0.0004538 grams per year
The average yearly rate of change of carbon-14 during the first 5000 years = 0.0004538 grams per year.
Does riding a bike with larger tires help you go faster even if you pedal at the same rate A:if the person moves faster, then the person is riding a bike with larger tires B: if a person rides a bike with larger tires ,then the person with move faster than on a bike with smaller tires
Answers
Answer:
Yes, bikes with larger tires help you go faster.
B: if a person rides a bike with larger tires ,then the person with move faster than on a bike with smaller tires
Explanation:
Bikes with larger wheels cover more distances in one revolution, when compared to bikes with a much smaller wheel, if the wheels are turning at the same revolution per minutes. Although more effort is put into turning a big wheel, when compared to that for a smaller wheel, but it will go faster if you can keep it spinning at the same rate as a small one.
. Name something chemistry related you are interested in or interested in learning about.
Answers
Answer: How The World Works
Explanation: Our world is made out of atoms, molecules and ions. Their behavior determines the properties of the substances we encounter in our daily lives: their structure, color, smell, and the way they interact with each other.
Which of the following is a compound?
Select the correct answer below:
Water
Sodium
Chlorine
Oxygen
Answers
water
explanation:
water consists one oxygen atoms and two hidrogen of atom.
compound: have two or more atom
Hope this helps :)
A neutral atom has an equal number of positive and negative charges. If a neutral fluorine atom has 9 protons and 10 neutrons, how many electrons will it have?
Answers
Answer:
9 electrons.
Explanation:
Number of electrons = number of protons
= 9.
A shiny chunk of metal is found to have a mass of 37.28g. The metal is dropped into a graduated cylinder which contains 20.0 mL of water. The volume of the cylinder rises to 34.0 mL. Determine the density of the metal. What might the metal be made of?
Answers
Answer: The density of the material is 2.66 g/mL and it is likely this is made of Aluminum
Explanation:
The first step to know the material of the chunk of metal is to calculate its density. The general formula for density is P (density) = [tex]\frac{m (mass)}{ v (volume)}[/tex]. Moreover, in this case, it is known the mass is 37.28 g, but the volume is not directly provided. However, we know the water in the graduated cylinder had a volume of 20.0 mL and this increased to 34.0 mL when the chunk of metal is added, this means the volume of the metal is 14 mL (34.0 mL - 20.0 mL = 14 mL). Now let's calculate the density:
[tex]P =[/tex] [tex]\frac{37.28g}{14.0mL}[/tex]
[tex]P = 2.66 g/mL[/tex]
This means the density of this metal is 2.66 g/mL, which can be rounded as 2. 7 g/mL, and according to the chart, this is the density of aluminum. Therefore, this material of this chunk is aluminum.
What period is the atom in?
What group is the atom in?
What is the name of this atom?
What other atom would have similar properties
to the atom?
Would this atom be malleable or brittle?
Answers
It is in group 17
It is a chlorine atom because it has 17 electrons which means the atomic number is 17
The label on a soft drink bottle gives the volume in two units: 2.0 L and 67.6 fl oz. Use this information to derive a conversion factor between the English and metric units. How many significant figures can you justify in your conversion factor?
Answers
Answer:
Explanation:
The significant figures are determined by 2.0. It only has 2 places, so the answer to the last question is 2.
The English unit is 67.6 oz
The metric unit is 2 L
So there are 67.6 fl oz / 2 L = 33.8 fl oz / L
In other words 1 liter has 33.8 fl oz
But you only have 2 sig digs so the answer is actually 34 fl oz/L
Calculate the cell potential, Ecell, of a concentration cell containing a 0.1 M solution of Zn2 and a 1.0 M solution of Zn2
Answers
Answer:
The cell potential is 0.0296V
Explanation:
Please see the attachment below
Sulphur dioxide and oxygen reacts to form sulphur trioxide. The equilibrium mixture contain 5.0 × 10−2 M SO3, 3.0 × 10−3 M SO2 and 3.5 × 10−3 M O2. Calculate equilibrium constant for reaction?
Answers
Answer:
Keq = 79365
Explanation:
Based on the reaction of sulphur dioxide, SO2, with O2, to produce SO3:
2SO2 + O2 ⇄ 2SO3
The equilibrium constant of reaction (Defined as the ratio of concentrations of products over reactants powered to the coefficient of each reactant). For the reaction:
Keq = [SO3]² / [SO2]² [O2]
Replacing with concentrations of the problem:
Keq = [5.0x10⁻²]² / [3.0x10⁻³]² [3.5x10⁻³]
Keq = 79365How many bonds does argon group viii form
A. 0
B. 3
Answers
Answer:
option A is correct
Explanation:
argon belongs to noble gas which doesnt form any type of chemical bond
The number of bonds that will argon group will form is zero, as it already have octet configuration.
What is noble gas?Nobles gases are the most stable gases present in the periodic table and electronic configuration of valence shell of these gases are always complete or stable i.e. 2 or 8.
Argon is a noble gas, whose atomic number is 18 and valence shell has 8 electrons. As we know that atoms will take participate in bond fomation to get the stable state and fulfilled valency, so argon will not form any bond as it is already in stable state.
Hence argon will form zero bonds.
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Where is the mass of an atom found? Explain.
Answers
Explanation:
Over 99.9% percent of an atom's mass resides in the nucleus. The protons and neutrons in the center of the atom are about 2000 times heavier than the electrons orbiting around it.
Because the electrons are so light by comparison,they represent only a tiny fraction of a percent of the atom's total weight.
Hope this answer helps you!
A sample of iron shot is added to a graduated cylinder containing 47.5 mL of water. The water level rises to the 51.1 mL mark. The density of iron is 7.87 g/mL. From this information, calculate the mass of the sample. *
Answers
Answer:
The mass of iron shot is 28.3 grams.
Explanation:
Given that the initial volume of water is 47.5 mL and final volume of water containing iron shot is 51.1mL. First, you have to find the volume of iron shot by subtracting :
[tex]47.5 + iron \: shot = 51.1[/tex]
[tex]iron \: shot = 51.1 - 47.5[/tex]
[tex]iron \: shot = 3.6ml[/tex]
Next, we have to apply density formula, D = mass/volume :
[tex]d = \frac{m}{v} [/tex]
[tex]let \: d = 7.87,v = 3.6[/tex]
[tex]7.87 = \frac{m}{3.6} [/tex]
[tex]m = 7.87 \times 3.6[/tex]
[tex]m = 28.3g \: (3sf)[/tex]
Matthew has been collecting quarters in a jar. He has 176 quarters. What is the value of the coins in his jar?
Answers
Answer:
The correct answer is : 44 dollars.
Explanation:
A quarter is one fourth of a dollar that is the reason it is known as quarter. A quarter is 25 cents or 0.25 dollar in value. If Matthew has 176 quarters in his jar than the value of the total coins would be:
1 quarter = 0.25 dollar
1 quarter = 1/4 dollar.
4 quarter = 1 dollar
then, 176 / 4 = x dollar
= 44 dollar
Thus, The correct answer is : 44 dollars.
Wind erosion
ER
O removes the fertile B horizon of soil
o can be reduced by cutting down trees
O happens slowly in dry climates
en in de
is both destructive and constructive
Answers
Answer:
removes the fertile B horizon of soil
Explanation:
Wind erosion has the capacity to remove the fertile B horizon of the soil.
The term wind erosion generally refers to the capacity of high-magnitude wind to cause damages to the terrestrial environment. Soils can get their topmost layers removed by a strong wind if there are no barriers such as vegetation to break the speed of the wind.
The topmost layers in most cases consist of humus and the fertile minerals from parent materials. When the topmost layer is lost, the soil becomes unproductive for agriculture.
Explain which is the better coolant: water or methanol?
Answers
Answer:
Water
Explanation:
Because it has a higher specific heat capacity.
Water is a better coolant than methanol due to its high specific heat capacity.
The specific heat is the amount of heat per unit mass required to raise the temperature by one degree Celsius.
It is a measure of how much energy it takes to raise the temperature of a substance. It is the amount of heat necessary to raise one mass unit of that substance by one temperature unit.
Methanol effective in preventing the coolant from freezing, its low boiling point and low specific heat capacity led to considerably less cooling than water alone. Also, the concentration of methanol would tend to be reduced over time due to its greater tendency to evaporate than the water with which it was mixed.
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HELP!! ILL MARK BRAINLIEST!! Why do shows about ghosts often feature mostly nighttime scenes? This is the only time of day ghosts are present. This time of day produces more dramatic footage. This is the time of day when it is easiest to see ghosts. This is the only time spiritual energy can be measured.
Answers
We sense "ghosts" that aren't there because of our heightened state of anxiety, our incapacity to discern nighttime stimuli effectively, our belief that bad entities should favor the dark, and our relative lack of nighttime experience.
The correct option is (B) This time of day produces more dramatic footage.
In ghost stories, ghosts frequently manifest at night for a variety of reasons:
Because our inclination to fear the dark is inherent. In the daytime, we can see nearby predators; at night, we cannot. We are more exposed.Because it's difficult for humans to see in the dark, it's simpler to imagine things that aren't actually there. Our brain is capable of putting together several pieces of data to construct an experience that didn't actually take place. For instance, at darkness, we can hear things but not see them.Because nightfall is nasty and dangerous, it makes sense that wicked things would emerge at this time of day. It seems sense that spirits would prefer the night over the day, at least on the surface.We have a lot of experience not seeing ghosts during the day and far less experience seeing ghosts at night. That instance, if someone were to say, "X tends to happen around 4pm," you would respond, "no, it doesn't," but if they said, "X tends to happen at 4am," you may be a little unsure. There are moments of the night when you aren't awake all that often.Learn more about the Anxiety with the help of the given link:
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A stream flows at a rate of 10.4 liters per hour. Convert this rate to cubic meters per day.
Answers
Answer:0.2496m³/day
Explanation:
A lab group was measuring the mass of an object. They recorded the following masses for the same object: 12.13 g, 12.12 g, 12.13 g, and 12.11 g. The actual mass of the object was 17.13 g. Which of the following best describes the lab groups results? The results were both accurate and precise. The results were accurate but not precise. The results were precise but not accurate. The results lacked both precision and accuracy.
Answers
Answer:
Precise, but not accurate
Explanation:
First, let’s define accuracy and precision.
⇒Accuracy: how close you are to the actual value
⇒Precision: how close the measurements are to each other.
Let’s examine the data given:
12.13 g, 12.12 g, 12.13 g, and 12.11 g
Each number is or is very close to 12.12 (within 0.1)
The actual mass of the object is 17.13 grams. Each measurement is about 5 grams away from the actual mass.
Since the measurements are very close to each other, but quite far from the true value, we can say the results are precise, but not accurate.
what is Ionization Energy?
Answers
Answer:
Ionization energy is a measure of the difficulty involved in removing an electron from an atom or ion or the tendency of an atom or ion to surrender an electron.
Explanation:
Answer:
This is the energy required to remove a valence electron from an atom of the element to form an ion.Generally,there is a tendency for ionization energies to increase across a period and decrease down a group....
Which part of an atom is mostly empty space? nucleus proton cloud electron cloud neutron
Answers
Answer:
its C
Explanation:
Cloud electron is a part of an atom is mostly empty space. Hence option D is correct.
What is atom?It is the smallest unit of matter that possess the properties of the chemical element. It can’t be an independently, they form ions and molecules they both are combine and form large numbers of matters.
Every solid, liquid, gas, and plasma are composed of neutral or ionized atoms.
Atoms are basically three types: Neutrons, protons and electrons. In atoms there are two regions:
The nucleus (with protons and neutrons)Positive chargeElectron clouds: Most of the volume of an atom.
The region where the electrons can be found (mostly empty space). Cloud electron is a part of an atom is mostly empty space. Hence option D is correct.
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10. This is a neutral atom. What is this element
Answers
Answer:
I guess carbon
Explanation:
The sodium atom loses an electron to form a sodium Ion (Na+). Which statement is correct with respect to its atomic radius?
O A. The sodium ion has a larger radius than the atom.
OB.
The sodium lon has a smaller radius than the atom.
OC.
The sodium ion and the sodium atom radil are the same size.
OD
The sodium ion has twice the radius of the sodium atom.
Answers
Answer:
sodium ion has smaller radius than a atom.
Explanation:
A chemistry student must write down in her lab notebook the concentration of a solution of sodium hydroxide. The concentration of a solution equals the mass of what's dissolved divided by the total volume of the solution. Here's how the student prepared the solution: The label on the graduated cylinder says: empty weight: She put some solid sodium hydroxide into the graduated cylinder and weighed it. With the sodium hydroxide added, the cylinder weighed . She added water to the graduated cylinder and dissolved the sodium hydroxide completely. Then she read the total volume of the solution from the markings on the graduated cylinder. The total volume of the solution was . What concentration should the student write down in her lab notebook? Be sure your answer has the correct number of significant digits.
Answers
Answer:
1.099 gmL¯¹ ≈ 1.1 gmL¯¹
Explanation:
From the question given above, the following were obtained:
Mass of empty cylinder = 9.5 g
Mass Cylinder + NaOH = 31.92 g
Volume of solution = 20.4 mL
Concentration of solution =?
Next, we shall determine the mass of sodium hydroxide, NaOH. This can be obtained as as illustrated below:
Mass of empty cylinder = 9.5 g
Mass Cylinder + NaOH = 31.92 g
Mass of NaOH =?
Mass of NaOH = (Mass Cylinder + NaOH) – (Mass of empty cylinder)
Mass of NaOH = 31.92 – 9.5
Mass of NaOH = 22.42 g
Finally, we shall determine concentration of the solution as follow:
Mass of NaOH = 22.42 g
Volume of solution = 20.4 mL
Concentration of solution =?
Concentration = mass /volume
Concentration of solution = 22.42 / 20.4
Concentration of solution = 1.099 gmL¯¹ ≈ 1.1 gmL¯¹
Therefore, the concentration of the solution is 1.1 gmL¯¹
What year did Canada switch to the metric system?
Answers
Answer:
1970
Explanation:
1970, Canada gradually began to convert from an imperial to a metric system of measurement
A. The pendulum would accelerate to the left
B. The pendulum would accelerate downward
C. The pendulum would accelerate to the right
D. The pendulum would accelerate upward
Answers
Answer:
The pendulum would accelerate to the left
Explanation:
hope this helps
1. What are the characteristics of scientific thinking and investigating? 2.Why is science literacy important? 3.What skills and tools do scientists use? 4.Why is the use of the inquiry process (or scientific method) a practical way to approach science? 5.Why are scientific theories modified, but seldom discarded? 6.How has science and technology influenced everyday life?
I WILL GIVE BRAINLIEST TO ANYONE WHO ANSWERS!!!!!!!!
Answers
Answer: kindly check explanation
Explanation:
Characteristics of scientific thinking and investivating:
1) Empiricism : Also called empirical evidence maybe classed as natural evidences used to butress or support a certain notion or fact usually attainable from experience or teaching.
11.) Rational : Rational thinking or attribute could simply be tagged as reasonable and do not negate laid down facts.
111.) Skepticism: This is very imperative in scientific research as it opens the way to further research enabling researchers to gather more evidences required to establish a strong argument.
2.) IMPORTANCE OF SCIENCE LITERACY
Science literacy simply empowers mankind. Nourishing researchers or literates with the knowledge of its natural environment and enabling them understand, explore and exploit resources in our environment.
3.) Skills and tools scientist need :
Skills :
1) Curiosity: The ability to frame and and ask questions is key to establishing a purpose for research. Asking the right questions is key in a scientific process.
11) Data gathering or collection: Obtaining the right data capable of proferring the essential solution to our research question is key to obtaining logical insight.
111) Communication: Once research is complete, it is essential that researchers possess the skills required in transmitting their conclusion in a way which is both simple, logical and sensible.
Tools include common laboratory equipments such as beaker, testube, measuring cylinders, microscope and so on.
4.) The scientific or inquiry method provides a stepwise, easy to understand and logical approach to problem solving, Hence, providing a lucid and evidence - based conclusion which is both practicable and reproducible.
5.) The main reason for the modification of scientific theories is that they are susceptible to further research or study. As a result of evolution and change in trend depending on various natural and environmental factors, modification may occur in the form of review without abrogating previously existing studies.
6.) Science and technology has enabled mankind to adjust and cope with the continuous evolutionary changes in our environment. Enabling us to use these findings to ease our everyday living standard.
In a survey that asked about alcohol use in high school students, which of
these is an important measure for controlling bias?
A. Developing a program to combat alcohol use
B. Getting a random sample from all grade levels
C. Asking the high school seniors
D. Asking students if they would like to participate
SEMA
Answers
Answer: B
Explanation: to have a control, and many samples to investigate and cover the differences and anseretics.
In a survey that asked about alcohol use in high school students , the important measure for controlling bias is "Getting a random sample from all grade levels".
What is alcohol?A chemical compound is found in alcoholic beverages like beer, wine, as well as liquor. Several medicines, mouthwashes, home items, as well as essential oils contain it.
In a survey that asked about alcohol use in high school students , the important measure for controlling bias is "Getting a random sample from all grade levels".
Therefore, the correct answer will be option (B).
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A 4.80-gram piece of magnesium displaces 2.76 mL of water when it is placed in a graduated cylinder. What is the density of magnesium?
Answers
Answer:
1.73913043g/mL
Explanation:
Density is how much a substance would weigh per 1 mL of the substance. So it is measured by dividing weight (g) by volume (mL).
4.80g/2.76mL = 1.73913043g/mL
at 100c the vapour pressure of a solution of 6.5g of solute in 100g of water is 732mm if kb is 0.52 k/m the boiling point of solution will be
Answers
Answer:101.105⁰c
Explanation: