Answer:
55.9 g KCl.
Explanation:
Hello there!
In this case, according to the definition of molality for the 0.500-molar solution, we need to divide the moles of solute (potassium chloride) over the kilograms of solvent as shown below:
[tex]m=\frac{mol}{kilograms}[/tex]
Thus, solving for the moles of solute, we obtain:
[tex]mol=m*kilograms[/tex]
Since the density of water is 1 kg/L, we obtain the following moles:
[tex]mol=0.500mol/kg*1.50kg\\\\mol=0.75mol[/tex]
Next, since the molar mass of KCl is 74.5513 g/mol, the mass would be:
[tex]0.75mol*\frac{74.5513g}{1mol}\\\\55.9g \ KCl[/tex]
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Answer:
[tex]\Delta _{fus}H=205J/g=13.03kJ/mol[/tex]
Explanation:
Hello there!
In this case, since the heat of fusion is a property that allows us to calculate the heat involved during the change from solid to liquid (fusion) and is calculated as shown below:
[tex]Q=m*\Delta _{fus}H[/tex]
In such a way, given the heat involved during this process and the mass of copper, we calculate the heat of fusion as shown below:
[tex]\Delta _{fus}H=\frac{Q}{m}=\frac{41000J}{200.g}\\\\\Delta _{fus}H=205J/g[/tex]
Or in kJ/mol:
[tex]\Delta _{fus}H=205\frac{J}{gCu}*\frac{63.546 gCu}{1molCu}\\\\ \Delta _{fus}H=13026.93J/mol=13.03kJ/mol[/tex]
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A container containing 5.00 L of a gas is collected at 100 K and then allowed to expand to 20.0 L. What must the new temperature be in order to maintain the same pressure (as required by Charles' Law)?
Answer:
[tex]T_2=400K[/tex]
Explanation:
Hello there!
In this case, according to the given information for this question, it turns out possible for us to calculate the final temperature, after the expansion process, by using the well-known Charles' gas law:
[tex]\frac{T_2}{V_2}=\frac{T_1}{V_1}[/tex]
Thus, we solve for the final temperature to obtain:
[tex]T_2=\frac{T_1V_2}{V_1}[/tex]
And plug in the given values:
[tex]T_2=\frac{100K*20.0L}{5.00L}\\\\T_2=400K[/tex]
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A sample of carbon monoxide at 57 degrees Celsius and under 0.75 atm occupies 85.3 liters of space. What mass of carbon monoxide is present in the sample?
Write 6.3 x 10^2 in standard form.
O 0.063
O 630
O 63
O 63
Answer:
it will be 630
Explanation:
HOW MANY ELEMENTS ARE IN 3FE(OH)3
Answer:
Three
Explanation:
Iron
Oxygen
Hydrogen
There are four stages to the classical demographic transition model Pre-transitional Europe was characterized by high and
fluctuating mortality and a high birth rate. The transition model began to progress into and through stage 2 in the late 18th and early
19th century. All BUT ONE contributed to the decline in mortality.
S- -1]))
A)
Enacting measures to provide clean water supplies.
B)
Public health advances including quarantine of settlements undergoing
epidemics
The development of vaccines to prevent disease and antibiotics to treat
infection.
D)
Widespread acceptance of germ theory resulting in more hygienic
practices, including hand washing and sterilizing medical equipment and
infants' bottles.
When 100 identical steel balls are placed on a
triple beam balance, their mass is determined to
be 1,450 grams. The mass of a single steel ball
would be closest to
Explanation:
thank you for the points
8. In order to find molarity, you must know what two things? *
Answer: - The moles of solute present in the solution.
- The volume of solution (in liters) containing the solute.
Explanation:
How many grams of oxygen are required to burn 3.01 x 10^23 propane molecules?
differences between diamond and graphite
Answer:
dimond is stronger
Explanation:
Answer:
Graphite and Diamond are different because they have different structures. ... However each carbon atom in Diamond has 4 covalent bonds with other Carbons, making it extremely strong and hard. On the other hand, each carbon in graphite is bonded to three carbons, and therefore graphite is formed in layer
Also:
Each carbon atom in a diamond is linked to four other carbon atoms. Each carbon atom in graphite is linked to three other carbon atoms. Diamond is poor conductor of electricity due to the absence of free electrons. Graphite is good conductor of electricity due to the presence of free electrons in its structure.
Explanation:
Hope this helps
A certain mass of water was heated with 41,840 Joules, raising its temperature from 22.0°C to 28.5 °C. Find the
mass of the water.
Answer:
1.5 × 10³ g
Explanation:
Step 1: Given and required data
Transferred heat (Q): 41,840 JInitial temperature: 22.0 °CFinal temperature: 28.5 °CSpecific heat capacity of water (c): 4.184 J/g.°CStep 2: Calculate the temperature change
ΔT = 28.5°C - 22.0 °C = 6.5 °C
Step 3: Calculate the mass (m) of water
We will use the following expression.
Q = c × m × ΔT
m = Q / c × ΔT
m = 41,840 J / (4.184 J/g.°C) × 6.5 °C = 1.5 × 10³ g
1. What are the five symbiotic relationships?
2. What is mutualism? Explain mutualism with an example and a picture.
3. What is commensalism? Explain with an example and a picture.
4. What is predation? Explain with an example and a picture.
5. What is parasitism? Explain with an example and a picture.
6. What is competition? Explain with an example and a picture.
Write a CER paragraph (5- 8 complete sentences) answering the following prompt:
Why are symbiotic relationships important in an ecosystem?
Answer:
1) There are five main symbiotic relationships: mutualism, commensalism, predation, parasitism, and competition.
2) The term mutualism can be simply defined as a relationship in which both species are mutually benefited. This relationship can either be within the species or between the two different species. ... Here ants are the mutualist and acacia trees is the host. The acacia tree provides home and food for the ants.
3) Commensalism is a type of symbiotic relationship in which one species benefits, while the other species is neither harmed nor helped. The species that gains the benefit is called the commensal. ... An example is a golden jackal (the commensal) following a tiger (the host) to feed on leftovers from its kills.
4) Predation is the interaction between organisms in which one organism known as the predator kills another organism which is known as prey. ... Examples of predation are a lion eating deer or a snake eating rats. This results in the transfer of energy from the prey to the predator.
5) Parasitism is generally defined as a relationship between the two living species in which one organism is benefitted at the expense of the other. The organism that is benefitted is called the parasite, while the one that is harmed is called the host. A few examples of parasites are tapeworms, fleas, and barnacles.
6) Competition is a negative interaction that occurs among organisms whenever two or more organisms require the same limited resource. ... For example, animals require food (such as other organisms) and water, whereas plants require soil nutrients (for example, nitrogen), light, and water.
Symbiotic relationships are important because they are a major driving force of evolution. This networking and cooperation among species allows them to survive better than they would as individuals.
Cell membranes are selectively permeable. This means that A. only water can move freely across the cell membrane. B. any substance can move across the cell membrane, but chemical energy will always be required. C. some substances can move freely across the cell membrane, while others must be transported. D. no substances can move freely across the cell membrane.
Answer:
C. some substances can move freely across the cell membrane, while others must be transported.
Explanation:
how many molecules in 400g of acetic acid
Answer:chemical formula of acetic acid is or
so, molecular mass of acetic acid = 2 × atomic mass of C + 4 × atomic mass of H + 2 × atomic mass of O
= 2 × 12 + 4 × 1 + 2 × 16
= 24 + 4 + 32
= 60g/mol
given mass of acetic acid = 22g
so, no of moles of acetic acid = given mass/molecular mass
= 22/60 ≈ 0.367
so, number of moles of acetic acid is 0.367mol
number of molecules in 0.367 mol of acetic acid = 6.022 × 10²³ × 0.367
= 2.21 × 10²³
Explanation:
Which type of molecule is shown below?
O A. Alkene
O B. Cyclic alkane
O C. Alkane
O D. Alkyne
Answer:
A. Alkene
Explanation:
Alkenes are a class of hydrocarbons characterized by the possession of a carbon to carbon double bond (=) in their structure. This means that C=C is the functional group of alkenes. Alkenes have the general formula; CnH2n.
Based on the structure in the attached image, the structure can be identified to be an ALKENE because it possess a C=C functional group. Specifically, the IUPAC name of the structure is 1,2- dimethyl ethene.
what does it mean to count atoms
When you count atoms, remember to multiply the coefficient number and the subscript number to find the number of atoms of that element. Examples: ▪ 2H2O. Number of atoms Number of molecules = 2. H-4.
How many sulphur atoms are there in 0.125 moles of sulphur
Explanation:
There are 6.022x1023 molecules in 1 mole of SO3 (Avogadro's number) so in 0.25 moles, there are (0.25)(6.022x1023) molecules in the 0.25 moles of SO3. or 1.506x1023 molecules per 0.25 moles of SO3.
There is one atom of sulfur in each molecule of SO3. So there are 1.506x1023 atoms of sulfur in 0.25 moles of SO3.
According to the concept of Avogadro's number there are 0.7525 ×10²³ atoms of sulfur in 0.125 moles of sulfur.
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 atoms of sulfur are calculated as, Avogadro's number×number of moles, that is,6.022×10²³ ×0.125=0.75275×10²³ atoms
Therefore, there are 0.75275×10²³ atoms in 0.125 moles of sulfur.
Learn more about Avogadro's number,here:
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The initial concentration of a solution of NaOH is 5.0 M. What volume of the concentrated stock solution is needed to make 200 mL of .02 M solution? (YOU MUST INCLUDE UNITS IN YOUR ANSWER) *
Answer:
0.8 mL
Explanation:
Use the formula M1V1 = M2V2.
Plug the values in.
5(V1) = 0.02(200)
5V1 = 4
V1 = 0.8 mL
Hope this is right, correct me if I'm wrong!
Charge q is 1 unit of distance away from the source charge S. Charge p is two times further away. The force exerted
between S and q is the force exerted between S and p.
O 1/2
O 2 times
O 1/4
O 4 times
Answer:1/4
Explanation:
what is the mass spectrom
Answer:
Here's your Answer
Explanation:
the mass spectrum is the graphical representation of the ion abundance versus the mass to charge of the ions separated in mass spectrometer
What determines the brightness of a light wave?
Answer: The brightness of light is related to intensity or the amount of light an object emits or reflects. Brightness depends on light wave amplitude, the height of light waves. Brightness is also somewhat influenced by wavelength.
Explanation:
A neutralization reaction is taking place between solutions of phosphoric acid and calcium
hydroxide. For each mole of calcium phosphate produced by this reaction, how many moles
of water are produced?
a. 2
c. 4
b. 3
d. 6
Answer:
A
Explanation:
hope this help sweetie <$
A balloon is inflated to a volume of 8.0 L on a day when the atmospheric pressure is 1.013 bar . The next day, a storm front arrives, and the atmospheric pressure drops to 0.968 bar . Assuming the temperature remains constant, what is the new volume of the balloon, in liters
Answer:
[tex]V_2=8.4L[/tex]
Explanation:
Hello there!
In this case, according to the definition of the Boyle's law, which describes de pressure-volume behavior as an inversely proportional relationship, it is possible for us to write:
[tex]P_1V_1=P_2V_2[/tex]
Thus, since we are given the initial pressure and temperature, and the final pressure, we are able to calculate the final volume as shown below:
[tex]baV_2=\frac{P_1V_1}{P_2}\\\\V_2=\frac{8.0L*1.013bar}{ 0.968bar}\\\\V_2=8.4L[/tex]
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An experimental measurement was taken of 10.4mL and the actual measurement was 9.7mL. What is the percent error?
Answer:
13%
Explanation:
Which one is a transferable type of energy?
A. Potential
B. Heat
C. Internal
D. Stored energy
E. Kinetic
Answer:
E. Kinetic
Explanation:
Kinetic Energy. Energy is transferred from one object to another when a reaction takes place. Energy comes in many forms and can be transferred from one object to another as heat, light, or motion, to name a few. For the blue ball to move to the position of the green ball, energy must be given to the blue ball.
Brainlyest please
An object becomes positively charged when it loses electrons. O loses protons. O gains electrons. O gains neutrons.
an object becomes positively charged when it LOSES ELECTRONS.
* protons are positive, so losing protons means that it would be negatively charged.
* gaining electrons would make it more negatively charged.
* gaining neutrons changes nothing because neutrons are neutral.
How can heat energy transform from mechanical energy?
A)Burning
B)Friction
C)Light
D)Flames
Answer:
A
Explanation:
brainliest pls
. What is global warming? What can people do to reduce global warming?
Answer:
definition- the long-term heating of Earth's climate system observed since the pre-industrial period (between 1850 and 1900) due to human activities, primarily fossil fuel burning, which increases heat-trapping greenhouse gas levels in Earth's atmosphere.
Power your home with renewable energy, Invest in energy-efficient appliances, and Reduce water waste etc.
Answer:
Global warming is an effect on Earth, caused when too much carbon dioxide is present in the air. Carbon dioxide is a green house gas and partially restricts radiation from going back to into space, preventing the Earth from becoming too cold.
However, too much carbon dioxide has the effect of warming the Earth more than normal as it traps more heat on Earth. Thus, the greenhouse effect is enhanced- in short, global warming means that the Earth is much more warmer than normal.
The temperature on Earth has increased by 0.5 °C in the last 100 years. Although this doesn't seem like much, but a small increase can cause a big change. Global warming causes ice sheets to melt and causes sea levels to rise. Due to this, costal flooding frequently happens. In drier seasons, the heat is also more intense becuase of global warming.
Global warming can be reduced by burning less fossil fuels and using solar and wind power instead. Using more public transport could also help reduce carbon dioxide present in the atmosphere, as less vehicles will be releasing carbon dioxide. Reducing the amount of deforestation will greatly help reduce global warming, because trees absorb carbon dioxide from the atmosphere, and through the process of carbon dioxide, they change it into oxygen.
The balmer thermometer uses the atomic transitions of what element to measure the temperature of stars?
A. Helium
B. Gamma rays
C. Hydrogen
D. Nitrogen
E. Water
Fu/kushima Daiichi nuclear disaster (Research)
1. When and where did this accident happen?
2. Describe the incident and cause.
3. Who was responsible?
4. How many people were injured or died? (short term and long term)
5. How could the accident have been prevented?
6. What chemicals were involved?
7. What are the chemicals physical and chemical properties? (refer to their safety data sheets)
8. What are the chemicals uses, what products are they used in?
9. What health problems did the accident cause?
10. Relate details from the accident to chemistry topics we have covered so far
11. Compare and contrast the safety protocols used at the time of the accident to current safety practices for the same chemical.
Answer:
I don't know
Explanation:
give me you research