Answer:
A heating curve graphically represents the phase transitions that a substance undergoes as heat is added to it. The plateaus on the curve mark the phase changes. The temperature remains constant during these phase transitions.
How many molecules are in 2.0 grams of
Na2SO4?
Answer:
450 grams of Na2SO4
Explanation:
hope that helps
At what temperature does water freeze in Celsius
Answer:
32°c
Explanation:
Because in F it would be 0°f
Density equals _____.
volume divided by mass
mass divided by volume
weight divided by area
weight divided by volume
What is the definition of an Isomer?
Answer:
Each of two or more compounds with the same formula but a different arrangement of atoms in the molecule and different properties.
Explanation:
An organic chemist is planning to extract 1.00 g of an organic compound dissolved in 200.0 mL of water into a diethyl ether solvent. The partition coefficient for this system is 9.5, favoring the diethyl ether solvent. What percentage of the organic compound remains in the aqueous solvent if you perform three successive extractions with 50.0 mL of diethyl ether for each extraction?(a) 29.63% (b) 2.60% (c) 0.00169%
Answer:
(b) 2.60%
Explanation:
Partition coefficient of the organic compound in ether is:
9.5 = Concentration in ether / Concentration in water
In the first extraction, X is the amount of organic compound extracted:
9.5 = X/50mL / (1-X)/200mL
9.5 = 200X / (50-50X)
475 - 475X = 200X
475 = 675X
X = 0.7037g are extracted.
Remains = 1g - 0.7037g = 0.2963g
Second extraction:
9.5 = X/50mL / (0.2963-X)/200mL
9.5 = 200X / (14.815-50X)
140.74 - 475X = 200X
140.74 = 675X
X = 0.2085g are extracted.
Remains = 0.2963g - 0.2085g = 0.0878g
Third extraction:
9.5 = X/50mL / (0.0878g-X)/200mL
9.5 = 200X / (4.3899-50X)
41.70 - 475X = 200X
41.70 = 675X
X = 0.2085g are extracted.
Remains = 0.0878g - 0.0618g = 0.026g remains
Percentage: 0.026g / 1g * 100 =
(b) 2.60%Most of the mass in an atom is found in the...?
Calculate the density of the rock if its mass is 360 g.
Answer:
12.0 g/mL
Explanation:
From the question given above, the following data were obtained:
Mass of Rock = 360 g
Volume of water = 150 mL
Volume of water + Rock = 180 mL
Density of Rock =?
Next, we shall determine the volume of the rock. This can be obtained as follow:
Volume of water = 150 mL
Volume of water + Rock = 180 mL
Volume of Rock =?
Volume of Rock = (Volume of water + Rock) – (Volume of water)
Volume of Rock = 180 – 150
Volume of Rock = 30 mL
Finally, we shall determine the density of the rock as illustrated below:
Mass of Rock = 360 g
Volume of Rock = 30 mL
Density of Rock =?
Density = mass /volume
Density of Rock = 360 / 30
Density of Rock = 12.0 g/mL
Thus, the density of the rock is 12.0 g/mL
Why is the following electron configuration not possible?
1-9-1
Answer: because its noy
Explanation:
A mixture of Xe, Kr and Ar has a total pressure of 6.70 atm. What is the mole fraction of Kr if the partial pressure of Xe is 1.60 atm and that of Ar is 2.80 atm.
Answer:
0.343
Explanation:
Step 1: Given data
Total pressure of the gaseous mixture (P): 6.70 atmPartial pressure of Xe (pXe): 1.60 atmPartial pressure of Ar (pAr): 2.80 atmStep 2: Calculate the partial pressure of Kr
The total pressure of the mixture is equal to the sum of the partial pressures of the individual gases.
P = pXe + pAr + pKr
pKr = P - pXe - pAr
pKr = 6.70 atm - 1.60 atm - 2.80 atm
pKr = 2.30 atm
Step 3: Calculate the mole fraction of Kr
We will use the following expression.
X(Kr) = pKr/P
X(Kr) = 2.30 atm/6.70 atm
X(Kr) = 0.343
Considering the Dalton's partial pressure, the mole fraction of Kr is 0.34.
The pressure exerted by a particular gas in a mixture is known as its partial pressure.
So, Dalton's law states that the total pressure of a gas mixture is equal to the sum of the pressures that each gas would exert if it were alone:
[tex]P_{T} =P_{1} +P_{2} +...+P_{n}[/tex] where n is the number of gases.
This relationship is due to the assumption that there are no attractive forces between the gases.
Dalton's partial pressure law can also be expressed in terms of the mole fraction of the gas in the mixture.
So in a mixture of two or more gases, the partial pressure of gas A can be expressed as:
[tex]P_{A} =x_{A} P_{T}[/tex]
In this case, you know:
Total pressure= 6.70 atm. Partial pressure of Xe is 1.60 atm. Partial pressure of Ar is 2.80 atm.So, replacing in the Dalton's partial pressure law:
[tex]P_{T} =P_{Xe} +P_{Ar} +P_{Kr}[/tex]
6.70 atm= 1.60 atm + 2.80 atm + [tex]P_{Kr}[/tex]
6.70 atm- 1.60 atm- 2.80 atm= [tex]P_{Kr}[/tex]
2.30 atm=[tex]P_{Kr}[/tex]
Then: [tex]P_{Kr} =x_{Kr} P_{T}[/tex]
2.30 atm= [tex]x_{Kr}[/tex] 6.70 atm
[tex]x_{Kr}[/tex] =2.30 atm ÷6.70 atm
[tex]x_{Kr}[/tex] = 0.34
In summary, the mole fraction of Kr is 0.34.
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brainly.com/question/14239096?referrer=searchResults brainly.com/question/25181467?referrer=searchResults brainly.com/question/14119417Which statement is incorrect?
Acids produce H+ ions when ionized.
B. Bases produce OH^ lons when lonized.
C. Bases are found in the pH range of 1-7 on the pH
scale.
Distilled water has a neutral pH of 7.0.
Answer:
C. Bases are found in the pH range of 1-7 on the pH scale.
Explanation:
Acids are less than 7 on the pH scale, so 1-7. Bases are more than 7 on the pH scale, so 7-14. That's why C is incorrect, hope this helps!
Select the correct answer. The perimeter of a rectangle is 42 inches. If the width of the rectangle is 6 inches, what is the length? A. 12 inches B. 15 inches C. 21 inches D. 40 inches
Answer:
15
I hope this helps
How does one determine a percent composition from an empirical
formula?
A. Divide the atomic mass of the element by its subscript and
multiply by 100%
O B. Divide the mass of the compound by the atomic mass of
the element and multiply by 100%
O C. Divide the subscript of the element by the mass of the
element and multiply by 100%
O D. Divide the total mass of each element by the mass of the
compound and multiply by 100%
The way one determines a percent composition from an empirical formula is to divide the total mass of each element by the mass of the compound and multiply by 100%.
What is empirical formula?Empirical formula is a notation that indicates the ratios of the various elements present in a compound, without regard to the actual numbers.
The empirical formula of a compound is the simplest ratio that can exist between the constituent elements of a compound.
However, the percent composition of a compound can be determined by dividing the total mass of each element by the mass of the compound and multiply by 100%.
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A 1.50 mol sample of He occupies a volume of 2.50 L at a pressure of 14.7 atm. What will be the pressure of a 1.50 mol sample of H2 gas under the same conditions? a 7.33atm b 14.7atm c 29.4 atm d 1.00 atm
Answer:
el n = M/m. El nº de moles = m/M
Se utiliza la fórmula general de los gases: P*V = n*R*T
P = 760/760 = 1 atm
V = 0,5 L
n = masa de Cl2/masa molecular = masa de Cl2/70
R = 0,082
T = 273 + 20º C = 293 K
1*0,5 = masa de Cl2/70*0,082*293
0,5/0,082*293 = masa de Cl2/70
0,0208 = masa de Cl2/70
masa de Cl2 = 70*0,0208 = 1,46 g
epilacion:
Suerte
what is the atomic number of oxygen
Answer: The atomic number of oxygen is "O" .
Explanation:
Because Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as well as with other compounds.
How many grams of N2 are required to react with 2.30 moles of Mg in the following process? 3 Mg + N2 → Mg3N2? (Mg = 24.3 g/mol, N = 14.0 g/mol)
Answer: 10.73 g
Explanation:
2.3 mol Mg * (1 mol N2 / 3 mol Mg) * (14 g Mg / 1 mol g) = 10.73
Write two sentences explaining how the illustration and student observations support the cell theory?
Answer:
The classical cell theory was proposed by Theodor Schwann in 1839. There are three parts to this theory.
Explanation:
what step of the scientific method do we decide whether our hypothesis was correct or not
Convert 98.5 Pa into mm Hg. (133.32 Pa = 1.00 mm Hg)
Describe the role of chloroplasts in photosynthesis. (ASAP)
Answer:
Chloroplasts absorb sunlight and use it in conjunction with water and carbon dioxide gas to produce food for the plant. Chloroplasts capture light energy from the sun to produce the free energy stored in ATP and NADPH through a process called photosynthesis.
Explanation:
Which shows three human body parts in order from the simplest level of organization to the most complex?
red blood cell → nervous system → bone tissue
nervous system → bone tissue → red blood cell
red blood cell → heart tissue → circulatory system
bone tissue → red blood cell → nervous system
Answer:
red blood cell → heart tissue → circulatory system
Explanation:
The levels of organization from the simplest level of organization to the most complex is cell, tissue, organ, organ, organ system, and organism. Red blood cells are cells, heart tissue is tissue in the heart and the circulatory system is an organ system that ensures blood, oxygen, and nutrients are flowing through the body.
Red blood cell → heart tissue → circulatory system shows the three human body parts in order from the simplest level of organization to the most complex.
What is heart?Heart is a muscular organ which is present in most of the animals , it is responsible for pumping blood via the blood vessels to the entire body.The blood which is pumped carries oxygen and nutrients along with it.Along with it on it's way back to heart it carries carbon dioxide to the lungs.
Heart has an approximate size of a closed fist and is present between the lungs in the middle compartment of the chest. It is divided in to for chambers , the upper chambers called atria and lower ones called ventricles.
The wall of the heart is made up of three layers : epicardium,myocardium and endocardium. It pumps blood with a rhythm which is determined by a group of cells which are called the pacemaker cells present in the sinoatrial node.
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When a sample of liquid is heated, its thermal energy _______.
Answer:
Entropy.
Explanation:
I really hope this is right! sorry if its wrong
When a sample of liquid is heated, its thermal energy: increases.
Thermal energy can be defined as the energy possessed by an object due to the movement of its particles.
Basically, the temperature of an object or system is highly dependent on thermal energy.
Hence, temperature is directly proportional to thermal energy.
Additionally, as the temperature of an object increases due to the application of heat, the thermal energy of the object increases.
In conclusion, thermal energy increases when a sample of liquid is heated.
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100. g of ice at 0 is added to 300.0 g of water at 60C. Assuming no transfer of heat to
the surroundings, what is the temperature of the liquid water after all the ice has
melted?
The final temperature of the liquid water after all the ice has melted is equal to 25°C.
What is the specific heat capacity?The specific heat capacity can be described as the quantity of heat needed to raise the temperature in one unit (1kg) of substance by one-degree Celcius.
The formula to show the relationship between the specific heat capacity and heat absorbed or lost is:
Q = mCΔT
Given, the amount of ice, m = 100g
The amount of water, M = 300g
The specific heat capacity of the water, C = 1 cal /g°C
The heat of fusion of ice, C = 80 cal/g
Heat given by water = Heat taken by ice + Heat taken by water formed from ice
300 × 1 ×(60 - T) = 100 × 80 + 100 × 1 ×T
18000 - 300 T = 8000 + 100 T
400 T = 10000
T = 25°C
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PLS HELP!!!!
How do the products of chemical reactions compare to their reactants?
The products usually have more atoms than the reactants.
The products usually weigh more than the reactants.
The products often have completely different properties than the reactants.
The products are usually more toxic than the reactants.
How do the products of chemical reactions compare to their reactants?
Answer:
The products often have completely different properties than the reactants.
The correct answer to the question is: The products often have completely different properties than the reactants.
In a chemical reaction, the reactants and products of the reaction have different properties because during the reaction, bonds were broken and new bonds were formed which generate a new substance called the product.
However, chemical equations must be balanced in order to conform to the law of conservation of matter which states that matter can neither be created nor destroyed during a chemical reaction but can be transferred from one form to the other.
For example, the reaction of Hydrogen gas (H₂) and oxygen gas (O₂) to produce water (H₂O)
2H₂(g) + O₂(g) —> 2H₂O(l)From the equation, we can see that the reactants are gases but the product is a liquid which has a different properties from the gaseous reactants.
Therefore, the correct answer to the question is: The products often have completely different properties than the reactants.
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Please help!!! I will give five stars and points for correct answer with an explanation.
What do the blue and red lines indicate?
A cold front is moving to the north and west before a warm front moves through.
A cold front is moving to the south and east before a warm front moves through.
A warm front is moving to the north and east before a cold front moves through.
A warm front is moving to the south and west before a cold front moves through.
Picture is attached.
Answer:
A cold front is moving to the north and west before a warm front moves through.
Explanation:
The blue line indicated a cold front and the red line indicates a warm front. Both lines are moving up (north) and to the left (west) on the globe. Key words are north and west, which indicates the direction of which the fronts are moving even if it is unclear of which front is before the other.
How many moles of O2 are required to react completely with 5.00 moles of C4H10?
A) 10.0
B) 20.0
C) 26.5
D) 32.5
Answer:
32.5
Explanation:
2C⁴H¹⁰ needs 13 O²
5 C⁴H¹⁰ needs (13/2 × 5) O² = 32.5 O²
The answer is D, 32.5
(I took the test)
1. The state of Georgia has seen their water table become lower. What does this mean?
The amount of groundwater is increasing.
Their groundwater is being recharged by rain.
The amount of groundwater is decreasing.
Their groundwater is flowing to confined aquifers.
Answer:
The amount of groundwater is decreasing.
Explanation:
In an ecosystem like the state of Georgia where the water table has become lower it means that the amount of groundwater in the ecosystem is decreasing.
What is an ecosystem?Ecosystem is defined as a system which consists of all living organisms and the physical components with which the living beings interact. The abiotic and biotic components are linked to each other through nutrient cycles and flow of energy.
Energy enters the system through the process of photosynthesis .Animals play an important role in transfer of energy as they feed on each other.As a result of this transfer of matter and energy takes place through the system .Living organisms also influence the quantity of biomass present.By decomposition of dead plants and animals by microbes nutrients are released back in to the soil.
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4)
Fluorine and element Z have similar chemical properties. Element Z could have an electron
configuration of
A)
2-2
B)
2-8-1
C)
2-8-8
D)
2-8-18-7
Answer:
D) 2.8.18.7
Explanation:
because it has 7 valence electron that occupied by shells
List what you are thankful for! (It's Thanksgiving! Answer if you bake! Or if you like cakes pies cookies and treats!!! )
Answer:
I do not bake but my mom is a professional baker.
Explanation:
A roof over my head and a warm home.
Plenty of drinkable water.
I don't have to go hungry.
I can enjoy the small and free pleasures of life.
Access to the internet.
My friends and family.
My health.
The kindness of people I have never met before.
What is the charge on an atom after it gains two electrons during the formation of a bond?
One positive charge
Two positive charges
Two negative charges
One negative charge
Answer:
Two Negative Charges
Explanation:
C. Two negative charges
If an atom has an equal number of protons and electrons, its net charge is 0. If it gains an extra electron, it becomes negatively charged and is known as an anion. If it loses an electron, it becomes positively charged and is known as a cation.Given condition: An atom gains two electrons during the formation of a bond.
As we know gaining an electron results in a negative charge and here two electrons being gained.
Therefore, the charge on it after gaining two electrons will be two negative charges.
Thus, the correct option is option C.
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5.75 x 1021 molecules of oxygen is the equivalent of how many
moles?
765.75
................................