Answer:
144 g of phosphorus contain 4.65 moles.
Explanation:
Given data:
Mass of phosphorus = 144 g
Number of moles = ?
Solution:
Formula:
Number of moles = mass/ molar mass
Molar mass of phosphorus is 31 g/mol
Now we will put the values in formula.
Number of moles = 144 g/ 31 g/mol
Number of moles = 4.65 mol
Thus, 144 g of phosphorus contain 4.65 moles.
What do organs combine to form? organ systems cells tissues organisms
Answer:
the answer is {organisms}
Answer:
organisms
Explanation: I took the test
Cold-winter survival experts do not recommend eating snow for hydration. One reason for this is the energy it takes to increase temperature of the snow, melt it, and then increase the temperature of the resulting water to body temperature. Calculate the total amount of heat to convert 2.000 kg of snow at -15.00 0C to liquid water at 38.00 0C.
POTENTIALLY HELPFUL INFORMATION:
The heat of fusion for water is 1.44 kcal/mol.
The specific heat capacity of solid water is 0.488 cal/g0C.
The specific heat capacity of liquid water is 1.00 cal/g0C.
The freezing point of water is 00C (also known as melting point).
Answer:
The total amount of heat is 250.64 kcal.
Explanation:
Given that,
Total amount of heat = 2.000 kg
Temperature of snow = -15.00°C
Temperature of water = 38.00°C
Heat of fusion of water = 1.44 kcal/mol
Specific heat of solid water = 0.488 cal/g°C
Specific heat of liquid = 1.00 cal/g°C
We need to calculate the heat required to bring temperature -15°C to 0°C snow
Using formula of heat
[tex]Q_{1}=mc_{p}\Delta T[/tex]
Put the value into the formula
[tex]Q_{1}=2000\times0.488\times(0+15)[/tex]
[tex]Q_{1}=14640\ cal[/tex]
[tex]Q_{1}=14.640\ kcal[/tex]
We need to calculate the heat required to convert 0°C snow into 0°C water
Using formula of heat
[tex]Q_{2}=ml[/tex]
Put the value into the formula
[tex]Q_{2}=\dfrac{2000}{18}\times1.44[/tex]
[tex]Q_{2}=160\ kcal[/tex]
We need to calculate heat required to increases temperature of water from 0°C to 38°C
Using formula of heat
[tex]Q_{3}=mc_{p}\Delta T[/tex]
Put the value into the formula
[tex]Q_{3}=2000\times1.00\times(38-0)[/tex]
[tex]Q_{3}=76000\ cal[/tex]
[tex]Q_{3}=76\ kcal[/tex]
We need to calculate the total heat
Using all heat amount
[tex]Q=Q_{1}+Q_{2}+Q_{3}[/tex]
Put the value into the formula
[tex]Q=14.640+160+76[/tex]
[tex]Q=250.64\ kcal[/tex]
Hence, The total amount of heat is 250.64 kcal.
How could the continents have gotten so far apart and how long did it take for this to happen
Which organ produces the female hormone estrogen?
A. Hypothalamus
B. Ovary
C. Pancreas
D. Testicle
Answer:
b-ovaries
Explanation:
Answer:
ovaries
Explanation:
i just know trust me tell me if its wrong
If 298 mL of 0.575 M CuCl2 is diluted into 750 mL, what is the concentration of new solution?
Answer:
The answer is 0.228 MExplanation:
To find the concentration of new solution we use the formula
[tex]C_1V_1 = C_2V_2[/tex]
where
C1 is the concentration of the stock solution
V1 is the volume is the volume of the stock solution
C_2 is the concentration of the diluted solution
V2 is the volume of the diluted solution
Since we are finding the the concentration of new solution
[tex]C_2 = \frac{C_1V_1}{V_2} \\[/tex]
From the question
C1 = 0.575 M
V1 = 298 mL
V2 = 750 mL
We have
[tex]C_2 = \frac{0.575 \times 298}{750} \\ = 0.228466666...[/tex]
We have the final answer as
0.228 MHope this helps you
Suppose you mix Na2SO4 and KCl solutions according to the given equation.
Na2SO4 (aq) + 2 KCl(aq) + 2 NaCl(aq) + K2SO4 (aq)
What evidence of a reaction do you expect to see?
Select one:
A precipitate should form.
A gas should form.
Water should form.
Ο Ο
No reaction should occur.
Answer:
No reaction should occur
Explanation:
Water cannnot be made from the components
Nothing will be released as a gas
Both products are soluible in water therefore will not form a precipitate.
If I mix a solution of Na2SO4 and KCl, no reaction should occur.
Whether or not, a reaction occurs when two substances are mixed depends on the respective positions of the substances in the electrochemical series.
Now, we are expecting the reaction; Na2SO4 (aq) + 2 KCl(aq) + 2 NaCl(aq) + K2SO4 (aq) to occur. The big question is, between sodium and potassium, which is higher in the electrochemical series?
A little look into the image attached shows that potassium is higher than sodium in the series so the reaction is possible.
However, the both products are aqueous, they are both soluble in water hence no visible reaction occurs.
Learn more: https://brainly.com/question/24058474
Calculate the number of grams of CuSO4 found in 3.29 mL of a 4.00 M CuSO4 solution. ______ grams CuSO4
Answer:
2.08g
Explanation:
Given parameters:
Volume of CuSO₄ = 3.29mL
Molarity = 4M
Unknown:
Mass of CuSO₄ = ?
Solution:
Let us find the number of moles from the given parameters first;
Number of moles = molarity x volume
1000mL = 1L
Express the volume of the given CuSO₄ in L = 3.29 x 10⁻³L
Number of moles = 4 x 3.29 x 10⁻³ = 0.013mol
So;
Mass of CuSO₄ = number of moles x molar mass
Molar mass of CuSO₄ = 63.6 + 32 + 4(16) = 159.6g/mol
Mass of CuSO₄ = 0.013mol x 159.6g/mol
Mass of CuSO₄ = 2.08g
What is the density if the mass is 25 g and the volume is 114 mL?
Answer:
0.219 g/mL.
Explanation:
From the question given above, the following data were obtained:
Mass = 25 g
Volume = 114 mL
Density =.....?
Density of a substance is simply defined as the mass of the substance per unit volume of the substance. Mathematically, it is expressed as:
Density = mass /volume
With the above formula, we can obtain the density of the substance given in the question above as follow:
Mass = 25 g
Volume = 114 mL
Density =.....?
Density = mass /volume
Density = 25/114
Density = 0.219 g/mL
Therefore, the density of the substance is 0.219 g/mL
Is a venus fly trap non-living?
What allows a liquid to take the form of the container it is in?
A.
strong intermolecular forces
B.
low temperature
C.
weak intermolecular forces
D.
low kinetic energy
Answer:
It's probably C
The forces between liquid particles are weaker than the forces between solid particles. This means that liquid particles are further apart and can move about more easily. Since the particles can move, the liquid can flow and take the shape of its container
Sorry if the answer is wrong!!!!!!
A scientist is studying two types of worms. Worm X has DNA identical to its parent. Worm Y has a combination of DNA from two parents. The scientist determines that one of the worms has a survival advantage over the other worm. Which statement correctly summarizes this conclusion? Worm X reproduces asexually, which gives it genetic variation. Worm Y reproduces sexually, which gives it genetic variation. Worm Y reproduces asexually, which gives it more DNA. Worm X reproduces sexually, which gives it more DNA.
Answer:
2. Worm Y reproduces sexually, which gives it genetic variation.
Answer:
B Worm Y reproduces sexually, which gives it genetic variation.
Explanation:
hope you all have a good day
7. Which of the following units would be MOST appropriate for measuring
the volume of a small can of soda? *
1 point
A. Liters
B. Milliliters
C. Grams
D. Kilograms
Use the metric ruler to answer questions 8 and 9.
Answer:
im pretty sure the answer is b
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HOPE IT HELPS
PLEASE MARK ME BRAINLIEST ☺️
A compound has the following composition by mass:
32% carbon, 6.7% hydrogen, 42.6% oxygen and 18.7% nitrogen
What is the empirical formula of the compound?
Answer:
i cry when im alone
Explanation:
How can the total energy of an open system be changed? Enter your answer in the space provided.
yes they can be changed becasue they are expose to the environment
That's why it's improtant to have a calorimeter so the energy and heat are contained
The total energy of an open system be changed if:
There is an exchange between matter and energyAccording to the First Law of Thermodynamics, energy cannot be created or destroyed, it can only change form.
An open system is a system that has an interaction with its environment where matter or energy can be added or removed from the environment.
As a result of this, the total energy of an open system can be changed if there is an exchange between matter and energy and they remain constant.
Therefore, the correct answer is an exchange has to take place for the total energy in an open system to be changed.
Read more here:
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What is the mass of 6.2x 1022 molecules of carbon monoxide?
Answer:
Mass = 2.8 g
Explanation:
Given data:
Number of molecules of CO = 6.2×10²²
Mass of CO = ?
Solution:
We will use Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.
The number 6.022 × 10²³ is called Avogadro number.
For example,
18 g of water = 1 mole = 6.022 × 10²³ molecules of water
For given 6.2×10²² molecules of CO mass will be,
1 mole = 6.022 × 10²³ molecules of CO
6.2×10²² molecule × 1 mole/ 6.022 × 10²³ molecules of CO
0.1 mol
Mass of CO:
Mass = number of moles × molar mass
Mass = 0.1 mol × 28 g/mol
Mass = 2.8 g
5) Which of these are intensive properties?
a substance has a volume of 5.4 mL
a substance has a mass of 1.25 g
a substance has a density of 4.13 g/cm3
a substance has a melting point of 40°C
a substance is very malleable (it can be hammered into a shape)
6) Which of these are extensive properties?
a substance has a melting point of 40°C
a substance is very malleable (it can be hammered into a shape)
a substance has a volume of 5.4 mL
a substance has a mass of 1.25 g
a substance has a density of 4.13 g/cm3
Answer:
For number 5 it is the 2nd one some stants has a mass of 1.25 g And the 2nd 1 number 6It is the 1st 1A subject has a melting point of 40
Which of the following is a common sign that a chemical change has occurred?
Where can you find most of Earth's liquid freshwater?
Answer:
Where can you find most of Earth's liquid freshwater?
Explanation:
Over 68 percent of the fresh water on Earth is found in icecaps and glaciers, and just over 30 percent is found in ground water. Only about 0.3 percent of our fresh water is found in the surface water of lakes, rivers, and swamps.
Hope that helped, i also have snap if you need me.
Over 68 per cent of the fresh water on Earth is found in icecaps and glaciers, and just over 30 per cent is found in groundwater. Only about 0.3 per cent of our freshwater is found in the surface water of lakes, and rivers.
What is the per cent of the water on this earth?The Earth is a watery place. About 71 per cent of the Earth's surface is water-covered, and the oceans hold about 96.5 per cent of all Earth's water.
The majority of Earth’s fresh water is stored in underground aquifers.
Aquifers are layers of sedimentary formations such as sandstone and fractured hard rocks where water after infiltration from soil reaches and fill the interstitial spaces.
Aquifers are huge in size in basins and contain a huge amount of underground water of fresh quality.
So, over 68 per cent of the freshwater is present on Earth.
Learn more about the freshwater here:
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The table lists some compounds found in foods and their formulas.
Based on this information, which of these statements is NOT true?
CLEAR
Answer:
A
Explanation:
the number of molecule won't be twice as fructose has 12 hydrogen molecules and lactose has 22 hydrogen molecules
From the given statements, the statement saying that the number of atoms in Lactose is twice the number of atoms in Fructose is not correct. Thus option A is correct.
The given molecules in the list are Glutamine, Lactose, fructose, and Sorbitol.
The number of atoms in the following compounds is:
Glutamine = 20 atomsLactose = 45 atomsFructose = 24 atomsSorbitol = 26 atoms.Statement A says that the number of atoms in Lactose is twice the number of atoms in Fructose. The twice atoms of Fructose are 48 atoms. The number of atoms of lactose is 45.
Thus statement A is incorrect. Thus option A is correct.
For more about the atoms in a molecule, refer to the link:
https://brainly.com/question/25617532
Marcy tests a solution with a strip of blue litmus paper. The paper turns red. The solution is _____.
acidic
basic
neutral
How many lead (Pb) atoms are in a 5.32 g sample of pure lead?
Answer:
1.55×10²² molecules.
Explanation:
We'll begin by calculating the number of mole in 5.32 g of pure lead (Pb). This can be obtained as follow:
Mass of Pb = 5.32 g
Molar mass of Pb = 207 g/mol
Mole of Pb =?
Mole = mass /molar mass
Mole of Pb = 5.32/207
Mole of Pb = 0.0257 mole
Finally, we shall determine the number of molecules in 0.0257 mole of Pb. This can be obtained as follow:
From Avogadro's hypothesis,
I mole of Pb contains 6.02×10²³ molecules.
Therefore, 0.0257 mole will contain = 0.0257 × 6.02×10²³ = 1.55×10²² molecules.
Therefore, 5.32 g of pure lead (Pb) contains 1.55×10²² molecules.
what istope of an atom if it has 29 protons and 36 neutrons?
Answer:
Copper Atoms
Explanation:
All copper atoms have atomic number 29: all their nuclei contain 29 protons. But they also contain uncharged particles called neutrons. In natural copper, the atoms are of two kinds. One has 29 protons and 34 neutrons in the nucleus; the other has 29 protons and 36 neutrons
PLEASE HELP!!!!!
What happens to the transfer of thermal energy when thermal equilibrium is reached?
Answer:
During the process of reaching thermal equilibrium heat is transferred between the object. heat is always transferred from the object at the higher temperature to the object with lower temperature. For a gas, the heat transfer is related to a change in temperature.
A testable explanation of or answer to a scientific question that is based on prior knowledge or research is a(n)
Answer:
the answer is HYPOTHESIS your welcome
Explanation:
What is the density (g / mL) of a substance that has a mass of 8.11 g and, when placed into a graduated cylinder, causes the water level to rise from 25.26 mL to 44.72 mL?
Answer:
The answer is 0.42 g/mLExplanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\[/tex]
From the question
mass = 8.11 g
volume = final volume of water - initial volume of water
volume = 44.72 - 25.26 = 19.46 mL
We have
[tex]density = \frac{8.11}{19.46} \\ = 0.416752312...[/tex]
We have the final answer as
0.42 g/mLHope this helps you
Which of the statements below about buoyancy is true?
A.if the buoyant force is greater than the force of gravity,the object will sink
B.buoyancy is a force that acts on objects that are placed in a fluid
C.all objects that experience the force of buoyancy float
D.buoyancy pushes objects down in the same direction as gravity
(answer asap plz I will give brainliest to who helps me )
Answer:
it's A. if the force of gravity is greater than the buoyant force, the object will sink.
Explanation:
just took the quiz on a p e x
Ionic crystals have high boiling points because:
A. They do not have high boiling points.
B. breaking ionic bonds requires a large amount of energy.
C. the structure has a large surface area to absorb heat quickly.
D. the positive and negative charges prevent them from absorbing heat quickly.
The answer would be B.
Which pair has the stronger ionic bond:
- MgCl2 vs. NaCl2
- NaCl vs. LiCl
What is the enthalpy of reaction for the decomposition of calcium carbonate?
CaCO3(s) Right arrow. CaO(s) + CO2(g)
Answer:
Explanation:
You will need to look up the Standard Heats of Formation* for each substance and apply Hess's Law Equation.
ΔH⁰(rxn) = ∑ΔH⁰(Products) - ∑ΔH⁰(Reactants)
*Std Heats of Formation can be found in the appendix of most college chem texts.
For this problem:
Given CaCO₃(s) => CaO(s) + CO₂(g)
∑ΔH⁰: -635.1 Kj/mole -393.5Kj/mole -1206.9
ΔH⁰(rxn) = [(-393.5 Kj/mole) + (-393.5Kj/mole)] - (-1206.9Kj/mole)
= (-635.1 -393.5 + 1206.9) Kj/mole
= +178.3 Kj/mole
Answer:
656.3 kJ
This reaction is endothermic
Explanation:
edge 2020
16.4 A cylinder of water contains oxygen in solution. The cross- sectional area of the cylinder is 2 cm2 and the length of the cylin- der is 5 cm. At one end of the cylinder the concentration of oxygern is maintained at 0.2 mol m-3, this concentration falls linearly to 0.05 mol m-3 at the other end of the cylinder. The diffusion con- stant of oxygen in water is 8 × 10-10 m2 s-1. How many moles of oxygen pass down this cylinder every second? What mass of oxy- gen passes down the cylinder each second?
Answer:
A) oxygen moles/sec = 48 * 10 ^-14 mol/sec
B) mass of oxygen = 1536*10^-14 grams
Explanation:
cross sectional area of cylinder = 2cm^2 = 2 * 10^-4 m^2
length of cylinder = 5 cm = 0.05 m
concentration at one end = 0.2 mol m^-3
concentration falls linearly at other end = 0.05 mol m^-3
Diffusion constant of oxygen = 8 * 10^-10 m^2 s^-1
A ) Number of moles of oxygen passing every second
N = A * D * [tex]\frac{dc}{dt}[/tex] ------- ( 1 )
A = area , D = diffusion constant, [tex]\frac{dc}{dt}[/tex] = rate of change of diffusion
dc /dt = ( 0.2 - 0.05 ) / 0.05 = 3 mol m^-4
back to the equation
N = ( 2 * 10^-4 ) * ( 8 * 10^-10 ) * ( 3 ) = 48 * 10 ^-14 mol/sec
B) Mass of oxygen passing down the cylinder each second
This can be obtained by converting : 48 * 10^-14 moles to grams
1 mole of oxygen = 32 grams of oxygen
therefore : 48 * 10^-14 moles of oxygen = ( 32 * (48*10^-14) = 1536*10^-14 grams