the correct one is D
During recrystallization, why is it necessary to cool the solution slowly?
answer:
the reason is to ensure more solute is dissolving as it cools down. it is important to do it slowly because water will be sucked into buchner flask by a partial vaccum through the rubber tubing and be able to arrange molecules.
A mixture of hydrogen, nitrogen, and water vapor has a total pressure of 864 mmHg. The partial pressure of hydrogen is 220 mmHg and that of nitrogen is 410 mmHg. What is the partial pressure of water vapor?
Answer:
As per Dalton's law of Partial pressure,
The total pressure of a mixture of gases is equal to sum of partial pressure of individual components of the mixture.
So,P=P_H+P_N+P_WP=P
H
+P
N
+P
W
\implies 864\ mm=220\ mm+410\ mm+P_W\implies⟹864 mm=220 mm+410 mm+P
W
⟹ P_W=864-630=234P
W
=864−630=234 mm of Hg.
Explanation:
"The partial pressure of water vapor is 234 mm Hg."
What is partial pressure?
The force that a gas exerts is known as partial pressure. The total pressure of a mixture of gases is equal to the sum of their partial pressures.
Partial pressure can be calculated by using the formula: [tex]P_{Total} =P_{N} +P_{H} +P_{H}[/tex]
Puts the value of given data in above equation.
[tex]Px_{W} =864-410-220\\\\= 234 mm Hg[/tex]
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Atoms share one or more pairs of electrons.
Options:
Ionic Bond or Covalent Bond?
Answer:
covalent bonds
Explanation:
ionic transfer of e^- ions formed (charges)
ionic=non-metal+ metal
ex: F+Ca
covalent sharing e^- no true charges
covalent= non-metal+ non-metal
ex: F+P
( my notes)
If you were able to magnify a penny down to the atomic level, what two
observations could you make about the atoms?
The two observations you would make about the atoms are
They are made up largely of empty spaceTheir mass is concentrated at the center called a nucleusThese observations were made by Ernest Rutherford in his model of the atom established in 1911, when he performed his gold foil experiment and observed the scattering angle of the alpha particles which led him to conclude that the mass of the atom was concentrated at the center.
Also, that most of the alpha particles also went through the gold foil suggested that the atom was made up basically of empty space.
So,
The two observations you would make about the atoms are
They are made up largely of empty spaceTheir mass is concentrated at the center called a nucleusLearn more about the atom here:
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hello how to draw the electron dot structure of H2S and F2?
Explanation:
1. Attachment
Electron dot structure of H2S (hydrogen sulfide)
2. Attachment
Electron dot structure of F2 (Fluorine).
I need a catchphrase for the element Boron as a superhero describing its traits!
Atomic Number
Atomic Mass Number
Protons
Neutrons
Electrons
Charge
Element 1
6
12
A
6
6
B
Element 2
6
13
6
C
D
1+
Look at the above table.
How many neutrons should be at (C) Element 2
Question 5 options:
6
7
11
13
Answer: 7
Explanation:
protons + neutrons = atomic mass number
4. Explain error and how it can impact your results from an experiment
Random errors will shift each measurement from its true value by a random amount and in a random direction. These will affect reliability (since they're random) but may not affect the overall accuracy of a result.
Ammonium sulphate + __________________ potassium sulfate + ammonia + water
Please fill in the blank.
Answer:
Potassium Hydroxide Solution =
or
Potassium Hydroxide =
Since we know the products and one of the reactions, we can work backward to discover what the other reactant may be.
As it is in the question, we can map the reactants and product:
Reactants Product
Ammonium Ammonia
Sulfate Sulfate
________ Potassium
________ Water
Since the reaction will yield Potassium and water, the likely reactant is Potassium Hydroxide (KOH). This is because we know that Ammonium lost a Hydrogen atom that could combine with the Hydroxide radical to form water.
This becomes clear when we consider the net ionic equation:
Ammonium sulphate + Potassium Hydroxide → potassium sulfate + ammonia + water
if we write this a balanced chemical equation:
(NH₄)₂SO₄ + 2KOH → K₂SO₄ + 2NH₃ + 2H₂O
if we write the reaction as an ionic equation
2NH₄⁺ + SO₄⁻ + 2K⁺ + 2OH⁻ → 2K⁺ + SO₄⁻ + 2NH₃ + 2H₂O
if we remove the ions that appear on both the reactant and product side (spectator ions)
2NH₄⁺ + 2OH⁻ → + 2NH₃ + 2H₂OWhat words did the Pilgrims use to describe the new laws?
new and legal
just and equal
godly and fair
In the underlined section, what do the colonists promise to do?
“… and by virtue hereof to enact, constitute and frame such just and equal Laws, … as shall be thought most meet and convenient for the general good of the Colony, unto which we promise all due submission and obedience.”
—Mayflower Compact
Write down the names, physical properties, and inertness of NOBLE GASES ( group no. 8)
Note:
*Please don't copy from anywhere
*50 POINTS!!!!!!!!
Answer:
There's No Answer Im Sorry
Difference Between baking soda and baking powder
Answer:
Baking soda is sodium bicarbonate, which requires acid and a liquid to become activated and help baked goods rise. Conversely, baking powder includes sodium bicarbonate, as well as an acid. It only needs a liquid to become activated. Substituting one for the other is possible with careful adjustments. Baking soda is strong. In fact, it is about 3-4x stronger than baking powder. More baking soda in a recipe doesn't necessarily mean more lift.
Explanation:
Explanation:
baking soda contains one ingredient, sodium bicarbonate. however, baking powder contains sodium bicarbonate , monocalcium phosphate and either sodium acid prophetess or sodium aluminum sulfate
Convert 1.00 us gallon in kilometer (kL)
HELPPPP PLEASE WILLLL GIVE BRIANLIESTTTT
We can use the formula M₁V₁ = M₂V₂ the total volume of water that will yield 0.800 M HCl. We can then subtract that from the initial volume to get how much water needs to be added.
Since M₁V₁ = M₂V₂ (starting mole× starting volume = end mole × end volume)
⇒ (5 mol)(20 mL) = (0.80 mol) V₂
100 mol/mL = 0.8 mol × V₂
⇒ V₂ = 100 mol/mL ÷ 0.8 mol
= 125 m
Since we began with 20.0 mL of water,
water needed to add = 125 mL - 20 mL = 105 mL
Pleaseee helppp!!!!!
Answer:
it releases energy that is used for power
Explanation:
Answer: It releases energy that is used for power.
Explanation: https://www.investopedia.com/terms/h/hydrocarbon.asp
Which one please help
Answer:
density is mass more mass more density and same as volume
Block A is made of copper, which has a specific heat value of 0.385 J/g*C.
Block B is made of aluminum, which has a specific heat value of 0.900
J/g*C. Both blocks have a mass of 100 grams. If you are trying to heat the
blocks to a temperature of 200 C, which block will need to absorb more
energy?
o Block A (copper) because it has a lower specific heat value.
o Block B (aluminum) because it has a higher specific heat value.
o Block A (copper) because it has a higher specific heat value.
o Block B (aluminum) because it has a lower specific heat value.
Block B will need to absorb more energy as it has higher specific heat value.
What is specific heat?Specific heat is defined as the amount of heat required to raise the temperature of one gram of a substance by one degree Celsius rise. Units of specific heat are calories or joules per gram per degree Celsius.
Specific heat capacity varies with temperature often and is different for each state of matter. While the substance which undergoes phase transition then it's specific heat is technically infinite.
Specific heat of a gas is significantly higher when it is allowed to expand as it is heated .It may also be referred to as a ratio between the specific heat capacities of two substances at a given temperature.It is calculated by the formula ,Q=mcT
For copper, it is 100×0.385×473=18210.5 J
For aluminium ,it is 100×0.90×473=42570 J
As the specific heat of aluminium is higher it will absorb more energy.
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3. Which of the following are examples of chemical changes? Select all that apply.
-Water freezing
-Cookies baking
-Dry Ice subliming
-Wood burning
Answer:
wood burning and cookies baking
Explanation:
took the test <333
Answer:
Wood burning and cookies baking
Explanation:
When you cut an apple, what are the chemical changes and physical changes when cutting it?
Answer:
cutting of an apple is both physical and chemical change
because cutting a apple, the size and shape of the apple changes. it will be a chemical change because after cutting an apple, the color apple changes when left open
A field of many different species of wildflowers would be considered a(n) _____________.
a
organism
b
population
c
community
d
ecosystem
e
biome
f
biosphere
Answer:
That would be a community.
Explanation:
A field of many different species of wildflowers is considered to be a community.
What is community in biological terms?It is called biological community meaning an interacting group of various species sharing a common location.Factors which determine overall structure of community are number of species, abundance of each species,interaction among the species and community's ability to return to normal after a natural calamity.
Change of communities over a period of time is called as ecological succession.Each species in a community has its own characteristic niche . The niche includes all the interactions of the species with other members of the community.An ecosystem comprises of biological community together with its physical environment.
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What kind of feature results from the convergence of two oceanic plates?
Answer: When a convergent boundary occurs between two oceanic plates, one of those plates will subduct beneath the other. Normally the older plate will subduct because of its higher density. The subducting plate is heated as it is forced deeper into the mantle, and at a depth of about 100 miles (150 km) the plate begins to melt.
Explanation:
what type of mixture is formed when black iron filings and yellow sulfur powder black iron filing is formed
Homogeneous
Heterogeneous
Compound
Answer:
when you heat the blend, you form iron sulfide, a compound
Depending on the ratio, you could form Fe4S3 or fool's gold
Explanation:When iron filings and sulphur powder are mixed and heated they undergo a chemical reaction and form ferrous sulphide (FeS). It is a new substance which has properties entirely different from Fe and S. Therefore, heating of mixture of iron and sulphur powder is a chemical change forming a compoundf
Someone pls help me I will make you you brain
Answer:
i have no clue
Explanation:
umm cause i have no clue sorry lol but good luck
what is the empirical formula of a compound that contains only iron and oxygen and is 22.27% oxygen?
Answer:
A) FeO
Explanation:
Options:
A) FeO
B) FeO2
C) Fe2O
D) Fe7O2
The correct answer is A) FeO.
(Hope this helps can I pls have brainlist (crown)☺️)
The empirical formula of a compound that contains only iron and oxygen and is 22.27% oxygen is FeO. The correct option is A.
What is the empirical formula?The simplest whole number ratio of atoms in a chemical molecule is its empirical formula. The empirical formula is the chemical formula that gives the number of atoms of the chemical formula that is given in the chemical reaction.
For example, the C₆H₁₂O₆ is the formula of glucose. The simplest formula is CH₂O. This will be the simplest ratio of this compound. The first one, this C₆H₁₂O₆ is the molecular formula.
It only contains the element one quantity. The empirical formula that contains oxygen and iron will be FeO. The empirical formulas is calculated by dividing the simplest formula.
Thus, the correct option is A) FeO.
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The question is incomplete. Your most probably complete question is given below:
A) FeO
B) FeO2
C) Fe2O
D) Fe7O2
how does decreasing the temperature affect the volume of gas??
Answer: Well, when you decrease the temperature in a gas the volume will decrease as well as the pressure. Since, heating a gas or liquid increases the temperature/pressure. Therefore, it'd increase the volume but since the temperature is decreasing the volume of the gas does too.
Someone pls help me I will make you brain
ANSWER : I AND III
HOPE IT HELPED
hello
Describe the structure of solid potassium iodide.
Answer:
Potassium iodide is a metal-halide salt that has an ionic connection between the potassium cation (K+) and the iodide anion (I–). It is colorless to white and appears as cubical crystals, powder, or white granules. It has a salty, astringent flavor. This chemical is made from iodine and potassium hydroxide.
What will be the new pressure of a gas at 36.0 atm and 108 C if the temperature of the gas is increased to 441 C?
Answer
199 ATM
EXPLANATION
assume that the volume is constant. At higher temp the gas molecules move faster and the pressure goes up.
P=kT
CONVERT C TEMP TO K TEMP FOR GAS PROBLEMS!!!!!!
108C = 108 +273 = 381 K
441C = 441 + 273 = 714K
P=kT
108 =k x 381
K=108/381 = 0.279
AT THE HIGHER TEMP
P =0.279 X 714 =199ATM
What is the energy of a single photon with a wavelength of 750 nm.
Answer:
Refer to the attachment
What is the frequency of red light with a wavelength of 645 nm?
Answer:
4.64E14
Explanation:
First convert 645 nm to m = 6.4500E-7m. The equation for finding v with these values is the speed of light/wavelength. so 2.998E8/6.4500E-7m.
so your v or frequency would equal 4.64E14
Fun fact you know this is visible light because the visible light range is within the E14 range.