The question is incomplete, the complete question is;
A certain liquid X has a normal freezing point of 5.40 °C and a freezing point depression constant K=3.05 ?kg mol solution made of 46.1g of alanine (C3H,NO2) dissolved in 750. g of i. Round your answer to 3 significant digits.
Answer:
3.3 °C
Explanation:
If ∆T= K m I
Where;
∆T = freezing point depression
K = freezing point constant
m= morality of solution
i= Van't Hoff factor
Number of moles of solute = 46.1 g/89.09 g/mol = 0.52 moles
Molality of solution = 0.52 moles /750 ×10-3Kg
= 0.69 m
∆T= 3.05 × 0.69 × 1
∆T= 2.10 °C
Freezing point of solution the solution = freezing point of pure solvent - freezing point depression
= 5.40°C - 2.10 °C
= 3.3 °C
A chemist must prepare 900.0 mL of potassium hydroxide solution with a pH of 12.20 at 25°C.
He will do this in three steps:
• Fill a 900.0 mL volumetric flask about halfway with distilled water.
• Weigh out a small amount of solid potassium hydroxide and add it to the flask.
. Fill the flask to the mark with distilled water.
Calculate the mass of potassium hydroxide that the chemist must weigh out in the second step. Round your answer to 2 significant digits and put your answer in grams (g).
Answer:
0.80 g
Explanation:
First we calculate the required pOH from the given pH value:
pOH = 14 - pHpOH = 14 - 12.20 = 1.80Then we calculate the required concentration of OH⁻, using the pOH:
pOH = -log[OH⁻][OH⁻] = [tex]10^{-1.80}[/tex] = 0.0158 MAs the concentration of OH⁻ species is the sames as the concentration of KOH, we need to prepare 900 mL of a 0.0158 M KOH solution:
We calculate how many KOH moles are required, using the concentration and volume:
Converting 900 mL ⇒ 900 / 1000 = 0.900 Lmoles = 0.0158 M * 0.900 L = 0.01422 molFinally we convert 0.01422 moles of KOH to grams, using its molar mass:
0.01422 mol * 56 g/mol = 0.80 gUse the following key to classify each of the elements below in its elemental form:
A. Discrete atoms ...
B. Molecules ...
C. Metallic lattice
D. Extended, three-dimensional network
1. Argon
2. Bromine
3. Nitrogen
4. Fluorine
Answer:
Discrete atoms
Argon
Molecules
Bromine
Nitrogen
Fluorine
Explanation:
The existence of substances in the elemental form depends on the nature of the substance.
Argon is a noble gas hence it seldom participates in chemical combination therefore it exists as discrete molecules in elemental form.
Bromine, fluorine and nitrogen all exist as diatomic gases because they combine readily with each other to form elemental molecules. An elemental molecule is a molecule composed of the atoms of the same element.
What type of reaction is rusting?
O A. Decomposition
O B. Double-displacement
O C. Single-displacement
OD. Oxidation-reduction
If a solid line represents a covalent bond and a dotted line represents intermolecular attraction, which of the choices shows a hydrogen bond?
1. H−H
2. H4C⋯H−F
3. H3N⋯H−O−H
4. H2O⋯H−CH3
Answer:
3
Explanation:
Hydrogen bonding occurs between molecules in which hydrogen is bonded to a highly electronegative atom such as nitrogen, oxygen, chlorine, etc.
In option 3, the two compounds are H3N and H2O. In both molecules, hydrogen is directly attached to highly electro negative atoms(nitrogen and oxygen respectively). Hence, it is only in option 3 that we observe hydrogen bonding.
Its Acutally A Because if you use the type he used its not even the question
Explination
Im RIght
How many moles of aluminum oxide are produced according to the reaction below given that you start with 40.0 grams of Al and 19.0 grams of O2?
Reaction: 4Al + 3O2 --> 2Al2O3
A. 0.185
B. 0.741
C. 5.00
D. 0.396
From the stoichiometry of the reaction, 0.74 moles of aluminium oxide is produced.
The equation of the reaction is;
4Al + 3O2 --> 2Al2O3
Number of moles of Al = 40.0/27 g/mol = 1.48 moles
Number of moles of O2 = 19.0 g/32 g/mol = 0.59 moles
Now;
4 mols of Al reacts with 3 moles of O2
1.48 moles of Al reacts with 1.48 moles × 3 moles/4 mols
= 1.11 moles
We can see that O2 is the reactant in excess.
Hence;
4 moles of Al produces 2 moles of aluminium oxide
1.48 moles of Al produces 1.48 moles × 2 moles/4 moles = 0.74 moles of aluminium oxide
Learn more about stoichiometry: https://brainly.com/question/9743981
A molecule of composition is replicated in a solution containing unlabeled (not radioactive) GTP, CTP, and TTP plus adenine nucleoside triphosphate with all its phosphorus atoms in the form of the radioactive isotope 32P. Will both daughter molecules be radioactive
Answer:
Please find the complete question in the attached file.
Explanation:
It would only be radioactive if the DNA molecule that employed the poly-T rand as templates. Its other molecule of the daughter would not have been radioactive as it did not need dATP for its replication. While each strand of the second molecule includes t, simultaneous reproduction dATP from both daughter molecules is needed so that each of those is radioactive.
2. Which of the following equations represents a neutralization reaction?
a. H2CO3 + H2O + CO2
b. 2H2O2 → 2H2O + O2
c. Ba(NO3)2 + K2CO3 →
BaCO3 + 2KNO3
d. HNO3 + NaOH → NaNO3 + H2O
Answer:
d. HNO3 + NaOH → NaNO3 + H2O
Explanation:
Hello there!
In this case, according to the given chemical reactions, it turns out necessary for us to recall the definition of neutralization reaction as those whereby an acid reacts with a base, that is why a, b and c are not within the aforementioned description.
In such a way, we infer the reaction is d. HNO3 + NaOH → NaNO3 + H2O since HNO3 is the acid and NaOH the base.
Regards!
Which of the following is key to generating a bell curve?
Why is blood considered a suspension?
Answer:
Because platelets and other things are "suspended" in the plasma.
Explanation:
When blood is put into a centrifuge it separates into its separate components (eg: Red blood cells, plasma, White blood cells, platelets, etc)
As a result of the particles in a gas being in constant motion, gas has a _______.
variable volume
variable Pressure
variable Shape
variable mass
Answer:
i think it's variable pressure
if not soo advance sorry :)
How long does it take for water to boil?
Answer:
around 5-10 minutes it may take but the actual answer is when the temperature of water reaches 100°Celsius
Answer:
How Long Does It Take to Boil Water? To boil 1 liter of water (4 cups), it takes about 8 to 10 minutes in a pot on the stove with high heat and the lid on. 1 liter of water boils in an electric kettle in about 4 to 5 minutes. 1 liter of water boils in a microwave in about 3 to 4 minutes
have a great day
#brainlestReactants which do not continue to completion are called reactants
When 20 grams of KCIO3, is dissolved in 100 grams of water, the solution can be
described as.............if the solubility equals 53.3g/100g H20.
a. Saturated
c. supersaturated
b. unsaturated
d. concentrated
Answer:
b. unsaturated .
Explanation:
Hello there!
In this case, according to the given information, it turns out necessary for us to bear to mind the definition of each type of solution:
- Supersaturated solution: comprises a large amount of solute at a temperature at which it will be able to crystalize upon standing.
- Unsaturated solution: is a solution in which a solvent is able to dissolve any more solute at a given temperature.
- Saturated solution can be defined as a solution in which a solvent is not capable of dissolving any more solute at a given temperature.
In such a way, since 20 grams of the solute are less than the solubility, we infer this is b. unsaturated, as 33.3 grams of solute can be further added to the 100 grams of water.
Regards!
How is a bacterium cell different from a human cell?
Answer:
Human cells are eukaryotic which means they are more complicated, bacteria cells are prokaryotic which means they are simpler
Explanation:
Hope this helps
how many moles of H2o are equivelant to 97.3g h2o
Answer:
Number of mole in H2O = 5.4 moles
Explanation:
Given:
Mass of H2O = 97.3 gram
Find:
Number of mole in H2O
Computation:
We know that molar mass of H2O = 18 g/mole
So,
Number of mole = Given Mass / Molar mass
Number of mole in H2O = Mass of H2O / Molar mass of H2O
Number of mole in H2O = 97.3 / 18
Number of mole in H2O = 5.4055
Number of mole in H2O = 5.4 moles
Iodine-131 is administered orally in the form of NaI(aq) as a treatment for thyroid cancer. The half-life of iodine-131 is 8.04 days. If you begin with 34.7 mg of this isotope, what mass remains after 8.52 days have passed
Answer:
16.6 mg
Explanation:
Step 1: Calculate the rate constant (k) for Iodine-131 decay
We know the half-life is t1/2 = 8.04 day. We can calculate the rate constant using the following expression.
k = ln2 / t1/2 = ln2 / 8.04 day = 0.0862 day⁻¹
Step 2: Calculate the mass of iodine after 8.52 days
Iodine-131 decays following first-order kinetics. Given the initial mass (I₀ = 34.7 mg) and the time elapsed (t = 8.52 day), we can calculate the mass of iodine-131 using the following expression.
ln I = ln I₀ - k × t
ln I = ln 34.7 - 0.0862 day⁻¹ × 8.52 day
I = 16.6 mg
The maximum number of moles of compound E that may be formed in the following reaction is: ЗА + 5B + c 个 2E Initial moles: n(A)=0.20 n(B)=0.30 n(C)=0.10
Answer:
E=1.1
Explanation:
let's consider moles of E is X
3(0.20)+5(0.30)+0.10 =2X
2.2=2X
x=1.1
What is the mass of NaCl required to make 150 grams of a 12% solution of NaCl in water? (5 points)
a
13 grams
b
18 grams
c
22 grams
d
32 grams
Answer:
18 grams
Explanation:
Mass of solution = 150 g
Percent concentration = 12%
Percent concentration = mass of solute/mass of solution × 100
Let the mass of solute be x
12= x/150 × 100
12= 100x/150
12 × 150 =100x
x= 12 × 150/100
x = 18 g
Answer:
18
Explanation:
Mass of solution = 150 g
Percent concentration = 12%
Percent concentration = mass of solute/mass of solution × 100
Let the mass of solute be x
12= x/150 × 100
12= 100x/150
12 × 150 =100x
x= 12 × 150/100
x = 18 g
help me plsssssssss.... im timed
Answer:
a
Explanation:
a
Answer:
B. Isotopes of the element.
Explanation:
Isotopes are basically atoms of the same element that contain the same number of protons, but a different number of neutrons.
What is homeostasis?
a.
production of urine.
b.
maintaining a stable internal environment.
c.
excretion of waste materials.
d.
none of the above.
Please select the best answer from the choices provided
Answer:
the tendency toward a relatively stable equilibrium between interdependent elements, especially as maintained by physiological processes.
Explanation:
A sample of gas has a volume of 100. L at 17 °C and 800. torr. To what temperature must the gas be cooled in order for its volume to become 50.0 L at a pressure of 600. torr? Your answer will need to be in Kelvin.
Source
StylesNormalFontSize
Answer:
108.81 K
Explanation:
First convert 17 °C to Kelvin:
17 + 273.16 = 290.16 KAssuming ideal behaviour, we can solve this problem by using the combined gas law, which states that at constant composition:
P₁V₁T₂=P₂V₂T₁Where in this case:
P₁ = 800 torrV₁ = 100 LT₂ = ?P₂ = 600 torrV₂ = 50 LT₁ = 290.16 KWe input the data:
800 torr * 100 L * T₂ = 600 torr * 50 L * 290.16 KAnd solve for T₂:
T₂ = 108.81 KHow much energy is released when 2.25kg of water cools from 99.5°C to 4.2°C? 1000g=1kg; 1000J=1kJ; specific heat of water 4.184J/g°C. q=mc∆T
Answer:
897154.2 J
Explanation:
Applying,
q = mcΔT.............. Equation 1
Where q = amount of energy released, m = mass of water, c = specific heat capacity of water, ΔT = Change in temperature
From the question,
Given: m = 2.25 kg = 2250 g, c = 4.184 J/g°C, ΔT = (4.2-99.5) = -95.3°C
Substitute these values into equation 1
q = 2250(4.184)(-95.3)
q = -897154.2 J
q =
Hence the amount of heat released is 897154.2 J
At STP, which gaseous sample has the same number
of molecules as 5.0 liters of O2 (g)?
A) 6.0 L of F2 (g)
B) 4.5 L of O2 (g)
C) 3.0 L of H2 (g)
D) 5.0 L of Cl2 (9)
state the purpose of Watson and crick DNA structure experiment
Answer:
In Watson and Crick's model, the two strands of the DNA double helix are held together by hydrogen bonds between nitrogenous bases on opposite strands. Each pair of bases lies flat, forming a "rung" on the ladder of the DNA molecule.
Explanation:
hope it helps ya
What makes our cells different from bacteria?
A. Our cells are larger.
B. Our cells are rounder.
C. Our cells contain nucleui.
Answer:
C
Explanation:
Bacteria lacks a nucleus.
is it a physical or chemical change when a candle is lit
When sugar is added to a sugar solution, the sugar dissolves. Which term
describes the original sugar solution?
A. Saturated
B. Unsaturated
C. Supersaturated
D. Pseudosaturated
SUBMIT
Answer:
the answer is b,.........
Answer:
Unsaturated
Explanation:
Two planets have similar masses but differ in their distances from the Sun.
Which planet experiences a greater gravitational force with the Sun?
A. The planet that is smaller in volume
B. The planet that is larger in volume
C. The planet that is farther from the Sun
D. The planet that is closer to the Sun
Answer:
D. The planet that is closer to the Sun
How can we protect space shuttles or astronauts from space radiation in the absence of the atmospheric layer?
What is the role of gravity in maintaining the atmospheric layer around the earth ?
Please put your answers with clear explanation.
Thank you !
Answer:Earth's protective magnetic bubble, called the magnetosphere, deflects most solar particles. ... The International Space Station cruises through low-Earth orbit, within Earth's protection, and the station's hull helps shield crew members from radiation too.☘
have a nice day
Upon decomposition, a sample of sodium bicarbonate produces 0.0118 g of sodium carbonate, Na2CO3. How many grams of water does it produce
Answer:
2.00 × 10⁻³ g
Explanation:
Step 1: Write the balanced decomposition reaction
2 NaHCO₃ ⇒ Na₂CO₃ + CO₂ + H₂O
Step 2: Calculate the moles corresponding to 0.0118 g of Na₂CO₃
The molar mass of Na₂CO₃ is 105.99 g/mol.
0.0118 g × 1 mol/105.99 g = 1.11 × 10⁻⁴ mol
Step 3: Calculate the moles of H₂O produced with 1.11 × 10⁻⁴ moles of Na₂CO₃
The molar ratio of Na₂CO₃ to H₂O is 1:1. The moles of H₂O produced are 1/1 × 1.11 × 10⁻⁴ mol = 1.11 × 10⁻⁴ mol.
Step 4: Calculate the mass corresponding to 1.11 × 10⁻⁴ moles of H₂O
The molar mass of H₂O is 18.02 g/mol.
1.11 × 10⁻⁴ mol × 18.02 g/mol = 2.00 × 10⁻³ g
