The molar mass of a compound can be determined by the freezing point depression method. The solution must be relatively dilute and you must know the molal freezing point depression constant of the solvent, Kf. Which statement regarding Kf is true?
A. Kf should be small so that the solvent will not sublimate.
B. Kf will change depending on what solute is dissolved in the solvent.
C. Kf should be negative so the freezing point of the solution will decrease.
D. Kf should be large so the temperature change will be large enough to measure.
Answer:
K should be large so the temperature change will be large enough to measure.
Explanation:
Let us recall that;
∆T = k m I
Where;
∆T= change in boiling point
K= freezing point constant
m= molality
i= Van't Hoff factor
Since the change in temperature depends on k, the larger the value of k the larger the temperature change(Ts - Tb). Hence; K should be large so the temperature change will be large enough to measure.
Ts= freezing temperature of pure solvent
Tb= freezing temperature of solution
is -2 degrees Fahrenheit warmer or is -17 degrees fahrenheit?
Predict the products from reaction of 2-hexyne with the following reagents: (a) 2 equiv Br2 (b) 1 equiv HBr (c) Excess HBr (d) Li in NH3 (e) H2O, H2SO4, HgSO4
Answer:
See explanation and image attached
Explanation:
The reactions of the alkynes involved are shown in the image attached to this answer.
First of all, the reaction of two equivalents of bromine with the alkyne converts it to a saturated compound as shown. One equivalent of HBr converts the alkyne to alkene while excess HBr completely reduces the compound to a saturated compound.
Li/NH3 reduces the alkyne to an alkeneby anti addition to the triple bond.
Reaction of the alkyne with H2O, H2SO4, HgSO4 converts it to an aldehyde as shown.
Underneath the ocean floor, methane can exist as a solid known as methane hydrate. Methane hydrate forms when large amounts of methane become trapped in the crystal structure of water, which develops into a solid similar to ice. A scientist working for a deep water drilling company is studying the properties of the three different phases of methane: methane hydrate, liquified natural gas, and natural gas. Which of the properties is true
Answer:
Methane is present in solid, liquid and gaseous form.
Explanation:
Methane hydrate is present in solid state when the hydrogen-bonded water and methane gas come into contact at high pressures and low temperatures in the deep oceans while on the other hand, methane which is present inside the earth surface in gaseous form due to non-availability of water that can combine with methane. Methane is also found in liquid form when it is cool with high pressure and low temperature.
What do phase diagrams demonstrate?
Select all that apply.
how the melting and boiling points of a substance change with pressure
how much heat will increase the temperature of a gram of a substance by 1°C
the pressure and temperature conditions in which a substance exists as a liquid, solid, or gas
a comparison of the temperature of a substance to the heat absorbed over time
Answer:
this answer is for first one
Explanation:
A higher evalations, where the atmospheric pressure is much lower, the boiling point increase with increased pressure up to the critical point where the gas and liquid properties become identical
give one important characteristic of the particles of matter very sort answer give
Answer:
The important characteristics of the particles of matter are – They are very, very small. They have spaces between them. They are constantly moving.
Answer:
They are very very small
g Write the balanced chemical equation to show the reaction between aqueous silver nitrate and an aqueous solution of barium chloride
Answer:
2AgNO3 + BaCl2 ------> 2AgCl + Ba(NO3) 2.
Explanation:
The precipitate of silver chloride and barium nitrate are formed when barium chloride reacts with silver nitrate. The balanced chemical equation for barium chloride and silver nitrate is 2AgNO3 + BaCl2 ------> 2AgCl + Ba(NO3) 2. In this reaction, two molecules of silver nitrate react with one molecule of barium chloride forming two molecules of silver chloride and one molecule of barium nitrate.
or each conjugate acid-base pair, identify the first species as an acid or base and the second species as the conjugate acid or base of the first. A) CH3COOH and B) CH3COO- A. is _____ B. is _________ C) CH3O- and D) CH3OH C. is _____ D. is _________
Answer:
A. an acid
B. a base
C. conjugate base
D. conjugate acid
Explanation:
This question appears incomplete because it is starting with a "or".
However, the available question can still be answered.
An acid (according to "Bronsted-Lowry") is a chemical compound/specie that can donate hydrogen ion(s) in a reaction while a base is the compound/specie that can receive hydrogen ion(s). From this definition, it can be deduced that CH₃COOH (ethanoic acid) is an acid (weak acid) because it can donate an hydrogen ion while CH₃COO⁻ is a base because it can receive a hydrogen ion.
Also, a conjugate acid is the compound formed when an acid has donated a hydrogen ion to a base (i.e it is a base with hydrogen ion attached to it) while a conjugate base is the acid that has lost it's hydrogen ion. Thus, the conjugate acid in the question is CH₃OH while the conjugate base in the question is CH₃O⁻.
A. an acid
B. a base
C. conjugate base
D. conjugate acid
When 2.50 moles of oxygen reacts with excess hydrogen gas how many grams of water is
produced?
2 H2 + O2--> 2 H20
Answer:
90grams
Explanation:
The reaction given in this question is as follows:
2H2 + O2 → 2H20
Based on this equation, 1 mole of oxygen gas (O2) produces 2 moles of water (H2O)
Hence, 2.50moles of oxygen gas will react with excess hydrogen gas to produce (2.5 × 2) = 5.0moles of water.
Using mole = mass/molar mass
Molar mass of water (H2O) = 1(2) + 16
= 18g/mol
5 = mass/18
mass = 18 × 5
mass of H2O = 90grams
11
Na
Sodium
22.99
What does 22.99 stand for
Someone can you please please help me
Answer:
FalseExplanation:
Target organ toxins are chemicals that can cause adverse effects or disease states manifested in specific organs of the body. Toxins do not affect all organs in the body to the same extent due to their different cell structures.
I need help with the practice question at the bottom. Thank you.
As the gas expands on the surrounding, work is done by the system.
Therefore, W= -279J
Absorbtion of heat,q= +216J
∆U=q+W = (216-279)J= -63J
the pressure of a sample of helium in a 0.150 L container is 1520 torr. if the helium is compressed to the volume of 0.012 L without changing the temperature what would be the pressure of the gas
Answer:
19000 torr
Explanation:
From the question given above, the following data were obtained:
Initial volume (V₁) = 0.150 L
Initial pressure (P₁) = 1520 torr
Final volume (V₂) = 0.012 L
Temperature = constant
Final pressure (P₂) =?
The final pressure of the gas can be obtained by using the Boyle's law equation as illustrated below:
P₁V₁ = P₂V₂
1520 × 0.150 = P₂ × 0.012
228 = P₂ × 0.012
Divide both side by 0.012
P₂ = 228 / 0.012
P₂ = 19000 torr
Thus, the final pressure of the gas is 19000 torr
Which observation provided Albert Einstein the clue that he needed to explain the photoelectric effect?
Answer:
Einstein realized that the energy in electrons was caused by the frequency of light and not the intensity of light. This made him realize that he needed to explain the photoelectric effect.
Explanation:
Einstein realized that the photoelectric effect was a system that should be studied and explained in more depth, when he saw how the energy of electrons behaved in the presence of light. He saw that this energy depends entirely on the frequency of light and not on the intensity of light. From this observation, he realized that the photoelectric effect was essential for the production of an electric energy system, through light energy, such as solar energy.
It is important to note that the photoelectric effect refers to the ejection of electrons on a light surface that comes into contact with a light source.
Observe as equações e de acordo com Brönsted-Lowry, os compostos destacados são, respectivamente
answer
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Predict the product when 2-methylbutanol is oxidised with pyridium chlorochromate in dichloromethane (PCC/CH2C12) a. CH3CH2CH(CH3)COOH b. CH3CH2CH2CH(CH3)CHO C. CH3CH2CH(CH3)CHO d. CH3CH2CH(CH3)OH 8:40 PM Type a message
Answer:
c. CH3CH2CH(CH3)CHO
Explanation:
Hello there!
In this case, according to the process for the one-step oxidation of a primary alcohol with a moderately strong oxidizing agent like pyridinium chlorochromate (PCC), whereby an aldehyde is produced, we infer that the corresponding product will be 2-methylbutanal, which matches with the choice c. CH3CH2CH(CH3)CHO according to the following reaction:
[tex]CH_3CH_2CH(CH_3)CH_2OH\rightarrow CH_3CH_2CH(CH_3)COH[/tex]
Regards!
What molecule is this
Answer:
That is a " ball and stick " model which represents carbon compounds.
Explanation:
This is the answer. Hope it helps you find what you're looking for.
Element X has two naturally occurring isotopes, 35X and 36X . 35X has a percent natural abundance of 30%, while 36X has a percent natural abundance of 70%. What is the average atomic mass of element X
Answer:
= 35.7 amu
Explanation:
Isotopic fractional Wt Avg mass
mass (amu) abundance (= % / 100) = Isotopic mass X (= % / 100)
X-35 35 0.30 10.5 amu
X-36 36 0.70 25.2 amu
__________________________________________________________
Average Atomic Mass of Element X = ∑ Wt. Avg. Masses = 35.7 amu
What is the best tool for making a decorative zucchini or celery twist
Answer:
don't knoe sorry
Explanation:
Which of the following is an alkaline earth metal?
O A. Carbon (C)
O B. Aluminum (AI)
O C. Magnesium (Mg)
O D. Silicon (Si)
Answer:
Magnesium (Mg)
Explanation:
The elements have very similar properties: they are all shiny, silvery-white, somewhat reactive metals at standard temperature and pressure.
Please mark me as brainliest
Thank You
Answer:
The answer is C. Magnesium(Mg)
Pls thank you
Explain carefully what happen to the propanol-water system if approximately
50% of propanol by mass is fractionally distilled. What will be the distillate and
the residue?
Answer:
In the case of mixtures of ethanol and water, this minimum occurs with 95.6% by mass of ethanol in the mixture. The boiling point of this mixture is 78.2°C, compared with the boiling point of pure ethanol at 78.5°C, and water at 100°C. You might think that this 0.3°C doesn't matter much, but it has huge implications for the separation of ethanol / water mixtures. The next diagram shows the boiling point / composition curve for ethanol / water mixtures. I've also included on the same diagram a vapor composition curve in exactly the same way as we looked at on the previous pages about phase diagrams for ideal mixtures.
Name two natural sources of esters.
Answer:
"Esters are widespread in nature and are widely used in industry. In nature, fats are in general triesters derived from glycerol and fatty acids. Esters are responsible for the aroma of many fruits, including apples, durians, pears, bananas, pineapples, and strawberries."
Explanation:
What is the empirical formula of a compound that has a pseudoformula of C3.5H8?
Answer:
The ratio of carbon and hydrogen atoms = 3.5 : 8
= 7 : 16
Then,the empirical formula is C7H16
Match the following terms to their correct definitions.
ResetHelp
A cell that requires energy to bring about a nonspontaneous redox reaction.
An ion-containing conducting medium used to physically and chemically connect the two half-cells in an electrochemical cell.
A cell that requires energy to bring about a nonspontaneous redox reaction.
To move to drop area press Tab key.
faraday
salt bridge
anode
cathode
voltaic cell
electrolytic cell
Answer:
Electrolytic cell. Salt bridge.
Explanation:
Match the following terms to their correct definitions.
A cell that requires energy to bring about a nonspontaneous redox reaction. Electrolytic cell. In an electrolytic cell, energy is provided from an outer source, such as a battery. An ion-containing conducting medium used to physically and chemically connect the two half-cells in an electrochemical cell. Salt bridge. The salt bridge contains a salt (strong electrolyte) and it is fundamental in a voltaic cell.The number of moles of aluminum that react with 15.7 grams of oxygen according to the equation 4 Al + 3 0 2 - 2 Al 20 3
Answer:
Explanation:
1mol of [tex]O_2=2*16{gr\over{mol}}=32{gr\over{mol}}\\\\15.7gr->15.7gr*{1\over{32{gr\over{mol}}}}=0.491mol~of~O_2[/tex]
as 1mol of molecular oxigen reacts with 4 mol of aluminium
1 mol of O2 -----------------------------> 4 mol of Al
0.491 mol of O2 ------------------------------> x
[tex]x={0.491*4\over{1}}~mol~of~Al=1.9625~mol~of~Al[/tex]
Suppose you need to prepare 138.1 mL of a 0.190 M aqueous solution of NaCl. What mass, in grams, of NaCl do you need to use to make the solution
Answer:
Explanation:
· 44 g NaCl Explanation: The problem provides you with the molarity and volume of the target
The answer is rounded to two sig figs, the number of sig figs you have for the molarity of the solution.
The mass of a solute needed to prepare a solution with given volume is find by molarity. The mass of NaCl need to make a 138.1 mL solution of 0.190 M is 1.53 grams.
What is molarity ?Molarity of a solution is a term to express its concentration. Mathematically, it is the ratio of no.of moles of solute to the volume of solution in litres.
Given that, the volume of solution is 138.1 mL. One litre solution is 1000 mL. Hence, 138.1 mL is 0.1381 L. The molarity of the solution is 0.190 M. From these data we can calculate the no.of moles of NaCl as below:
no.of moles = molarity × volume of solution in L
= 0.190 M × 0.1381 L
= 0.0262 moles.
This is the no.of moles required to make the solution.
Molecular mass of NaCl = 58.4 g/mol.
Thus mass of 0.0262 moles of NaCl = 0.0262 mol × 58.4 g/mol
= 1.53 g.
Therefore, the mass of NaCl required is 1.53 g.
To learn more about molarity, refer the link below:
https://brainly.com/question/16727614
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An atom has 6 protons and 9 neutrons in its nucleus. Calculate the mass number of the atom
Answer:
6+9=15
mass number =15
mass number = no. protons + no. of neutrons
A physical chemist measures the temperature inside a vacuum chamber. Here is the result.
T= - 35.903°C
Convert T to SI units.
This is an acronym of the word Systeme International in French. Its International System of Units (SI) is a metric system that would be universally acknowledged as a measurement standard, and the further discussion can be defined as follows:
SI units play an important function in research and innovation in science and technology. In this, the temperature will be measure in the kelvin.Conversion [tex]^{\circ} \ to \ K[/tex]:
let,
[tex]\to 0^{\circ}\ C + 273.15 = 273.15\ K\\\\[/tex]
So,
[tex]\to -35.903+273.15=237.247\ K[/tex]
Therefore, the final answer is "237.247".
Learn more:
brainly.com/question/13347763
What intermolecular force or bond is primarily responsible for the solubility of chlorine (Cl2) in water
The question is incomplete, the common question is;
What intermolecular attractive force is primarily responsible for the solubility of chlorine, Cl2, in water?
a. dipole - dipole
b. hydrogen bonding
c. dipole-induced dipole
d. ion-dipole
e. ion-induced dipole
Answer:
dipole-induced dipole
Explanation:
We have to remember that water is a polar molecule hence it possesses a dipole moment. Its dipole moment is responsible for the ability of water to dissolve many substances.
On the other hand, Cl2 is a nonpolar molecule bound together by only weak dispersion forces.
Recall that dispersion forces involve transient appearance of a dipole in a molecule.
Water molecules can induce a dipole in Cl2 thereby causing the both molecules to interact and Cl2 dissolves in water.
NaCl is ___ formula of common salt
A. Empirical formula
B. Molecular formula
C. Both A and B
D. None of them
