If 5.17 g of an unknown substance X, which is a nonelectrolyte, lowers the freezing point of 200g of benzene ( k = 4.9 C-/m) by 0.84 C what is the molecular weight of X?
Answer:
[tex]M.M=150.8g/mol[/tex]
Explanation:
Hello there!
In this case, according to the given information, it turns out firstly possible for us to set up the equation for the freezing point depression as shown below:
[tex]\Delta T=-i*m*Kf[/tex]
Thus, given Kf, i (equal to 1 because it is nonelectrolyte) and the freezing point depression, we can now calculate the molality of the solution:
[tex]m=\frac{\Delta T}{-i*Kf}=\frac{-0.84\°C}{-1*4.9\°C/m}\\\\m=0.17mol/kg[/tex]
Next, we calculate the kilograms of solvent by dividing the 200 g by 1000 to get 0.200 kg and thus calculate the moles of the solute X:
[tex]n_X=0.200kg*0.171mol/kg\\\\n_X=0.0343mol[/tex]
Finally, the molar mass by dividing the grams by moles:
[tex]M.M=\frac{5.17g}{0.0343mol}\\\\M.M=150.8g/mol[/tex]
Regards!
ionic compounds have __ boiling points and molecular compounds have __ boiling points
a: high,low
b: low,low
c: low,high
d: high,high
Answer:
A
Explanation:
because ionic bond have stronger electrostatic force of attraction between oppositely charged particles so it has higher boiling point than molecular which is covalent bond and have low boiling point hope this helps to understand ^_^
what is used to observe things, like cells, that are too small to see with the naked eye.
Answer:
a microscope is used to see little things the naked eye can't
what is the total number of protons in carbonate, CO2/3- please help
Answer:
30 positive charged protons
Hydrogen peroxide (H2O2) decomposes into water (H2O) and oxygen gas (O2). Hydrogen peroxide is a liquid that is stored in dark-colored bottles in a cool location. Which of these is the MOST likely reason for storing hydrogen peroxide in
this way?
A. Hydrogen peroxide forms crystals when warmed.
B. Exposure to light allows bacteria to grow in hydrogen peroxide.
C. Exposure to light promotes the formation of hydrogen gas (H2) instead of oxygen gas.
D. Hydrogen peroxide breaks down quickly when exposed to light.
Answer:
D
Explanation:
the H2O2 under go reduction to remove O2 and then forms water
Hospital patients are administered oxygen from an pressurized
hyperbaric oxygen chamber. 600.0 L of oxygen is compressed in a
cylinder at 160.0 atm. What volume of oxygen can a cylinder supply at a
pressure of 3.0 atm?
Answer:
32000atm
Explanation:
Using Boyle's law equation;
P1V1 = P2V2
Where;
P1 = initial pressure (atm)
P2 = final pressure (atm)
V1 = initial volume (
V2 = final volume (L)
According to the question below:
P1 = 160.0 atm
P2 = 3.0 atm
V1 = 600L
V2 = ?
Using P1V1 = P2V2
160 × 600 = 3 × V2
96000 = 3V2
V2 = 96000/3
V2 = 32000atm
what do the letters in the boxes of the periodic table represent
Answer:
The letters are a one- or two-letter symbol assigned to each element.
Explanation:
What is pOH? ?
A. pOH = Iog[ΟΗ]
Ο Ο Ο
Β. pH = Iog[Η]
Ο C. pH = Iog[ΟΗ]
D. pOH = [Η
(OH)
What is the mass of 3.01 x10^23 molecules of ammonia?
For each of the following sets of elements, state whether all of the elements are in the same group, the same period, or neither the same group or the same period.
a. Fe, Ru, Os
b. Rh, Pd, Ag
c. Sn, As, S
d. Se, Te, Po
Answer:
a. Same group, different period
b. Different group, same period
c. Different group, different period
d. Same group, different period
I need help with both of the questions fast plz!!!
Answer: SMALLEST is lithium
LARGEST is Fluorine
Explanation:
Q4. A grasshopper jumps at an angle of
30° to the horizontal with a take off
speed of 3m/s
1.
What is the height of its jump? (2)
II.
How long is it above the ground?
(2)
III.
What is the range of its jump? (2)
Answer:
i. The height of its jump is approximately 0.115 m
ii. The time of flight of its jump is approximately 0.306 seconds
iii. The range of its jump is approximately 0.795 m
Explanation:
The angle at which the grasshopper jumps, θ = 30°
The speed with which the grasshopper takes off, u = 3 m/s
i. The height of its jump 'h', is given by the following relation;
[tex]h = \dfrac{u^2 \times sin^2 \theta}{2 \times g}[/tex]
Where;
g = The acceleration due to gravity ≈ 9.81 m/s²
Therefore;
[tex]h \approx \dfrac{3^2 \times sin^2 (30^{\circ})}{2 \times 9.81} = \dfrac{25}{218} \approx 0.115[/tex]
The height of its jump, h ≈ 0.115 m
ii. The time of flight of its jump, 't', is given as follows;
[tex]The \ time \ of \ flight, \, t = \dfrac{2 \times u \times sin \theta}{ g}[/tex]
Therefore;
[tex]t \approx \dfrac{2 \times 3 \times sin (30 ^ {\circ})}{ 9.81} = \dfrac{100}{327} \approx 0.306[/tex]
The time of flight of its jump, t ≈ 0.306 seconds
iii. The range of the jump is given by the following projectile motion equation for the range as follows;
[tex]R = \dfrac{u^2 \times sin (2 \times \theta)}{ g}[/tex]
Therefore;
[tex]R \approx \dfrac{3^2 \times sin (2 \times 30^ {\circ})}{ 9.81} = \dfrac{41659} {52433} \approx 0.795[/tex]
The range of the jump, R ≈ 0.795 m.
number of moles of sodium azide
Answer:
0.015382279644614 mole.
Answer:
yes this is the answer for that quaz
Write a neutralization reaction to form the salt k2so4
H2SO4 + 2KCL ----------› K2SO4 + 2HCL
hope it helps you ♡♡
an atom has 19 protons and 20 neutrons. what is the atomic number with steps
Answer:
39
Explanation:
add em up
Which is most likely a physical change?
Answer:
Examples of physical change include changes in the size or shape of matter. Changes of state—for example, from solid to liquid or from liquid to gas—are also physical changes. Some of the processes that cause physical changes include cutting, bending, dissolving, freezing, boiling, and melting.
Explanation:
The temperature of a 95.4 g piece of copper decreases from 48°C to 25°C when the copper releases - 849 J of heat. What is the specific heat of copper?
Propane burns to form carbon dioxide and water. The equation for the reaction is:
C 3 H 8 (g)+5 O 2 (g) 3 CO 2 (g)+4 H 2 O(l)
3.60d * m ^ 3 carbon dioxide is produced when a sample of propane is burned in 7.25d * m ^ 3 oxygen.
Calculate the volume of unreacted oxygen. Give your answer in cm^ 3
Answer:
Propane burns to form carbon dioxide and water. The equation for the reaction is:
C3H8 (g)+5O2 (g) -> 3CO2 (g) + 4H2O(l)
Explanation:
From the balanced chemical equation, it is clear that:
1mol. of propane reacts with 5 mol. of O2 and forms 3 mol. of CO2.
In terms of volume, the above equation can be rewritten as:
1.0L. of propane reacts with 5.0L O2 and forms 3.0L of CO2.
Since,
[tex]1dm^{3} =1.0L[/tex]
3.60dm^3 of CO2 is formed from how many dm^3 of O2?
[tex]=>3.60dm^3 CO2 * \frac{5.0L O2}{3.0L CO2}\\=6.0dm^3 O2 \\=6.0L O2[/tex]
The volume of unreacted oxygen is:
[tex]7.25dm^3 -6.0dm^3\\=1.25dm^3[/tex]
The volume of unreacted oxygen is 1.25L or 1250cm^3.
Since,
1dm^3=1000cm^3.
Which term best describes Cl in the following reaction? (HELP ASAP)
2NH3 + (OCl)– → N2H4 + H2O + Cl–
A)
Reducing agent
B)
Oxidized
C)
Reduced
D)
Electrolyte
i'm thinking reduced maybe but not sure
Answer:
Yes it is reduced because ocl is the reducing agent
What is a likely result of an increase in average global temperatures on Earth?
A. More predictable weather
B. Rising sea levels
C. Fewer rainstorms and blizzards
D. Falling sea levels
Answer:
A.
Explanation:
Warmer temperatures can also lead to a chain reaction of other changes around the world. That's because increasing air temperature also affects the oceans, weather patterns, snow and ice, and plants and animals. The warmer it gets, the more severe the impacts on people and the environment will be.
Why do you think there was a rush to mass-produce penicillin around the time of World War II?
Answer:
penicillin could protect mice against infection from deadly Streptococci.
Explanation:
Answer:
In 1940, Florey carried out vital experiments, showing that penicillin could protect mice against infection from deadly Streptococci.
I'll give brainliest. My group has been struggling to answer this. We just need a solid answer with work to pick up our grades at least.
How many grams of Al(OH)3 are produced from 3.00 g of AlCl3 with excess of NaOH?
Explanation:
here u go the Answer with the working:)
how many types of kinetic energies are there? is it 4 or 5 types?
Which of the following would eat a dead rabbit?
A)
carnivore
B)
scavenger
C)
herbivore
D)
omnivore
Answer:
Scavenger
Explanation:
Because scavengers feed on dead of decaying meat
Differentiate between compounds and mixtures using the particle model of
matter.
Answer:
compounds are substance which can be formed by chemically combining two or more elements.
mixtures are substance that are formed by physically mixing two or more substances
This chemical reaction follows the law of conservation of mass. CaO(s) + CO2(g) - CaCO3(s) How much CaCO, will be formed if 2.2 grams of CaO are used for this reaction? Assume there are enough reactants to complete the reaction. The final answer should be rounded to one place after the decimal point.
4.3 grams 2.2 grams 1.1 grams 3.9 grams
please answer quick!
Answer:
the answer is 1.1grams is the currect ans
According to the law of conservation of mass, 1.1 grams of calcium carbonate are formed if 2.2 grams of CaO are used for this reaction.
What is law of conservation of mass?According to law of conservation of mass, it is evident that mass is neither created nor destroyed rather it is restored at the end of a chemical reaction .
Law of conservation of mass and energy are related as mass and energy are directly proportional which is indicated by the equation E=mc².Concept of conservation of mass is widely used in field of chemistry, fluid dynamics.
Law needs to be modified in accordance with laws of quantum mechanics under the principle of mass and energy equivalence.This law was proposed by Antoine Lavoisier in the year 1789.If 56 g CaO gives 46.2 g calcium carbonate then 2.2 g CaO will give 2.2×46.2/56=1.1 g.
Learn more about law of conservation of mass, here:
https://brainly.com/question/28711001
#SPJ6
Explain if the combination of iron and copper sulfate is an example of a chemical reaction. Use evidence and scientific reasoning to support your answer.
Which of these reactions shows simple chemical decomposition?
I2 + 2NaCl → 2Nal + Cl2
NaF + HCl → HF + NaCl
H2 + I2 → 2HI
2NaCl → 2Na + Cl2
Answer:
last option is the correct answer
Explanation:
you can see that the chemical NaCl is decomposed or broken into its components Na and Cl.
all other equations have formation of a new compound by reaction of 2 elements or compound
Which of the following accurately describes a Brønsted-Lowry acid?
A)
A Brønsted-Lowry acid receives a protein and has a matching conjugate acid.
B)
A Brønsted-Lowry acid donates a proton and has a matching conjugate base.
C)
A Brønsted-Lowry acid receives a proton and has a matching conjugate base.
D)
A Brønsted-Lowry acid donates a protein and has a matching conjugate acid.
Answer:
B. A Brønsted-Lowry acid donates a proton and has a matching conjugate base.
Explanation:
Here's HA is bronsted acid and its conjugate base pair is A-.
Answer:
Explanation:
The actual answer is B. The equation has an acid on one side and a base on the other. The acid donates a proton. Donates means gives up the equivalent of a proton.
Calculate the molality of a solution that contains 51.2 g of naphthalene, C10H8, in 500 mL of carbon tetrachloride. The density of CCl4 is 1.60 g/mL.
Answer: The molality of naphthalene solution is 0.499 m
Explanation:
Density is defined as the ratio of mass and volume of a substance.
[tex]\text{Density}=\frac{\text{Mass}}{\text{Volume}} [/tex] ......(1)
Given values:
Volume of carbon tetrachloride = 500 mL
Density of carbon tetrachloride = 1.60 g/mL
Putting values in equation 1, we get:
[tex]\text{Mass of carbon tetrachloride}=(1.60g/mL\times 500mL)=800g[/tex]
Molality is defined as the amount of solute expressed in the number of moles present per kilogram of solvent. The units of molarity are mol/kg. The formula used to calculate molarity:
[tex]\text{Molality of solution}=\frac{\text{Given mass of solute}\times 1000}{\text{Molar mass of solute}\times \text{Mass of solvent (in g)}}[/tex] .....(2)
Given values:
Given mass of naphthalene = 51.2 g
Molar mass of naphthalene = 128.17 g/mol
Mass of solvent = 800 g
Putting values in equation 2, we get:
[tex]\text{Molality of naphthalene}=\frac{51.2\times 1000}{128.17\times 800}\\\\\text{Molality of naphthalene}=0.499m[/tex]
Hence, the molality of naphthalene solution is 0.499 m
