Answer:
.
Explanation:
.
What is the molecular mass for a non-electrolyte if 35.0 g of it is dissolved in 45.0 grams of water and the solutions boiling point is 101.25oC? (The KB for H2O is .51°C/m)
The boiling point of water increases as the amount of impurities dissolved in it increases. For our purposes, we will consider the non-electrolyte to be the dissolved impurity. The change in the boiling point can be calculated using the equation:
[tex]\Delta T_b = i \times K_b \times m[/tex]
where [tex]\Delta T_b[/tex] is the change in boiling point, [tex]i[/tex] is the van ‘t Hoff factor (whose value denotes the number of particles each formula unit of the dissolved substance dissociates into in water), [tex]K_b[/tex] is the boiling point elevation constant, and [tex]m[/tex] is the molality (moles of solute/kilogram of solvent) of the solution.
Right off the bat, since we're dealing with a non-electrolyte, the dissolved substance can be assumed not to dissociate in water. So, our van ‘t Hoff factor, [tex]i[/tex], would be 1 (by contrast, the [tex]i[/tex] for an ionic compound like NaCl would be 2 since, in water, NaCl would dissociate into two particles: one Na⁺ ion and one Cl⁻ ion). We're also given our [tex]K_b[/tex], which is 0.51 °C/m.
Assuming the normal boiling point of pure water to be 100 °C (a defined value for sig fig purposes), the change in boiling point from having dissolved 35.0 g of the non-electrolyte can be obtained by subtracting 100 °C from the final—elevated—boiling point of 101.25 °C:
[tex]\Delta T_b = 101.25\text{ }^o\text{C} - 100\text{ }^o\text{C} = 1.25\text{ }^o\text{C}[/tex]
Now, recall what we're asked to determine: the molecular mass of the dissolved substance. There is one unknown left in the equation: the molality of the solution. Let's first solve for that:
[tex]m = \frac{\Delta T_b}{K_b} = \frac{1.25^\text{ o}\text{C}}{0.51^\text{ o}\text{C}/m} \\ m = 2.45 \text{ mol solute/kg water}.[/tex]
Notice that we didn't include the i since its value is 1.
Now, what would happen if we multiplied our molality by the mass of water we've been given? We would be left with the moles of solute. And what are we asked to find? The molecular mass, or the mass per mole. We can accomplish this in two steps. Remember to convert your mass of water to kilograms:
[tex]2.45 \text{ mol solute/kg water} \times 0.045 \text{ kg water} = 0.110 \text{ mol solute.}[/tex]
And, finally, we divide the mass of our solute by the number of moles of solute:
[tex]\frac{35.0 \text{ g solute}}{0.110 \text{ mol solute}} = 317.5 \text{ g/mol}[/tex]
Our answer to two significant figures (which is the number of sig figs to which our [tex]K_b[/tex] is given) would be 320 g/mol.
What volume, in liters, does 128 grams of O2 occupy at STP?
89.6 L
22.4 L
67.2 L
44.8 L
Answer: 89.7 L
Explanation:
89.6 volume, in liters, does 128 grams of O2 occupy at STP. Therefore, option A is correct.
What do you mean by volume ?A volume is simply the amount of space taken up by any three-dimensional solid. A cube, a cuboid, a cone, a cylinder, or a sphere are examples of solids. Volumes differ depending on the shape.
Every three-dimensional object requires some amount of space. The volume of this space is measured. Volume is defined as the space occupied by an object within the boundaries of three-dimensional space. It is also known as the object's capacity.
1 mole Oxygen has mass 32 grams
Mole of Oxygen in 128 g mass = 128 g / 32 g/mol
= 4.0 mol O2
At Standard temperature and pressure this has volume
= 4.0 mol × 22.4 L/mol
= 89.6 L
Thus, 89.6 volume, in liters, does 128 grams of O2 occupy at STP, option A is correct.
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Use the periodic table to determine which of the
following could be an isotope of bromine (Br).
Check all that apply.
Z = 79, A = 196
Z = 35, A = 79
A = 79, N =44
D Z = 44, N = 44
DONE
ANSWER ASAP THIS IS 6TH GRADE SCIENCE! GIVING BRAINLIEST FIVE STARS ANS A HEART!
Conduction is the transfer of thermal energy through direct contact. Convection is the transfer of thermal energy through the movement of a liquid or gas. Radiation is the transfer of thermal energy through thermal emission.
Answer:
what are you supposed to answer???
Explanation:
Match the special cases of each gas law with its description. A law may be used more than once. In the equations, K is a constant.
A. Boyle's law
B. Charles's law
C. Avogadro's law
D. Dalton's law
____ P1 V1 = P2 V2
____ V/T = k
____ V1 / T1 = V2 / T2
____ V = kn
____ PV = k
____ Ptotal = P1 + P2 + P3 + .
The special cases of gas laws and its description includes:
A. Boyle's law: P1 V1 = P2 V2
B. Charles's law: V/T = k or V1 / T1 = V2 / T2
C. Avogadro's law: V = kn
D. Dalton's law: Ptotal = P1 + P2 + P3 + .
What is gas law?Gas laws are laws that relate a gas's pressure, volume, and temperature. Boyle's law, named after Robert Boyle, states that the pressure P of a gas varies inversely with its volume V at constant temperature, or PV = k, where k is a constant. Charles' law is named after J. -A. -C.
They also include; Gay-Lussac's Law, Avogadro's Law and Dalton's law of partial pressures.
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32 g of CH4 react with 128 g of O2, producing 88 g of CO2. How many grams of water are produced?
Answer:
88 g
Explanation:
32 g of CH4 react with 128 g of O2, producing 88 g of CO2.
How many moles are there in 17.6g NaOH?
Answer:
The answer is 39.99711. We assume you are converting between grams NaOH and mole. You can view more details on each measurement unit: molecular weight of NaOH or mol This compound is also known as Sodium Hydroxide.
Mole measure the number of elementary entities of a given substance that are present in a given sample. Therefore, 0.44moles are there in 17.6g NaOH.
What is mole?The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity or amount of substance. We know one mole of any element contains 6.022×10²³ atoms which is also called Avogadro number. The stoichiometry represents the number of moles.
Mathematically,
number of moles of NaOH =given mass of NaOH÷ molar mass of NaOH
Molar mass of 1 mole of NaOH= 40 g/mol
mass of NaOH= 17.6g
Substituting all the given values in the above equation, we get
number of moles of NaOH = 17.6g ÷ 40 g/mol
number of moles of NaOH =0.44moles
Therefore, 0.44moles are there in 17.6g NaOH.
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___________ mL = 2.2 L
Answer:
2,200 mL I believe it is.
Answer:
2,200 is the answer of your question
Draw a model to represent the physical property of metals known as ductility, or the ability to be drawn into a wire.
The model that represents the physical property of metals known as ductility can be seen in the image attached below.
Metals are substances that are good conductors of heat and electricity.
The term ductility is a characteristic of metal and it explains the ability of metals to be drawn into wire. it implies that metal materials can be hammered and beaten into tiny sheets of wires.
The model in the image attached below shows how gold which is metal is drawn into wires.
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9.
Which element is most likely to conduct heat and electricity?
A. Na B. Ca C.P D. Ne
Answer:
A. Na
Explanation:
Sodium is a good conductor of electricity and heat because it has only one electron in its valence shell.
i hope this helps :)
Answer:
C.) P
Explanation:
I believe this is correct, lmk if it's not.
Bubbles are released when nitric acid is added to a potassium carbonate solution.
What is the net ion
CO2 + H2O --> C2H2 + O2
Answer:
C2H2 + 5 O2 = 4 CO2 + 2 H2O
Add / Edited: 27.09.2014 / 25.01.2015
Evaluation of information: 5.0 out of 5 / number of votes: 2
Source: https://chemiday.com/en/reaction/3-1-0-339
Explanation:
How does Natural selection lead to the Evolution of bacteria?
Answer:
Bacteria can evolve quickly because they reproduce at a fast rate.
Explanation:
Bacteria can evolve quickly because they reproduce at a fast rate. Mutations in the DNA of bacteria can produce new characteristics. A random mutation might cause some bacteria to become resistant to certain antibiotics, such as penicillin.
Which of the following has the smallest atomic radius?
a B
b Al
c F
d N
e Ga
Answer:
c. F
Explanation:
As you go top to bottom down a column of the periodic table, atomic radius increases.
As you go left to right across a period of the periodic table, atomic radius decreases.
Knowing this trend, that means that the smallest atomic radius would be located in the top right of the periodic table. The closest element to that point is fluorine, or answer C.
2H20 → 2H2 + O2
Type of reaction?
Answer:
Notice how the elements splitIt is a decomposition reaction I do exams and quizzes if ur interested
As you climb through the upper stratosphere, the temperature: increases decreases in constant
Answer:
It increases.
Explanation:
I hope this helps.
Answer:
Increases
Explanation:
Hope this helps :)
PLS HELP!!! i have no idea what this could be
Answer:
121.5g
Explanation:
from the equation:
2mol of Al react to give 3 mol of Zn
i.e 81g of Al will give 3×81/2 = 243/2 = 121.5g
what kind of change is heating of mercuric oxide?
Answer:
Chemical change.
Explanation:
When it is heated it decomposes into mercury and oxygen gas. The mercury oxide reactant becomes the silver color of mercury. Hence, a color change can be noticed throughout the reaction.
Answer:
chemical change
Explanation:
How many moles is 118 grams of Argon
Answer:
[tex]\boxed {\boxed {\sf About \ 2.96 \ moles \ of \ Argon}}[/tex]
Explanation:
To convert from grams to moles we must use the molar mass, which is found on the Periodic Table.
Argon: 39.9 g/molUse the molar mass as a ratio.
[tex]\frac{39.9 \ g \ Ar}{1 \ mol \ Ar}[/tex]
Multiply by the given number of grams: 118
[tex]118 \ g \ Ar *\frac{39.9 \ g \ Ar}{1 \ mol \ Ar}[/tex]
Flip the fraction so the grams of argon will cancel each other out.
[tex]118 \ g\ Ar * \frac{1 \ mol \ Ar}{39.9 \ g \ Ar}[/tex]
[tex]118 * \frac{ 1 \ mol \ Ar}{39.9 \ g \ Ar}[/tex]
[tex]\frac {118 \ mol \ Ar }{ 39.9 }[/tex]
[tex]2.95739348 \ mol \ Ar[/tex]
The original measurement of grams had 3 significant figures, so our answer must have 3 sig figs.
For the number we calculated, that is the hundredth place. The 7 in the thousandth place tells us to round the 5 to a 6.
[tex]2.96 \ mol \ Ar[/tex]
There are about 2.96 moles of Argon in 118 grams.
Volume of 8.625 g of sulphur di oxide at RTP in cm3
Answer:
The volume of 8.625 g of sulphur dioxide at RTP is approximately 3,230.84 cm³
Explanation:
The question requires the determination of the volume occupied by the gas based on the molar volume of a gas at STP
The given parameters of the sulphur dioxide, SO₂, gas are;
The mass of the given SO₂ gas = 8.625 g
The molar mass of SO₂ = 64.07 g/mol
The number of moles, 'n', in the given sample of SO₂ gas = Mass of SO₂/(Molar Mass of SO₂)
∴ The number of moles of SO₂ in the gas sample = 8.625 g/(64.07 g/mol) ≈ 0.134618386 moles
The molar volume of a gas at RTP is approximately 24 dm³/mole
24 dm³ = 24,000 cm³
∴ The molar volume of a gas at RTP is approximately 24,000 cm³/mole
The volume occupied by a gas at RTP = (The number of moles of the gas) × (The Molar Volume of a gas at RTP)
∴ The volume occupied by the 8.625 g of SO₂ gas at RTP = 0.134618386 moles × 24,000 cm³/mole ≈ 3,230.84 cm³
The volume occupied by the 8.625 g of SO₂ gas at RTP ≈ 3,230.84 cm³.
The useful energy a light bulb gives out is
(a). kinetic energy (b) chemical energy (c) light energy
science subject
Answer:
Light bulb gives light energy which is usefull
Answer:
(c) light energy
Explanation:
As bulb is used for giving light and hence the energy that it gives is light energy.
How does environmental changes affect animals?
Environmental changes affect animals depending on their ability to adapt to new conditions.
What is adaptation?An adaptation is any type of phenotypic feature associated with a higher fitness in a particular environment.
Adaptations are features that allow organisms to adapt to challenging environmental conditions.
In conclusion, environmental changes affect animals depending on their ability to adapt to new conditions.
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which one of these is NOT a unit for a reaction rate. 1) g/mL 2) M/min
describe a difference in our inner planets and outer planets
Which of these industrial processes typically involves electrolysis?
purifying water for drinking purposes
purifying copper to produce copper wiring for homes
neutralizing an acidic solution by adding a base
neutralizing a basic solution by adding an acid
Answer:
purifying copper to produce copper wiring for homes
Explanation:
Answer:
b.purifying copper to produce copper wiring for homes
Explanation:
The parts of the Earth that contain living organisms
Answer:
Biosphere
The Biosphere --contains all the planet's living things. This sphere includes all of the microorganisms, plants, and animals of Earth. Within the biosphere, living things form ecological communities based on the physical surroundings of an area.
Explanation:
Answer:
Biosphere
Explanation:The Biosphere --contains all the planet's living things. This sphere includes all of the microorganisms, plants, and animals of Earth. Within the biosphere, living things form ecological communities based on the physical surroundings of an area. hope this helps (:
Help out please????
Answer:
B. X= Elements, Y= Compounds
Explanation:
An element is a substance that is made up of only one type of atom. The atoms of an element can combine together chemically to form a molecule but can still exist as an individual atom e.g. Hydrogen atom; H can form molecule H2. Since only one atom makes up an element, its electrons act independently.
Compounds, on the other hand, are substances that are made up of more than one type of atom chemically combined. A compound can only exist as a molecule because it always contains more than one atom bonded together. However, since more than one atom are involved in the chemical bond that holds them together, electrons are shared with other atoms. Example of a compound is H20 containing atoms of hydrogen and oxygen that are chemically combined.
if I have a +2 oxidation number do I give up or accept electrons?
Answer:
I will give up the electrons
Explanation:
Consider the following rules:
1. An atom loses electrons if its oxidation number is positive.
2. An atom gains electrons if its oxidation number is negative.
3. An atom neither gains nor loses electrons if its atomic number is zero.
As I have an oxidation number [tex]+2[/tex] that is oxidation number is positive, so, I will give up electrons.
Hold the slides for observation
How many elements are in (NH4)3PO4
Answer:
4
Explanation:
There are 4 different elements in the compound (N, H, P, O) but if you want to count the number of each element then the answer is different.
In NH4, theres 1 N and 4 H, but since there are 3 NH4s then u have 3 N and 12 H. There's 1 P and 4 Os as well.
Added together u have 3 + 12 + 1 + 4 = 20 elements in total.
hope this helps!