Answer:
a
Explanation:
the flying squirrel the air guides to navagate in the air
Cuál es el punto de ebullición de una solución acuosa de urea al 20 % m/m (20g de soluto por cada 80g de solvente) , si la masa molar de urea es 60 g/mol. (Ke= 0,52 °C/m)
The question is: What is the boiling point of an aqueous solution of urea at 20% m / m (20g of solute for every 80g of solvent), if the molar mass of urea is 60 g / mol. (Kb = 0.52 ° C / m)
Answer: The boiling point of given aqueous solution of urea is [tex]2.145^{o}C[/tex].
Explanation:
Given: Mass of solute = 20 g
Mass of solvent = 80 g (1 g = 0.001 kg) = 0.08 kg
[tex]K_{b} = 0.52^{o}C/m[/tex]
Molar mass of urea = 60 g
Molality is the number of moles of solute present in a kg of solvent.
Moles is the mass of a substance divided by its molar mass. So, moles of urea is calculated as follows.
[tex]Moles = \frac{mass}{molar mass}\\= \frac{20 g}{60 g/mol}\\= 0.33 mol[/tex]
Now, molality of given solution is as follows.
[tex]Molality = \frac{moles}{mass(in kg)}\\= \frac{0.33 mol}{0.08 kg}\\= 4.125 m[/tex]
Formula used to calculate the boiling point is as follows.
[tex]\Delta T_{b} = K_{b}m\\= 0.52^{o}C/m \times 4.125 m\\= 2.145^{o}C[/tex]
Thus, we can conclude the the boiling point of given aqueous solution of urea is [tex]2.145^{o}C[/tex].
0 / 5 points
Order the following chemicals from lowest to highest melting point.
Water
Paraffin wax
Hydrogen sulfide
Ethanol
Carbon dioxide
Answer:
Ethanol - -173.5°FHydrogen sulfide - -121.9°FCarbon dioxide - -69.9 °FWater - 32°FParaffin wax - 115 to 154 °FExplanation:
Ethanol is a chemical, grain alcohol is a volatile and flammable, colorless, and odorless substance. The versatile solvent has many acidic compositions. Paraffin wax is an soft and colorless solid that is made from petroleum coal and oil. It is an excellent material for storing heat.hii pls help me with this ionic equation
Answer:
net ionic equation
[tex]\boxed{ CaCO_3{}_{(s)} + 2H^{+} {}_{(aq.)} \rightarrow Ca^{2+} {}_{(aq.)} + H_2O_{(l)} + CO_2{}_{(g)} } [/tex]
number of protons in carbon-12
Answer:
6
Note:
Please check Rasputin020's answer instead of this, It's more detailed.
True or false, The ideal gas lead allows us to figure out a fourth variable about a gas when the other 3 are given
Answer:
true
Explanation:
PV=nRT
The ideal gas law states that PV = NkT, where P is the absolute pressure of a gas, V is the volume it occupies, N is the number of atoms and molecules in the gas, and T is its absolute temperature. The constant R is called the Boltzmann constant
A sample of hydrogen gas H2 has a volume of 5.0 L and a pressure of 1.0 atm. What is the final pressure in atmospheres if the volume is decreased to 2 L with no change in temperature and amount of gas
Answer:
2.5 atm
Explanation:
P = Pressure
V = Volume
P1V1 = P2V2
1 x 5 = P2 x 2
5 = P2 x 2
Divide both sides by 2
5/2 = P2 x 2/2
P2 = 2.5
A sealed piston contains 400 mL of air at standard ambient pressure. The piston is
compressed to an internal volume of 125 mL while keeping a constant temperature,
What is the new internal pressure (in kPa) of the air?
Answer:
324.24 kPa
Explanation:
Given that;
Initial pressure P1 = 101325 Pa
V1= 400 ml
P2 = ?
V2= 125mL
From Boyle's law;
P1V1 = P2V2
P2 = P1V1/V2
P2= 101325 × 400/125
P2= 324.24 kPa
What is the redox half equation for 3Ag2S + 2Al --> 6Ag + Al2, and identity which material is oxidized and which is reduced? :)
Answer:
Al is oxidized while Ag is reduced.
Explanation:
The complete molecular equation is;
3Ag2S + 2Al --> 6Ag + Al2S3
Oxidation half equation;
2Al ------> 2Al^3+ + 6e
Reduction half equation;
6Ag^+ + 6e -------> 6Ag
Overall redox reaction equation;
2Al + 6Ag^+ ----->2Al^3+ + 6Ag
Hence; Al is oxidized while Ag is reduced.
2HGO(s) + 43.4 kcal -> 2Hg(I) + O2(g)
Answer:
x = -9, 0 = -1, x \ne 0
Explanation:
[-54/x = 6 0x = 9]
Isolate x for - 54/x = 6 : x = -9
-54/x = 6
Multiply both sides by x
-54/x = 6x
Simplify - 54/x x : -54
-54x x = 6x
Multiply fractions: a . b/c = a . b/c
= -54x/x
Cancel the common factor: x
= -54
- 54 = 6x
Switch sides
6x = -54
Divide both sides by 6
6x/6 = -54/6
Simplify
6x/6 = -54/6
Simplify 6x/6: -9
6x/6
Divide the numbers: 6/6 = 1
= x
Simplify
-54/6
Apply the fraction rule: -a/b = -a/b
= -54/6
Divide the numbers: 54/6 = 9
= -9
x = -9
Verify solutions
Find underfined (singularity) point: x = 0
Take the denominator (s) of - 54/x and compare to zero
x = 0
Combine undefined points with solutions:
x = -9
Substitute x = -9
[ o(-9) = 9]
Simplify
0(-9) = 9
Simplify
0(-9): -90
Remove parentheses: (-a) = -a
= -0 . 9
-90 = 9
[-90 = 9]
Isolate o for -90 = 9 : o = -1
-90 = 9
Divide both sides by -9
-90/-9 = 9/-9
Simplify
0 = -1
The solutions to the system of equations are:
x = -9, 0 = -1, x \ne 0
............................
How many electrons would make the d shell complete?
Use an aufbau diagram.
1
2
6
10
Answer:
D
Explanation:
The answer for the first question is definitely D. 10, as it is a neutral atom, therefore numbers of p+ and e- are the same.
Hope it helps you
According to the electronic configuration and capacity of shells there are 10 electrons that would make the d shell complete.
What is electronic configuration?Electronic configuration is defined as the distribution of electrons which are present in an atom or molecule in atomic or molecular orbitals.It describes how each electron moves independently in an orbital.
Knowledge of electronic configuration is necessary for understanding the structure of periodic table.It helps in understanding the chemical properties of elements.
Elements undergo chemical reactions in order to achieve stability. Main group elements obey the octet rule in their electronic configuration while the transition elements follow the 18 electron rule. Noble elements have valence shell complete in ground state and hence are said to be stable.
Learn more about electronic configuration,here:
https://brainly.com/question/29157546
#SPJ6
Calculate the solubility of Maslog at 25€
4 30-0cm of its Saturated solution at that
temperature gave 180g of the anhydrous
C= 12. 0-46. Ma =23
Salt
Answer:
20
Explanation:
calculated saturated solutions
Over a period of 2 minutes, 180 coulombs of charge pass through a resistor. What is the current through the resistor during this time?
Type the correct answer in the box. Use numerals instead of words.
The current through the resistor during this time is
A.
Answer:
Explanation:
Formula
The current = charge / time
The charge is in coulombs
The time has to be in seconds.
1 minute = 60 seconds
2 minutes = 120 seconds.
charge = 180 coulombs
current = 180 / 120
current = 1.5 amperes.
what is solution, colloid, suspension?
Explanation:
SOLUTION:Solution is a homogenous mixture of two or more substances in relative amounts that can be varied continuously up to what is called the limit of solubility.
COLLOID:A mixture in which one substance is divided into minute particles (called colloidal particles) and dispersed throughout a second substance
SUSPENSION:A suspension is a heterogeneous mixture of a finely distributed solid in a liquid. The solid is not dissolved in the liquid, as is the case with a mixture of salt and water.
On a plateau on a heating curve, _____.
phase changes are occurring
no heat is being absorbed
all the absorbed heat is being used to overcome forces of attraction between the particles or molecules and phase changes are occurring
all the absorbed heat is being used to overcome forces of attraction between the particles or molecules
Answer:
On a Plateu on a heating curve phase changes are occuring
Explanation:
The first Phase is melting during which the temrature stays the same while water melts.Other phase changes are freezing sublimation Vaourization condensation and deposition
which best describes the relationship between internal energy and thermal energy
Answer:
answer is d on edge
Explanation:
All atoms of the same element:
have the same number of atoms
have the same number of protons
have the same number of neutrons
have the same number of electrons
Answer:
have the same number of protons
what is the molarity of HCL solution that has a density of 1.17g/ml at 25°?
Here, we have been given that;
$ \bf{1 ml}$ = 1.17 g$ \bf{1 l}$ = 1170 gHence, we can note that,
No. of moles of HCL (n) = $ \sf{\frac{1170}{36.5}}$(n) = 32.05
[tex] \\ [/tex]
Thus,
Molarity = 32.05 mg/LHence, molarity of the given solution will be 32.05 mg/L.
What makes a strong acid different from a weak acid?
Answer:
Strong acids react faster whereas weak acids take time to react with any base.
Strong acids are good conductors of electricity on contrary weak acids are not too good as conductors of electricity.
Strong acid passes electricity faster whereas weak acids are slow conductors.
Strong acids are not edible but weak acids are edible.
Strong acids have ph value ranging between 0 to 3 but the ph value of weak acids ranges between 5 to below 7.
6. What parts of a nuclear reactor keep the reaction from
becoming too vigorous and causing a nuclear accident?
A. Turbine and generator
B. Control rods and moderators
C. Shield and containment system
D. Condenser and cooling tower
Answer:
B. control rods and moderators
40 POINTS!! Will Mark Brainliest if all work is shown as well as correct answer
The following reaction can be used to convert carbon dioxide to oxygen gas.
4 KO₂ (s) + 2 CO₂(g) → 2 K₂CO₃(s) + 3 O₂(g)
The theoretical yield for the reaction is 0.296 g O₂. Given that the reaction has a percent yield of 83.4%, what is the mass in g of oxygen gas that is actually produced?
Answer:
0.3549
Explanation:
the percentage yield is the percentage of the product formed based on the theoretical yield.in this question the percentage yield and theoretical yield have been given all that's left is the actual yield.so you use the formula
percentage yield=theoretical yield/actual yield×100
83.4=0.296/ay×100
83.4ay/83.4=100×0.296/83.4
ay=0.3549
I hope this helps
solve this
The first one is the Bromine water test
the second is the Baeyers test
Third is addition reaction
1 CH3-CHBR-CH2BR
2.CH3-CH2-CH3
3.CH3-CHCL-CH2CL
True or false, We use the ideal gas law when a gas changes
we use the ideal has law when a bad changes false
what structure does solid lead (11)fluoride have
plz answer (g) i will give rating 5 and thanks who answer plz fast
Answer:
Like many common group 2 metal carbonates, magnesium carbonate reacts with aqueous acids to release carbon dioxide and water
MgCO3 + 2 HCl → MgCl2 + CO2 + H2O.
The procedure to obtain pure magnesium chloride from the reaction is as thus
Step 1: Reaction
- Leave the dilute hydrochloric acid in a beaker.
- Add Magnesium carbonate slowly until it is in excess or until no more gas seem to be getting liberated.
Step 2: Filtration
- Filter with filter paper and funnel.
- Filter off the excess magnesium carbonate as magnesium chloride will be in aqueous form (liquid) and will come out with the filtrate. The residue is the excess magnesium carbonate.
Step 3: Crystallization to obtain solid crystals from the filtrate.
- Pour filtrate solution into evaporating dish/basin
- Provide heat using Bunsen burner
- Pour solution into an evaporating basin and heat over a water bath
- Stop heating when crystals start to form
allow water to evaporate until pure crystals remain.
- Dry crystals using absorbent paper or warm oven.
Precautions
- Use personal protective equipment such as gloves, a lab coat and wear eye protection, especially when heating.
- Avoid inhaling unnecessary gases during the whole process.
What element has the electron configuration 1522s22p63s23p4?
Answer:
Sulphur
Explanation:
1s² 2s² 2p⁶ 3s² 3p⁴
So in total ya got 16 electrons
3===> defines the period
4+12===> defines the group
and boom, there ya got yaself an element called sulphur
Can someone answer this ASAP?
Carbon has unique bonding characteristics that allow it to
A
form ionic bonds with any atom to form many different molecules.
B
resist bonding with other atoms and remain a pure element.
С
form chains or rings by bonding to itself and other atoms.
D
form ionic salts that make up half of the known salts on Earth.
Answer:
С. form chains or rings by bonding to itself and other atoms.
Explanation:
Carbon is an element in group 4 of the periodic table with unique bonding properties. Carbon posseses 4 valence electrons in its outer shell. This enables carbon to form covalent bonds with the atoms of other elements e.g. nitrogen, phosphorus, oxygen, hydrogen etc.
Carbon can also combine covalently with other carbon atoms i.e. C-C to form long chains and rings in a process called CATENATION. This unique property of carbon makes it the only element that can form so many different compounds.
8. What is the oxidation number of N in KNO3?
Answer:
The oxidation state of N in the KNO3 is +5
Explanation:
Oxidation rules:
1. Oxygen is -2, unless in peroxides.
2. Group 1 metals = +1
3. Group 2 metals = +2
4. If the molecule is neutral, all of the oxidation numbers have to add up to zero.
5. If the molecule is charged, all of the oxidation numbers have to add up to the charge of the molecule.
So, the given formula represents the salt compound formula unit of potassium nitrate: KNO3
The formula unit is uncharged.
From our rules, we know that,
O = -2
And we can find K on the periodic table, in the first group, thus giving it a +1 charge. Now let's put it all together.
K = +1
N = x
O = -2
Let's take into account the number of atoms of each element we have and make an equation since we know everything has to add up to zero since the molecules are neutral.
+1 +x+3 (-2) = 0 (notice we multiplied 3 by -2 because in the formula we have 3 atoms of oxygen with -2 charge each)
x - 5 = 0
x = 5
Therefore, the oxidation number of N in KNO3 is +5.
Which statement accurately describes the evidence that scientists gather using fossils? Check all that apply.
Complete question is;
Which statements accurately describe the evidence that scientists gather using fossils? Check all that apply.
A) The fossil record can be used to date rocks.
B) Living things with many cells have always lived on Earth.
C) Simple organisms are found only in young rocks.
D) Geologists study ancient remains of plants and animals.
E) Scientists can figure out what ancient living things ate.
F) Pollen and seeds help provide clues about ancient climates.
Answer:
A) The fossil record can be used to date rocks
E) Scientists can figure out what ancient living things ate.
F) Pollen and seeds help provide clues about ancient climates
Explanation:
In scientific research, fossils are sometimes referred to as animals and plant. Now, in studying records of fossils, it will be easy to know the length of existence of living things on the Earth. Also, we can be able to identify the manner in which different relationships exists between plants and animals by predicting their lifestyles, location of their habitation e.t.c which can be used to predict the old time climates.
Looking at the options given in relation to the explanation given, options A, E & F are correct
Predict what would happen if a scientist added potassium to a dilute acid.
Potassium reacts with dilute hydrochloric acid to give potassium chloride and hydrogen gas. Heating small pieces of Potassium in air results in the substance melting without any flame being seen and turning instantly into a mixture of potassium peroxide and potassium super oxide.
A Potassium Reaction involves a process in which Potassium is mixed with another substance which react to form something else. Reactions are manifested by the disappearance of properties characteristic of Potassium and the appearance of new properties in the new substance or Compound.
The substances initially involved in a reaction are called reactants or reagents. The most important of the Potassium compounds is Potassium chloride (KCl) which is used in the production of fertilizers and chemicals and also as a salt substitute. Other important compounds are Potassium nitrate (KNO3), also known as saltpeter which is used in the production of gunpowder, fertilizers and pyrotechnics and Potassium hydroxide (KOH) is used to make detergents and soaps. Reactions are described with Chemical Formula and Equations.
