Chất tinh khiết là:

A. Có tính chất thay đổi

B. Có lẫn thêm vài chất khác

C. Gồm những phân tử đồng dạng

D. Không lẫn tạp chất

Answers

Answer 1

Answer:

The FitnessGram™ Pacer Test is a multistage aerobic capacity test that progressively gets more difficult as it continues. The 20 meter pacer test will begin in 30 seconds. Line up at the start. The running speed starts slowly, but gets faster each minute after you hear this signal. [beep] A single lap should be completed each time you hear this sound. [ding] Remember to run in a straight line, and run as long as possible. The second time you fail to complete a lap before the sound, your test is over.

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Related Questions

What is the pH value of lithium chloride?

Answers

Answer:

0.0003

HERE IS YOUR ANSWER

PLZ HELP Question 14 of 25 What is the name for a representation of the physical world?
A. Model
B. Compound
C. Atom
D. Alloy SUBMIN​

Answers

Answer:

Model

Explanation:

A model of anything is something you make to represent it in it's physical world form

solubility of salt at 10 degree Celsius is 20 how does it what does it means what happens if the temperature of saturated solution is increased and decreased explain it in detail​

Answers

Answer:

solubility of salt at 10 degree Celsius is 20 how does it what does it means what happens if the temperature of saturated solution is increased

Explanation:

solubility of salt at 10 degree Celsius is 20 how does it what does it means what happens if the temperature of saturated solution is increased

The density of water is 1 g/cm3. Brent used the following method to convert 1 g/cm3 to kg/m3. An equation is shown. The expression on the left has three terms separated by the multiplication sign. The first term is 1 g by 1 cubic cm. The second term is 1 kg by 1000 kg. The third term is 100 cm raised to the power of 3 divided by 1 m raised to the power of 3. The number on the right of the equal to sign is 1000 kg per cubic meter. (1 kg = 1,000 g and 1 m = 100 cm) What is the error in Brent's conversion method?

Answers

Answer:

The error includes;

a) The wrong denominator for the equivalent fraction of kilograms to grams

b) The use of the scale factor of length rather than the scale factor of volume for the equivalent fraction of cubic centimeters to cubic meters

c) The arrival at the correct 1000 kg/m³ rather than 0.1 g/m³ based on the expression on the left of the equation

Explanation:

The density of water = 1 g/cm³

The given equation is presented as follows;

1 g/cm³ × 1 kg/(1000 kg) × 100 cm³/(1 m³) = 1000 kg/m³

The error in the conversion method are;

a) The conversion, 1 kg/(1,000 kg) has an error, the correct conversion is (1 kg)/1,000 g)

b) The volume conversion error, 100 cm³/(1 m³), the correct volume conversion is (100 cm)³/(1 m³) = 1,000,000 cm³/(1 m³)

c) The right of the equal to sign error; using the left side expression only, the (wrong) answer is 0.1 g/m³

The correct equation is presented as follows;

1 g/cm³ × 1 kg/(1000 g) × 1,000,000 cm³/(1 m³) = 1000 kg/m³

Answer:

C. 1,000 kg should be written as 1,000 g.

Explanation:

Got it right on my test :)

Can Some One Please Help Me

Answers

Answer:

12 g

Explanation:

From the question given above, the following data were:

Number of atoms = 6.02×10²³ atoms

Mass of ₆C¹² =?

From Avogadro's hypothesis,

1 mole of any substance contains 6.02×10²³ atoms. This implies that 1 mole of ₆C¹² also contains 6.02×10²³ atoms i.e

1 mole of ₆C¹² = 6.02×10²³ atoms

Recall

From the period,

1 mole of ₆C¹² = 12 g

Thus,

12 g of ₆C¹² = 6.02×10²³ atoms

Therefore, 12 g of ₆C¹² contains 6.02×10²³ atoms

Type the correct answer in the box. Express your answer to two significant figures. You are performing a reaction with 1.7 moles of hydroiodic acid and 3.43 moles of zinc bromide: 2HI + ZnBr2 → 2HBr + ZnI2. How many moles of zinc iodide can be made? The theoretical yield is moles of zinc iodide.

Answers

Answer:

1.34 34343 he did

Explanation:

i did the test

Answer:

0.85

Explanation:

****************************************************************

Answers

******************* ijustwantthepoints *************************

Câu 6: Cho 4,2 gam este đơn chức no E tác dụng hết với dung dịch KOH ta thu được 4,76

gam muối natri. Vậy công thức cấu tạo của E có thể là:

Answers

Please translate this in English or Korean and I’ll be happily help :)

Sorry I just don’t understand this language nor know It or I would translate myself

PLZ HELP ME WITH MY WORK​

Answers

Answer:

Explanation:

pretty sure its mixure.

Mixture








I’m sure mann

Which factor would speed up a chemical reaction? (Choose all that apply)
Decreasing particle size
Increasing the temperature
Decreasing the temperature
Increasing particle size

Answers

Answer:

Increasing the temperature

Increasing particle size

Explanation:

Increasing the temperature allows for particles and molecules to move faster (because there is an increase in energy) and allows for more collisions.

∴ Increasing the temperature would be an answer.

Increasing the particle size allows for more surface area and a greater chance for particles to collide with each other.

∴ Increasing particle size would be an answer.

Topic: AP Chemistry

Unit: Kinetics

Câu 1: Trong các dung dịch sau, dung dịch nào làm quỳ tím đổi màu xanh?
A. HCl B. H2SO4 C. NaOH D. NaCl
Câu 2: Bazơ nào dưới đây là bazơ không tan?
A. KOH B. NaOH C. Cu(OH)2 D. Ca(OH)2
Câu 3: Trong các chất sau đây, chất nào không phải là muối?
A. HCl B. KCl

Answers

C. NaOH

C. Cu (OH)

A. HCl

0.2g of water represents how many mole?

Answers

Answer:

0.0111moles

Explanation:

as moles = mass/ mr(16+1+1)

so 0.2g / 18

gives you 0.111moles

hope this helps :)

Tenemos una disolución de HNO3 cuya pureza es del 65% y tiene una densidad de 1.32 g/mL. ¿Cuál es la molaridad de la disolución? PM HNO3 = 63.0 g/mol.

Answers

Teniendo en cuenta que la molaridad es el número de moles de soluto que están disueltos en un determinado volumen, la molaridad de la disolución de HNO₃ es 14.67 [tex]\frac{mol}{L}[/tex].

El porcentaje en masa o en peso de una disolución es el número de gramos de soluto que hay por cada 100 gramos de disolución.

Entonces una pureza de 65% indica que hay 70 g de HNO₃ puro por cada 100 g de HNO₃ impuro.

Por otro lado, la densidad es la relación entre el peso o masa de una sustancia y el volumen que ocupa esa misma sustancia.

Entonces, si la disolución de HNO₃ tiene una densidad de 1.32 g/mL (equivalente a 1320 g/L), donde la cantidad de masa es impura, se puede obtener la cantidad de masa de HNO₃ presente 1 L de la solución mediante el siguiente cálculo:

[tex]\frac{1320 g HNO_{3} impuro}{1 L}x \frac{70 g HNO_{3}puro}{100 g HNO_{3}impuro}= 924 \frac{g HNO_{3}puro}{L}[/tex]

Finalmente, la masa molar de HNO₃, es decir la masa presente en un mol de la sustancia, es 63 [tex]\frac{g}{mol}[/tex].

Entonces, teniendo en cuenta que la molaridad es el número de moles de soluto que están disueltos en un determinado volumen, es posible determinar la molaridad como:

[tex]\frac{924 g HNO_{3}puro}{L}* \frac{1 mol}{63 g}= 14.67 \frac{mol}{L}[/tex]

En resumen, la molaridad de la disolución es 14.67 [tex]\frac{mol}{L}[/tex]

Aprende más sobre la molaridad:

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Which of the following pairs of elements will form ionic bonds with each
other?
A. Silver (Ag) and silver (Ag)
B. Lithium (Li) and iodine (1)
C. Bromine (Br) and bromine (Br)
D. Carbon (C) and chlorine (CI)

Answers

Answer:

B. Lithium (Li) and iodine (1)

Explanation:

Ionic bond is a type of chemical bond that is formed between a metallic element and a non metallic element. The positive charge of the metallic ion is attracted to the negative charge of the non metallic ion to form an ionic bond.

According to the options given in this question, lithium and iodine will form an IONIC bond because lithium is a cation (+ve ion) while iodine is an anion (-ve).

is (H) a positive or negative value

Answers

Answer:

A chemical reaction that has a positive ΔH is said to be endothermic , while a chemical reaction that has a negative ΔH is said to be exothermic . What does it mean if the ΔH of a process is positive? It means that the system in which the chemical reaction is occurring is gaining energy.

At what approximate temperature and pressure can all three phases of water exist simultaneously?

0°C, 760 mmHg
0°C, 5 mmHg
80°C, 380 mmHg
100°C, 760 mmHg

Answers

Answer:

0⁰c , 5 mmHg

Explanation:

Because at this temperature we all know water can be in state of both solid and liquid and when pressure is decreased it can be in form of gas too

Which statement best describes how forces are important to chemistry?
A. Forces are transferred when atoms form ions.
B. Forces are released during chemical reactions.
C. Forces determine the extent of a reaction.
D. Forces hold atoms and molecules together.

Answers

Answer:

D

Explanation:

En una carrera de atletismo un deportista se muestra agotado sin fuerzas para continuar y decide abandonar la carrera ¿Que alimentos tomo antes de la carrera ?

Answers

Answer:

Los alimentos para evitar la fatiga durante una carrera son alimentos bajos en grasas y altos en carbohidratos, así como alimentos bajos en fibra como pan, mantequilla de maní, plátano, jugo de frutas sin pulpa, y beber hasta aproximadamente 600 ml de líquido aproximadamente 3 horas. antes de la carrera

La comida para comer unos días antes de la carrera incluye carnes magras, arroz, pasta y verduras con contenido de almidón.

Los alimentos que se deben evitar incluyen carne roja, alimentos con alto contenido de grasas saturadas, alimentos fritos, pasteles y salchichas.

Explanation:

Name three metals on the periodic table and their uses
PLS HELP​

Answers

The three main types of metals are
Ferrous metals
Non ferrous metals
And
Alloys

Suggest a way that a scientist could create an even more accurate model of universe expansion

Answers

Answer:

Between galaxies, retake the measurement.

Explanation:

Among both galaxies, reiterate the measurements. Instead of utilising a balloon, a scientist might create a model that shows in which everything really is and how cosmos is expanding rather than expanding. By inflating up the atmosphere to 1/2, 3/4, and full size, continue the operation.

When a compound is added to water only a few of its molecules dissociate to produce hydrogen ions. It is a...

a. strong acid.
b. weak acid.
c. strong base.
d. weak base.

Answers

b. Weak acid. I hope this helps!!
Yep, the other person that answered is correct it is a weak acid. This is because H+ ions we’re dissociated. Acids are proton donors. It was a weak acid because only a few of its molecules dissociated. Hope that explanation helps.

list from soft to hard

List the following minerals in order from softest to hardest:
apatite, calcite, talc, quartz, diamond.

Answers

Talc, apatite, calcite, quartz, diamond
I hope this helps. May you mark me brainliest?

What is the AHsol for LiF → Lit + F-? The lattice energy is -1,036 kJ/
mol, the enthalpy of hydration for Lit is -499
kJ/mol, and the enthalpy of hydration for F-is-431 kJ/mol. Use A Hooi = -A Hat + AHhydr.
0-968 kJ/mol
-106 kJ/mol
106 kJ/mol
1,966 kJ/
mol

Answers

The heat of hydration is defined as the heat absorbed or evolved when one mole of a substance undergoes hydration. The heat of solution is the enthalpy change associated with he dissolution of a solute. The lattice energy is the heat. Lattice energy is the energy released when the components of the lattice are brought together from infinity.

Hence the heat of solution for LiF → Li^+ + F- is -1966  kJ/mol

Given that;

Heat of hydration = ΔH solution – ΔH lattice energy

Where,

ΔH solution  = Heat of the solution

ΔH lattice energy = Lattice energy of the solution

The heat of solution or enthalpy of dissolution is defined as the enthalpy change associated with the dissolution of a solute in a solvent

From the formula above;

ΔH solution = Heat of hydration + ΔH lattice energy

Heat of hydration = [(-431) + (-499)] = -930 kJ/mol

ΔH solution = (-930) + (-1,036) = -1966  kJ/mol

Hence the heat of solution for LiF → Li^+ + F- is -1966  kJ/mol

https://brainly.com/question/13526282

What is Spontaneous ion

Answers

I think I found it. It was a cylinder

A compound was found to contain 90.6% lead (Pb) and 9.4% oxygen. What is the empirical formula for this compound?

Answers

Answer:

the answer is 47.9 and ik because I just had that question

The empirical formula of the compound is O₄Pb₃.

What is the empirical formula?

An Empirical system is the chemical system of a compound that offers the proportions of the elements gifted within the compound however not the real numbers or arrangement of atoms. This would be the lowest complete variety ratio of the elements within the compound.

Amount of lead (Pb) = 90.6%

⇒and amount of oxygen = 9.4%

taking the whole number ratio

o = 4

Pb = 3

∴ ⇒O: Pb=4:3

O4Pb3 answer.

Learn more about empirical formula here:-https://brainly.com/question/1603500

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QUICK PLEASE!!!

Argon is an element in the last column of the periodic table. What is its highest energy sublevel?
A.D
OB.
OC.P
DS

Answers

The highest energy sublevel of argon will be p.

Argon

Argon has an atomic number of 18.

Thus, the electron configuration of argon will be [tex]1s^2, 2 s^2, 2 p^6, 3 s^2, 3 p^6[/tex]

The ascending order of energy for the sublevel orbitals is s, p, d, and f.

Therefore, the highest energy sublevel of argon is p.

More on the energy sublevel can be found here: https://brainly.com/question/13657440

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The highest energy sublevel in the element argon is p.

What is the periodic table?

The periodic table is an arrangement of atoms according to their order of increasing atomic numbers. Now we know that there are 18 groups in the periodic table and argon belongs to group 18.

The electron configuration of argon is; 1s2 2s2 2p6 3s2 3p6. Thus, the highest energy sublevel in the element argon is p.

Learn more about argon:https://brainly.com/question/133359

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I need help with question 2

Answers

Answer:

here's the answer to your question

What is the chemical formula of potassium manganate vii

Answers

Answer:

Explanation:Visit this site for any assignments assistance

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Propane can be cracked to produce propane and hydrogen. Complete the symbol equation for the reaction.

Answers

Answer:

Explanation:

C3H8= C3H6 +H2

A chemist sets up a chemical reaction but finds that none of the reactant molecules have the required activation energy. What is the result?

A.
Products will form with less energy input.
B.
No products will be formed.
C.
The products will form too quickly.
D.
Products will convert to reactants.

Answers

Answer:

B.

No products will be formed.

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