What are chemical changes of matter?

Answer:

Explanation:

When a flask is dipped in very hot water in a large beaker , the flask expands due to heat gain . As a result , level of water in tube fitted in flask goes down .

After some time , the water inside tube also become hot so it expands  . coefficient of volume expansion of water is more than coefficient of volume expansion of glass . Hence greater expansion takes place in the volume of water . It is due to this fact that water level in tube starts rising after some time of fall .

Answer:

Here's what I get from one source.

Explanation:

[tex]\begin{array}{lc}\textbf{Source} &\textbf{Contribution \%} \\\text{Space heating }& 45\\\text{Water heating} &18\\\text{Space cooling} & 9 \\\text{Computers/Electronics} & 6 \\\text{Lighting} & 6 \\\text{Cooking} & 4 \\\text{Refrigeration} & 4 \\\text{Wet cleaning} & 3 \\\text{Other} & 5 \\\end{array}[/tex]

The pie chart is in the Figure below.

Answer:

Explanation:

The graph shows the phase diagram of water . From it , it is clear that at 100°C water remains in equilibrium with water vapour and at this temperature , the vapour pressure is equal to one  atm . So this must be boiling point of water.

At 0.7 atm pressure , boiling point must have been reduced . So when water is at 100°C , it must have been completely in vapour phase .

Now the pressure is increased to 1.4 atm . In this process of increase of pressure , the water in vapour state must have turned into liquid state as soon as the pressure increases beyond  1 atm . Beyond it its boiling point would have increased above  100°C so it can not remain in gaseous phase . At 1.4 atm , its boiling point would have increased to 110°C or so . Hence it must be in liquid phase because its temperature is below its boiling point at that pressure .

Hence water changes from gaseous phase to liquid phase when pressure changes from 0.7atm to 1.4 atm .

Explanation:

What are the two oxidation states of sulphur in sodium thiosulphate ? In thiosulphate, two sulphurs have oxidation state of -2 and +6. (as per suggestions). Sulphur bonded to three oxygen is considered to have +6 (Sulphur A) and other sulphur has -2 (Sulphur B).

Answer:

Is

Explanation:

Ammonium (NH4+) is a poly-atomic ion. ... NH4+ is not the formula of a neutral molecule, neutral ammonia is NH3. to make the ammonium ion, you add a proton (H+). Thus, Ammonium is NOT a molecular ion. You can create a molecular ion like NH3- by electron bombardment to give it a negative charge.

Hope this helps......

Answer:

50 mL of ethane, C2H6.

Explanation:

The balanced equation for the reaction is given below:

C2H6(g) + 3.5O2(g) → 2CO2(g) + 3H2O(g)

Since the reaction occurred at constant temperature and pressure, we can as well say that:

From the balanced equation above,

1 mL of C2H6 reacted with 3.5 mL of O2 to produce 2 mL of CO2 and 3 mL of H2O.

Finally, we shall determine the volume of C2H6 required to produce 100 mL of CO2.

This is illustrated below:

From the balanced equation above,

1 mL of C2H6 reacted to produce 2 mL of CO2.

Therefore XmL of C2H6 will react to produce 100 mL of CO2 i.e

XmL of C2H6 = (1 x 100)/2

XmL of C2H6 = 50 mL.

Therefore, 50 mL of ethane, C2H6 is required to produce 100 mL of carbon dioxide, CO2.

Explanation:

Hi there!!!

The organic chemistry is a branch of chemistry which deals with the study of hydrocarbons compounds. organic chemistry deals with the study of structure, properties and reactivity of carbon compounds. It is a very broad area where more than 100000 organic compounds are studied.

Hope it helps..

Answer:

Liner shape

Explanation:

Because BeCl2 has 2 bond pair and no lone pair it means it will have liner shape and 180 degree angle.

Answer:

liner compound

Explanation:

Answer:

100mL of chloromethane

Explanation:

Based on the equation:

Cl₂(g) + CH₄(g) → HCl(g) + CH₃Cl(g)

1 mole of chlorine reacts per mole of methane to produce 1 mole of HCl and 1 mole of chloromethane

Avogadro's law says that equal volumes of all gases, at the same temperature and pressure, have the same number of molecules. Using Avogadro's law we can say of the equation that:

1 mL of chlorine reacts per mL of methane to produce 1 mL of HCl and 1 mL of chloromethane

Because the system stays under constant pressure and temperature.

As 100mL of Cl₂ reacts with excess of CH₄ and 1mL of Cl₂ produce 1mL of CH₃Cl there are produced:

Answer:

The answer is option D.

Explanation:

In balancing in acidic solutions, the oxygen is accounted for by adding a water molecule or H2O on the side that needs oxygen and 2H+ molecules for every H20 molecules placed on the other side of the equation.

The H+ and H2O molecules are in the ratio 2 : 1

Hope this helps you

When balancing redox reaction equations, H20 and H^+ are used to balance the oxygen atoms.

Redox reaction equations show reactions in which electrons were lost or gained in the process. If the redox reaction involves oxygen, it is common to balance the oxygen atoms using H20 and H^+.

For instance, the equation of the reduction of MnO4^- to Mn^+ is shown below; MnO4^-(aq) + 8H^+(aq) + 5e ----> Mn^2+(aq) + 4H2O(l). We can see that hydrogen ions and water were used to balance the four oxygen atoms.

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Answer:

  2Ba₃(PO₄)₂ +6SiO₂ ⇒ P₄O₁₀ +6BaSiO₃

Explanation:

Equating coefficients, you get ...

  aBa₃(PO₄)₂ +bSiO₂ ⇒ cP₄O₁₀ +dBaSiO₃

For Ba: 3a = d

For P: 2a = 4c

For O: 8a +2b = 10c +3d

For Si: b = d

__

Expressing everything in terms of b and c, we get ...

  d = b

  a = b/3 = 2c

From the second, b = 6c, so we have ...

  a = 2c

  b = 6c

  c = c

  d = 6c

And we can write the equation with c=1 as ...

  2Ba₃(PO₄)₂ +6SiO₂ ⇒ P₄O₁₀ +6BaSiO₃

Answer:

Option (1)

Explanation:

When two or more substances are chemically combined in a fixed proportion of mass, substance formed is a compound.

Properties of a compound are different from the properties of the elements from which the compound is formed.

If Magnesium (Mg) is burned in the presence of Oxygen (O₂), Magnesium oxide (MgO) is formed.

Properties of MgO are different from Mg and O₂ because MgO is a COMPOUND.

Option (1) will be the answer.

Answer:

HeyA ❤

Let us consider the mass of oxygen as 1 g.

Mass of lead obtained from yellow oxide = 3.45 g – 0.24 g = 3.21 g

Mass of oxygen = 0.24 g

The mass of lead that combines with 0.24 g of oxygen = 3.21 g

Therefore, mass of lead that combines with 1 g of oxygen = 3.21/ 0.24 = 13.4 g

Mass of lead obtained from brown oxide = 1.227 g – 0.16 g = 1.067

Mass of oxygen = 0.16g

The mass of lead that combines with 0.16 g of oxygen = 1.067 g

Therefore, mass of lead that combines with 1 g of oxygen = 1.067/ 0.16 = 6.66 g

Now, ratio of masses of lead which combines with a fixed mass of oxygen = 13.4 : 6.66

= 2 :1

Thus, masses of lead which combine with the fixed mass of oxygen are in the ratio of (2:1) i.e. small whole numbers.

Hence, the law of multiple proportions is illustrated.

Follow meehhhh Piper ❤

Answer:

B. Because ionic compounds do not exist in discrete molecules -- they exist in crystal lattices.

Explanation:

A property of ionic compounds is that they form crystal lattice structures. Ionic compounds are crystals of many cations and anions bonded together. There is no molecule of ionic compounds because there is no single unit of the compound.

Hope this helps.

Answer:

1) 0.1077 moles

2) 137043.2 moles

3) 180.186 grams

4) 6.53×10²² molecules or formula units

5) 1.505×10²³ ions

6) 90.626 grams

7) 0.555 moles

Explanation:

1) The number of moles, n = Mass of the substance/(Molar mass of the substance)

The molar weight of PO₄⁻³ is 94.971 g/mol

The number of moles in 10.23 g of PO₄⁻³ is n =10.23/94.971 = 0.1077 moles

The number of moles in 10.23 g of PO₄⁻³ = 0.1077 moles

2) The number of molecules of Na₂CO₃ in one mole of Na₂CO₃ is given by the Avogadro's number, [tex]N_A[/tex] = 6.02 × 10²³ molecules

Therefore, the number of moles in 8.25 × 10²⁸ molecules of Na₂CO₃ is found by determining how many Avogadro's number of molecules are in 8.25 × 10²⁸ molecules of Na₂CO₃ as follows;

The number of moles in 8.25 × 10²⁸ molecules of Na₂CO₃ = (8.25 × 10²⁸)/(6.02 × 10²³) = 137043.2 moles

The number of moles in 8.25 × 10²⁸ molecules of Na₂CO₃ = 137043.2 moles

3) The molar mass of CH₂O = 30.031 g/mol

Therefore, the mass of 6 of CH₂O = 6 moles × 30.031 g/mol = 180.186 grams

The mass of 6 of CH₂O = 180.186 grams

4) The molar mass of NaCl = 58.44 g/mol

The number of moles of NaCl in 6.34 g of NaCl 6.34/58.44 = 0.1085 moles

1 formula unit of NaCl = 1 molecule of NaCl

The number of molecules in one mole of  a substance =  [tex]N_A[/tex] = 6.02 × 10²³

Therefore, the number of molecules in  0.1085 moles of NaCl = 6.02 × 10^(23) × 0.1085 = 6.53×10²² molecules or formula units

5) The number of ions per mole of any substance is give by Avogadro's number, [tex]N_A[/tex] = 6.02 × 10²³ ions,

The number of ions in 0.25 moles of Cu⁺² = 0.25×6.02 × 10²³ ions = 1.505×10²³ ions

The number of ions in 0.25 moles of Cu⁺² =  1.505×10²³ ions

6) The molar mass of CH₄ = 16.04 g/mol

The number of moles, n, in 3.4×10²⁴ = 3.4×10^(24)/(6.02×10^(23)) = 5.65 moles 5.65*16.04

The mass of 5.65 moles of CH₄ = 5.65 moles × 16.04 g/mol = 90.626 grams

The mass of 3.4×10²⁴ molecules of CH₄ = 90.626 grams

7) The density of water = 1 g/mL

The volume of the water 10 mL

The mass of the water = Volume × Density = 10 mL × 1 g/mL= 10 grams

The molar mass of water = 18.015 g/mol

The number of moles of water in 10 g  of water = mass/(Molar mass) = 10/18.015 = 0.555 moles.

Answer:

The answer is option A.

longer than visible light

Hope this helps you

Answer:

electromagnatic waves

Explanation:

Answer: I just took the test, the answer is A.

Explanation:

Answer:

Recycling and reuse of materials

Explanation:

One of the greatest problems facing the human population is the problem of solid waste disposal. The menace of solid waste disposal has led to the idea of landfills. Land fills are depressions on the earth surface prepared for the purpose of solid waste disposal.

The most important approach towards solid waste disposal is the idea of recycling of materials. A material can be collected after use and processed into the same material or serve as a precursor in another manufacturing process. This means that no waste is generated as the materials which are supposed to be disposed of as solid waste are processed into other useful materials. This will reduce the volume of solid wastes generated that may need to be disposed in a landfill.

Answer:

There are many ways to reduce the amount of trash sent to landfills: Recycle as much as possible. Limit disposable products, and use reusable ones whenever possible. Reuse, sell, or pass along old items instead of throwing them away.

Explanation: PLATO

Answer:

the answer is 5.1 1049 mol.

Answer:

Explanation:

Pure Science is a science that derives theories and predictions. Pure Science can also known as natural Science, basic science or fundamental science. Pure sciences deals with the study of natural phenomena through observation, experimentation and use of scientific methods.

Pure science is often conducted in a laboratory.The main objective of pure science is to increase information of a particular field of study and develop scientific theories.

Answer:

This is the development of the scientific theories and predictions such as in CHEMISTRY, PHYSICS and BIOLOGY.

Explanation:

It deals withe the study of Natural phenomena through observation, experiments and scientific methods.

Answer:

Hydrogen gas (H₂) + Oxygen gas (O₂) → Water (H₂O)

Explanation:

Hydrogen reacts with oxygen to form water. The reactants are hydrogen and oxygen and the product is water.

Answer:

Word Equation:

Hydrogen + Oxygen = Water

Hydrogen gas reacts with Oxygen gas to give Water.

The chemical Reaction is as follows:

    [tex]2H_{2} + O_{2}[/tex]   =>    [tex]2H_{2}O[/tex]

Answer:

The chemical weathering of feldspar produces clay minerals

Explanation:

clay minerals form in the presence of water.

Answer:

3.75 ltrs

Explanation:

The final volume of the gas is 3.8L.

Volume is the quantity of space occupied by a liquid, solid, or gas.

Using Avogadro's law.

Avogadro's Law:

V₁/n₁=V₂/n₂

Where V₁ = initial volume

            V₂ = final volume

             n₁ = initial amount of gas in moles

             n₂ = final amount of gas in moles

Avogadro's Law explains when the temperature and pressure are kept constant, volume is directly proportional to gas amount in moles, which means when the volume increases, the amount of gas also increases.

V ∝ n

V₁/n₁ = V₂/n₂

V₁ = 2.5L, V₂ = ?, n₁ = 0.30 mol, n₂ = 0.45 mol

substituting the above values in the equation,

2.5L/0.30 mol = V₂/0.45 mol

                      V₂ = 1.125/0.30 mol

                       V₂ = 3.8L

Hence, 3.8L is the final volume of the gas.

To learn more about Avogadro's law here

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Answer:

D

Explanation:

Acidity is from 1-6

Neutral 7

Base 8-14

Explanation:

It is given that,

Initial orbit of electrons, [tex]n_i=4[/tex]

Final orbit of electrons, [tex]n_f=2[/tex]

We need to find energy, wavelength and frequency of the wave.

When atom make transition from one orbit to another, the energy of wave is given by :

[tex]E=-13.6(\dfrac{1}{n_f^2}-\dfrac{1}{n_i^2})[/tex]

Putting all the values we get :

[tex]E=-13.6(\dfrac{1}{(4)^2}-\dfrac{1}{(2)^2})\\\\E=2.55\ eV[/tex]

We know that : [tex]1\ eV=1.6\times 10^{-19}\ J[/tex]

So,

[tex]E=2.55\times 1.6\times 10^{-19}\\\\E=4.08\times 10^{-19}\ J[/tex]

Energy of wave in terms of frequency is given by :

[tex]E=hf[/tex]

[tex]f=\dfrac{E}{h}\\\\f=\dfrac{4.08\times 10^{-19}}{6.63\times 10^{-34}}\\\\f=6.14\times 10^{14}\ Hz[/tex]

Also, [tex]c=f\lambda[/tex]

[tex]\lambda[/tex] is wavelength

So,

[tex]\lambda=\dfrac{c}{f}\\\\\lambda=\dfrac{3\times 10^8}{6.14\times 10^{14}}\\\\\lambda=4.88\times 10^{-7}\ m\\\\\lambda=488\ nm[/tex]

Hence, this is the required solution.

f(Hz) = 6.17 × 10¹⁴

E(J) = 4.09 × 10⁻¹⁹

E(ev) = 2.56

Answer:

67.4 % of C₉H₈O₄

Explanation:

To make titrations problems we know, that in the endpoint:

mmoles of acid = mmoles of base

mmoles = M . volume so:

mmoles of acid = 20.52 mL . 0.1121 M

mmoles of acid = mg of acid / PM (mg /mmoles)

Let's determine the PM of aspirin:

12.017 g/m . 9 + 1.00078 g/m . 8 + 15.9994 g/m . 4 = 180.1568 mg/mmol

mass (mg) = (20.52 mL . 0.1121 M) . 180.1568 mg/mmol

mass (mg) = 414.4 mg

We convert the mass to g → 414.4 mg . 1g / 1000mg = 0.4144 g

We determine the % → (0.4144 g / 0.615 g) . 100 = 67.4 %

Answer:

32. Opcion E

Explanation:

ZO₂ podemos entenderlo como dióxido de Z

1 mol de ZO₂ contiene 1 mol de Z y 2 moles de O₂ por lo que si la masa molar es de 64 g/mol, podemos plantear lo siguiente

Masa de Z + 2 masa de O = 64 g/mol

Sabemos que la masa del oxígeno es 16 g/mol

x + 2. 16 g/mol = 64 g/mol

x = 64 - 32 →  32 g/mol

La masa atómica coincide con la masa molar, por lo tanto la masa atomica de Z es 32.

Considerando la definición de masa molar, la respuesta correcta es la opción E: La masa atómica de Z debe ser 32.

La masa molar es la masa de un mol de una sustancia, la cual puede ser un elemento o un compuesto, esto es, es la relación entre la cantidad de sustancia y su masa.

En otras palabras, la masa molar es la cantidad de masa que una sustancia contiene en un mol.

En la tabla periódica, se puede encontrar la masa molar de los elementos, también llamada masa atómica o peso atómico.  

Para calcular la masa molar de un compuesto, también llamado masa o peso molecular, se debe sumar la masa molar de los elementos del compuesto multiplicado por su cantidad en el compuesto.

Entonces, en este caso, siendo la masa molar del oxígeno (O) 16, y la masa molar del compuesto ZO₂ 64, y denominando x a la masa molar de Z, entonces la masa molar del compuesto puede expresarse como:

x + 2×16= 64

Resolviendo:

x + 32= 64

x=64 -32

x=32

Finalmente, la respuesta correcta es la opción E: La masa atómica de Z debe ser 32.

Aprenda más:

Answer:

epithelial

Explanation:

nervous tissue are located only on specific areas mainly in the dermis like the parcinian to detect pressure so rashes won't be seen.muscle is located deep under the sub cutaneous layer so the symptoms can't appear.connective is also located deep in the skin eg in the eyes but epithelial tissue covers the deeper latest of the skin therefore this condition's signs can be well acknowledged I guess

Answer:

Supercontinent is a single landmass formed by the combination of many Earth's continental blocks or cratons.

Supercontinents form and split up every 400 or 500 million years and the last supercontinent was formed 300 million years ago, so it is possible that any of the modern continents will combine together to form a new supercontinent in future.

Answer:

Yes, modern continents could recombine to form a new supercontinent. Because the continents move at different rates and in different directions, it’s likely that in the future, continents will collide and join together.

Explanation: Edmentum's EXACT ANSWER SO DO NOT COPY!  Rewrite it in your own words.

Answer:

[tex]\boxed{\mathrm{view \: explanation}}[/tex]

Explanation:

This is an irreversible reaction, we cannot derive any [tex]\mathrm{K_c}[/tex] expression for it. The [tex]\mathrm{K_c}[/tex] expression can only be derived for reversible reactions and not irreversible reactions. We cannot derive the [tex]\mathrm{K_c}[/tex] expression for this reaction.