Which of the following is an indication that a substance has undergone a chemical change?
A.
No new product has been formed.
B.
The color of the substance has not changed.
C.
The original constitute has not changed.
D.
The molecular structure has changed.

Answer:

Kb = 3.64x10⁻⁵

Explanation:

First we calculate the pOH of the solution:

Then we calculate [OH⁻]:

For a weak base solution with a relatively high concentration, we can use the following formula:

Where C is the concentration of the weak base solution (1.2 M in this case).

With the formula above we can calculate Kb:

Answer:

Conclusion.....hope this helps

Answer:

conclusion

Explanation:

Answer:

See explanation

Explanation:

1 mole of Ne occupies 22.4 L

x moles of Ne occupies 18.6 L

x = 1 mole *  18.6 L/22.4 L

x = 0.83 moles

1 mole contains 6.02 * 10^23 atoms

0.83 moles occupies  0.83 moles *  6.02 * 10^23 atoms/1 mole

= 4.9966 * 10^23 atoms = 5.0  * 10^23 atoms

the coefficient of the scientific notation answer =5.0

the exponent of the scientific notation answer = 23

significant figures are there in the answer = 5

the right most significant figure in the answer = 1

Answer: [tex]C_7H_{16}+11O_2\rightarrow 7CO_2+8H_2O[/tex]

Explanation:

According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.

The balanced chemical equation is:

[tex]C_7H_{16}+11O_2\rightarrow 7CO_2+8H_2O[/tex]

Answer:

Molal concentration of glucose = 2.64 m

Explanation:

The excersise can be solved by the formula for colligative property, elevation of boiling point.

ΔT = Kb . m . i

As glucose (C₆H₁₂O₆) is an organic compound, i = 1. (No ions generated)

ΔT = Boiling T° for solution - Boiling T° of pure solvent

Kb = Ebulloscopic constant.

We need data from acetic acid.

Boiling T° of pure solvent: 118.1°C

Kb = 3.22 °C/m

We replace data:

126.6°C - 118.1°C = 3.22°C/m . m . 1

(126.6°C - 118.1°C) / 3.22 m/°C = m

Molality = 2.64 mol/kg

Answer:

Using diverse nutrient sources can help maintain soil health. Manure and compost add organic matter as well as an array of nutrients, but using just compost or manure to meet the nitrogen needs of the crop every year can result in excessive phosphorus levels in the soil.

Answer:

I am not yet sure on my answer

I would not want to give you wrong answers

Sorry

Answer:

A molecular compound is composed of two or more non metallic elements that are held together by covalent bonds.

The two major characteristics of molecular compounds are;

1.) They are held by covalent bonds

2.) They generally have poor conductivity

Explanation:

A molecular compound is one where two or more molecules come together to form a compound. Unlike ionic compounds that combine by the transfer of electrons, molecular compounds form by sharing electrons. The pairing of the electrons is what holds the molecules together and is known as covalent bonding.

A molecular compound has various characteristics, some of which are;

- Generally low melting and boiling points

- Soft solid forms

- Low enthalpy of fusion and vaporization.

But the two major characteristics of molecular compounds are;

1.) They are held together by covalent bonds.

The elements in a molecular compound share their electrons by having their atoms bond chemically to each other.

2.) They generally have poor conductivity

Molecular compounds do not conduct electricity and heat properly. Because they are formed by sharing electrons, they usually have no free electrons left to conduct electricity.

Answer:

See Explanation

Explanation:

What Adi failed to realize is that the oily substance that was obtained from lavender consists of a mixture of substances. It is not only the required  fragrance that is present in the extract.

This experiment will not work because those other components in the mixture may be erroneously identified when they show up in the mass spectrum of the extract and may be mistaken for the fragrance in question.

Hence the experiment will not work because; if some kind of separation method is not used to identify other impurities in the oil, many other substances may be mistaken for the actual fragrance.

Answer:

Some early research suggests that subliminal messages may influence food- and diet-related thoughts and behaviors. However, other research has found that subliminal messages with weight loss cues have no effect.

Explanation:

Answer:

C

Explanation:

The oxidation number of Sulphur in SO4^2- is;

x + 4(-2) = -2

x - 8 = -2

x = -2 + 8

x = 6

Now,

the oxidation number of sulphur in H2SO3 is

2 (1) + x + 3(-2) = 0

2 + x -6 = 0

-4 + x = 0

x = 4

Hence, the oxidation number of sulphur changed from +6 to +4 which signifies  gain of two electrons as shown in option C.

answer

Avogadro's law states that, at constant temperature and pressure, the volume of a gas is directly proportional to the number of moles present. In other words, equal volumes of gases at the same pressure and temperature contain the same number of molecules - this is true regardless of their physical properties or chemical nature.

This number of molecules is

6.022

⋅

10

23

and is known as Avogadro's number,

N

A

.

Matematically, Avogadro's law can be written like this

V

n

=

c

o

n

s

t

, or, better yet,

V

1

n

1

=

V

2

n

2

.

Avogadro's law, as well as Boyle's law and Charles' law, are special cases of the ideal gas law,

P

V

=

n

R

T

. If temperature and pressure are kept constant, and knowing that

R

is of course constant, then

P

V

=

n

R

T

→

P

V

n

=

R

T

→

V

n

=

R

T

P

=

c

o

n

s

t

, which represents Avogadro's law.

The ideal gas law can also be written to incorporate

N

A

, since the number of moles are actually the number of molecules divided by Avogadro's number

P

V

=

N

N

A

⋅

R

T

, where

N

represents the number of molecules.

Answer:

27 g

Explanation:

From the question,

n = Mv...................... Equation 1

Where n = number of mole of Al₂SO₄,  M = Molarity of Al₂SO₄, v = Volume of the solution.

Given: M = 0.12 mol/L, v = 1.5 L.

Substitute these values into equation 1

n = 0.12×1.5

n = 0.18 mol

Also,

n = Mass(m)/Molar mass (m')

n = m/m'.

m = n×m'......................... Equation 2

Given: The molar mass of Al₂SO₄ = (27×2)+32+(16×4) = 150 g/mol

Substitute into equation 2

m = 0.18×150

m = 27 g

Answer:

Using Charles law of Gas

Explanation:

Answer:

B

Explanation:

Answer:   D

Explanation:  no explanation just D

Answer: energy is transferred through vibration of air particles or particles of a solid through which the sound travels.

Answer:

Sound is transmitted by vibrating a object and the waves move through particles.

Explanation:

24

N2=22.4 liters

18g=22.4 litters

18÷.75=24

Answer:

possibly because of the malleability of metals

Explanation:

In metallic bonding, electrons are delocalized and move freely among nuclei. When a force is exerted n the metal, the nuclei shift, but the bonds do not break, giving metals their characteristic malleability.

Answer:

see explanation and punch in the numbers yourself ( will be better for your test)

Explanation:

If you are given atoms you need to divide by Avogadro's number 6.022x10^23

then you will have moles of sulfur-- once you have moles multiply by the molar mass of sulfur to go from moles to grams

mm of sulfur is 32 g/mol

Mole measure the number of elementary entities of a given substance that are present in a given sample. Therefore, the grams of sulfur in  1.9x10²³ atoms of sulfur is 9.92g.

The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity of amount of substance.

Given number of atoms= 1.9x10²³atoms

we know one mole of any element contains 6.022×10²³ atoms which is also called Avogadro number

mole =given number of atoms ÷ 6.022×10²³(Avogadro number)

Substituting the values

mole=1.9x10²³÷ 6.022×10²³

mole = 0.31 mole of sulfur

Mole = given mass÷ Molar mass

Molar mass of sulfur=32g/mol

mass of sulfur =0.31 mole ×32g/mol

mass of sulfur=9.92g

Therefore, the grams of sulfur in  1.9x10²³ atoms of sulfur is 9.92g.

To know more about mole, here:

https://brainly.com/question/15209553

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Answer:

They are still the same particals just. packed together diffrently depending on what stae of matter it's in.

Explanation:

[tex]\huge{\mathbb{\tt { QUESTION↓}}}[/tex]

1. Built the first American A.C. generator.

2. Found a relationship between electricity and magnetism.

3. Associated with gas and oil.

4. First workable electric light bulb.

5. Developed the equations E=mc^2

6. Provides majority of the energy in the United States.

7. Splitting heavy atoms

8. Produces plutonium

9. Powered by falling water or stream pressure

10. Thin silicon slices

11. Using heat from the earth

[tex]\huge{\mathbb{\tt {ANSWER↓}}}[/tex]

[tex]\color{black}{\tt {1.) \: h. \: Westing \: house}}[/tex]

[tex]\color{black}{\tt {2.) \: Oersted}}[/tex]

[tex]\color{black}{\tt {3.) \: j. Gas \: and \: oil}}[/tex]

[tex]\color{black}{\tt {4.) \: c.Edison}}[/tex]

[tex]\color{black}{\tt { 5.) \: d. Einstein}}[/tex]

[tex]\color{black}{\tt {6.)i.solar cells}}[/tex]

[tex]\color{black}{\tt { 7.) \: g. fission}}[/tex]

[tex]\color{black}{\tt { 8.) Sorry \: but \: I \: don't \: know \: the \: answer}}[/tex]

[tex]\color{black}{\tt { 9.) Sorry \: but \: i \: don't \: know \: the \: answer}}[/tex]

[tex]\color{black}{\tt { 10. ) \: Sorry \: \: But \: I \: don't \: know \: the \: answer }} [/tex]

[tex]\color{black}{\tt {11.) \: b. Geothermal}}[/tex]

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Answer:

0.65moles of HCl was produced