HELP!!! 30 POINTS!!!

Answer:

C

Explanation:

I just took the test

Answer:

B

Explanation:

Answer:

This question is incomplete.

Explanation:

This question is incomplete because of the absence of given mass and volume, however, the steps below will help solve the completed question. The molarity (M) of a solution is the number of moles of solute per liter of solvent. The formula is illustrated below;

Molarity = number of moles (n) / volume (in liter or dm³)

To calculate the number of moles of NaC₂H₃O₂, we say

number of moles (n) =

given or measured mass of NaC₂H₃O₂ ÷ molar mass of NaC₂H₃O₂

The volume of the solvent must be in liter (same as dm³). Thus, to convert mL to liter, we divide by 1000

The unit for Molarity is M (Molar concentration), mol/L or mol/dm³

Answer:

Temperature and Heat

Explanation:

Proportional to the average kinetic energy of the molecules in a substance.

Answer:

Explanation:

Heat required to convert ice to ice at 0⁰C

= mass x specific heat x rise in temperature

= 18 x 2.09 x 20

= 752.4 J .

heat required to convert ice at 0⁰C to water at 0⁰C

mass x latent heat of fusion

= 18 x 336

= 6048 J

Heat required to increase the temperature of water to 100⁰C

= 18 x 4.2 x 100

= 7560 J

Total heat required

7560 + 6048 + 752.4

= 14360.4 J

Answer:

V₂ = 918.1 cm³

Explanation:

Given data:

Initial volume = 640 cm³

Initial temperature = 100°C (100+273 = 373 K)

Initial pressure = 1490 mmHg (1490 /760 = 1.96 atm)

Final volume = ?

Final temperature = 273 K

Final pressure = 1 atm

Solution:

Formula:  

P₁V₁/T₁ = P₂V₂/T₂  

P₁ = Initial pressure

V₁ = Initial volume

T₁ = Initial temperature

P₂ = Final pressure

V₂ = Final volume

T₂ = Final temperature

now we will put the values in formula.

V₂ = P₁V₁ T₂/ T₁ P₂  

V₂ = 1.96 atm × 640 cm³ × 273 K / 373 K × 1 atm

V₂ = 342451.2 atm .cm³ . K / 373 K. atm

V₂ = 918.1 cm³

Answer:

F2 and Cl2 are non-polar because both contains same atom and they have same electronegativity.

ClF and NF3 have polar interactions because there is electronegativity difference between atoms.

Explanation:

The covalent bond is the chemical bond between atoms where electrons are shared, forming a molecule. Covalent bonds are established between non-metallic elements, such as hydrogen H, oxygen O and chlorine Cl. These elements have many electrons in their outermost level (valence electrons) and have a tendency to gain electrons to acquire the stability of the electronic structure of noble gas. The shared electron pair is common to the two atoms and holds them together.

Electronegativity is defined as the ability of an element to attract the electrons that link it to another element.

The covalent bond between two atoms can be polar or nonpolar.

When two atoms have different electronegativities, the one with the highest electronegativity will attract the electrons towards each other, giving rise to two opposite charges on the bond. That is, this generates that in a polar molecule there is separation between positive and negative charges. The bonds will be all the more polar the greater the difference in electronegativity between the bound atoms.

On the other hand, the non-polar covalent bond occurs between atoms of the same element or between atoms with very little electronegativity difference. It is thus characterized to molecules or bonds that do not exhibit any polarity.

A molecule is a dipole when there is an asymmetric distribution of electrons because the molecule is made up of atoms of different electronegativity. That is, dipole is formed when the molecule is polar.

So, dipole-dipole forces are forces of attraction between polar molecules. These molecules attract when the positive end of one of them is close to the negative of the other.

Given the above, F₂ and Cl₂ are non-polar molecules and ClF and NF₃ are polar molecules. Then ClF and NF₃ have polar interactions (dipole-dipole forces). -Brainly user

Answer : A

Explanation

B- conduction

c - convection

D heat transfer

Answer:

d

Explanation:

Answer:

Opaque Material

Answer:

A ground glass is translucent as it allows only partial light to pass through it and forms light shadows

Answer:

what the answer is dream but what

Explanation:

Answer:

They have the same number of valence electrons.

Explanation:

As a rule of thumb, elements with the same chemical properties must have the same number of valence electrons. This is why elements in the same group have similar chemical properties.

Answer:

167 mL.

Explanation:

We'll begin by calculating the number of moles in 45 g of aluminum (Al). This can be obtained as follow:

Mass of Al = 45 g

Molar mass of Al = 27 g/mol

Mole of Al =?

Mole = mass /Molar mass

Mole of Al = 45/27

Mole of Al = 1.67 moles

Next, the balanced equation for the reaction. This is given below:

2Al + 3H2SO4 → Al2(SO4)3 + 3H2

From the balanced equation above,

2 moles of Al reacted with 3 moles of H2SO4.

Next, we shall determine the number of mole of H2SO4 needed to react with 45 g (i.e 1.67 moles) of Al. This can be obtained as:

From the balanced equation above,

2 moles of Al reacted with 3 moles of H2SO4.

Therefore, 1.67 moles of Al will react with = (1.67 × 3)/2 = 2.505 moles of H2SO4.

Thus 2.505 moles of H2SO4 is needed for the reaction.

Next, we shall determine the volume of H2SO4 needed for the reaction. This can be obtained as follow:

Molarity of H2SO4 = 15.0 M

Mole of H2SO4 = 2.505 moles

Volume =?

Molarity = mole /Volume

15 = 2.505 / volume

Cross multiply

15 × volume = 2.505

Divide both side by 15

Volume = 2.505/15

Volume = 0.167 L

Finally, we shall convert 0.167 L to mL. This can be obtained as follow:

1 L = 1000 mL

Therefore,

0.167 L = 0.167 L × 1000 mL / 1 L

0.167 L = 167 mL

Thus, 0.167 L is equivalent to 167 mL.

Therefore, 167 mL H2SO4 is needed for the reaction.

Answer:

48.0g is the specific gravity of liquid sample with a mass of 35.0g and a volume of 14.00 mL

Answer:

Final pressure =P₂ = 15.13 psi

Explanation:

Given data:

Initial volume = 0.250 L

Initial pressure = 14.7 psi

Initial temperature = -80.0°C (-80.0 +273 = 193 K)

Final volume = 0.375 L

Final temperature = 25.0°C (25+273 =298 k)

Final pressure = ?

Solution:

P₁V₁/T₁ = P₂V₂/T₂  

P₁ = Initial pressure

V₁ = Initial volume

T₁ = Initial temperature

P₂ = Final pressure

V₂ = Final volume

T₂ = Final temperature

Now we will put the values in formula.

P₂ = P₁V₁ T₂/ T₁ V₂  

P₂ = 14.7 psi × 0.250 L × 298 K / 193 K × 0.375 L  

P₂ = 1095.15 psi .L. K / 72.375 K.L

P₂ = 15.13 psi

Answer:

46.32 mL

Explanation:

We'll begin by writing the balanced equation for the reaction. This is illustrated below:

2HNO₃ + Ca(OH)₂ —> Ca(NO₃)₂ + 2H₂O

From the balanced equation above,

The following data were obtained:

Mole ratio of the acid, HNO₃ (nA) = 2

Mole ratio of the base, Ca(OH)₂ (nB) = 1

Next, we shall write out the data obtained from the question. This includes:

Molarity of the acid, HNO₃ (Ma) = 0.181 M

Volume of the base, Ca(OH)₂ (Vb) = 25.1 mL

Molarity of the base, Ca(OH)₂ (Mb) = 0.167 M

Volume of the acid, HNO₃ (Va) =?

Finally, we shall determine the volume of the acid, HNO₃ as shown below:

MaVa/ MbVb = nA/nB

0.181 × Va / 0.167 × 25.1 = 2/1

0.181 × Va / 4.1917 = 2

Cross multiply

0.181 × Va = 4.1917 × 2

0.181 × Va = 8.3834

Divide both side by 0.181

Va = 8.3834 / 0.181

Va = 46.32 mL

Therefore, the nitric acid, HNO₃ required for the reaction is 46.32 mL

Answer:

Explanation:

In carbon monoxide ,

2.5 g of carbon reacts with 3.33 g of oxygen

In unknown gas X ,

.75 g of carbon reacts with 2 .00 g of oxygen

2.5 g of carbon will react with 6.66 g of oxygen in X gas .

Ratio of oxygen in two compounds , reacting with same mass of carbon

= 3.33 : 6.66

= 1 : 2 , a simple ratio

It follows law of multiple proportions .

First gas is CO or carbon monoxide

X gas is CO₂ or carbon dioxide .

In this gas , ratio of oxygen reacting with same amount of carbon is doubled .

Answer:

heat, electrical, mechanical, nuclear,sound

Explanation:

The power plant is mechanicalised so it produce heat which is in form of electrical and then we start hearing sound

Answer:

I thin its B im not sure though

Explanation:

The puppies from the same set of parents have different color noses because the pink-nosed puppy and the black nosed puppy inherited different combinations of the genes for nose color from their parents. Thus, the correct option is B.

A gene is the unit of inheritance which is made up of DNA (deoxyribonucleic acid). Every person receives two copies or alleles of each gene which is inherited from each of the two parent.

Genes are made up of DNA, so each of the chromosome contains many different genes. Genes carry the information which determines the traits or characteristics that are passed on to their offspring or inherited from the parents.

The puppies from the same set of parents have different colored noses because pink-nosed puppy and the black nosed puppy inherited different combinations of the genes for nose color from their parents.

Therefore, the correct option is B.

Learn more about Inheritance here:

https://brainly.com/question/14930526

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Answer:

Explanation:

2Al(s) + 3 I₂(s)   →    2 Al⁺³    +     6 I⁻

Aluminium is oxidised and iodine is reduced .

so cell potential = Ereduction - Eoxidation

Al⁺³ + 3e = Al          -  1.66 V

I₂ + 2 e = 2 I⁻             0.54 V

=  .54 - ( - 1.66 )

= 1.66 + .54

= 2.2  V

The overall standard cell potential for the given cell that employs the overall cell reaction is; E°_cell = 2.20 V

We are given the cell reaction;

2Al (s) + 3I₂ (s) → 2Al⁺³ + 6I⁻

We are given reduction potential as;

Al⁺³(aq) + 3e⁻ → Al(s) ;E°_red = -1.66 V

However, the standard reduction potential for the reverse of the oxidation reaction is;

Al → Al⁺³(aq) + 3e⁻ ;E°_ox = 1.66 V

We are also given;

I₂ + 2e⁻ = 2I⁻ ;E°_red = 0.54 V

To get  overall standard cell potential, we will add the cell potentials to get;

E°_cell = E°_ox + E°_red

E°_cell = 1.66 + 0.54

E°_cell = 2.20 V

Read more at; https://brainly.com/question/13984052

Answer:

2H⁺(aq) + 2OH⁻(aq)  --> 2H2O(l)

Explanation:

2HBr(aq)+Ba(OH)2(aq)⟶2H2O(l)+BaBr2(aq)

We break the compounds into ions. Only compounds in the aqueous form can be turned into ions.

The ionic equation is given as;

2H⁺(aq)  +  2Br⁻(aq)  + Ba²⁺(aq) + 2OH⁻(aq)   --> 2H2O(l)  +  Ba²⁺(aq)  + 2Br⁻(aq)

Upon eliminating the spectator ions; The net equation is given as;

2H⁺(aq) + 2OH⁻(aq)  --> 2H2O(l)

The value of x​ : 2

Semi-normal Hydrochloric acid solution = 0.5 N = 0.5 M

for titration :

M₁V₁n₁=M₂V₂n₂(1=HCl,2=Na₂CO₃)

[tex]\tt 0.5\times 20\times 1=M_2\times V_2\times 2\\\\M_2V_2=5~mlmol=5.10^{-3}mol[/tex]

[tex]\tt MW=\dfrac{mass}{mol}=\dfrac{0.715}{5.10^{-3}}=143~g/mol[/tex]

MW Na₂CO₃.xH₂O=143

MW Na₂CO₃.xH₂O = MW Na₂CO₃+ MW xH₂O = 143

MW Na₂CO₃ = 106 g/mol

MW xH₂O = 18x

Equation :

[tex]\tt 106+18x=143\\\\18x=37\\\\x=\dfrac{37}{18}=2.056\approx 2[/tex]

Answer:

1.B

2.A

3. B

Explanation:

1. A chemical bond is the physical phenomenon of chemical substances being held together by attraction of atoms to each other through sharing

2. so 2 is electrons of one atom are transferred permanently to another atom.meaning the answer is A

3. is When atoms combine by forming covalent bonds, the resulting collection of atoms is called a molecule. We can therefore say that a molecule is the simplest unit of a covalent compound.

A chemical bond is an attraction between two atoms.

A ionic bond is A bond formed when atoms transfer electrons.

Answer:hi

Explanation:

Answer:

nomenclature of alkanes

Explination:

Substituent Formula Number of C Atoms Name of Substituent

CH3                                   1                                         methyl–

CH3CH2                                  2                              ethyl–

CH3CH2CH2                           3                    propyl–

CH3CH2CH2CH2                       4               butyl–

CH3CH2CH2CH2CH2                     5                  pentyl–

and so forth                      and so forth     and so forth

Try this it helped me allot,

Alkenes and alkynes are named in a similar fashion. The biggest difference is that when identifying the longest carbon chain, it must contain the C–C double or triple bond. Furthermore, when numbering the main chain, the double or triple bond gets the lowest possible number. This means that there may be longer or higher-numbered substituents than would be allowed if the molecule were an alkane. For example, this molecule is 2,4-dimethylhept-3-ene (note the number and the hyphens that indicate the position of the double bond).

2,4-dimethylhept-3-ene

or two one carbonsubstituents on the second and third C atoms

its not 3-methylheptane.

Answer:

411.6 g

Explanation:

The equation for the decomposition of potassium chlorate to produce oxygen is given as;

2KClO3 --> 2KCl + 3O2

From the stochiometry of the reaction 2 mole of KClO3 produces 3 mol of O2

At STP,

1 mol = 22.4L

3 mol = x

x = 67.2L

2 mole of KClO3 produces 67.2L of O2

How many moles would produce 113L?

2 = 67.2

x = 113

x = 3.36 moles

Moles can be converted to mass using;

Mass = moles * Molar mass

Mass = 3,36 * 122.5 g/mol

Mass = 411.6 g

Answer:

option B is correct

Explanation:

momentum(p)=mv

mass= m=4 kg

velocity=v=1.5 m/s

P=4kg*1.5 m/s=6.0 kg.m/s

so option B is correct

Explanation:

The gamma ray photons make their arduous journey to the surface of the Sun, they are continuously absorbed by the solar plasma and re-emitted to lower frequencies. ... By the time they get to the surface, their frequencies are mostly only within the IR/visible light/UV spectrum. Nov28,2020

Answer:

[tex]\Delta _fH_{NH_3}=-66\frac{kJ}{mol}[/tex]

Explanation:

Hello!

In this case, since the study of the bond energy allows us to compute the enthalpies of some reactions, for this combination reaction by which ammonia is yielded, we understand the enthalpy of reaction equals the enthalpy of formation of ammonia, and, in terms of the bonds energy we can write:

[tex]\Delta _fH_{NH_3}=Delta _rH=\Sigma \Delta H(bonds \ broken)-\Sigma \Delta H(bonds \ formed)[/tex]

Whereas the bonds enthalpy of those bonds that get broken cover the N≡N and the three H-H bonds at the reactants side and the enthalpy of those bonds that are formed cover the six N-H bonds at the products; which means we obtain:

[tex]\Delta _fH_{NH_3}=942\frac{kJ}{mol} +3*436\frac{kJ}{mol}-6*386\frac{kJ}{mol}\\\\\Delta _fH_{NH_3}=-66\frac{kJ}{mol}[/tex]

Which differs from the theoretical value that is -46 kJ/mol.

Best regards!