I need help with this chemistry question talking about pure substances and mixtures?

Answer:

An ion is a charged atom or molecule. It is charged because the number of electrons do not equal the number of protons in the atom or molecule. ... When an atom is attracted to another atom because it has an unequal number of electrons and protons, the atom is called an ION.

Explanation:

Answer:

when they have eight valence electrons.

Explanation:

When atoms do not have a full valence shell, the atoms are more likely to react with other and vice versa.

Answer:

When they have a full shell of electrons

Explanation:

and or eight valence electrons

Answer:

Why the gravitational force is greater near the poles and less at equator?

Gravitational force of Earth is minimum at equator because the centrifugal force at the equator is maximum.

Centrifugal force is an outward force exerted on a body revolving in a circular path, to mantain its state of motion.

Explanation:

Here Earth revolves around its axis and the same forces act on it to enable its revolution.

Gravitational force at the equator is less because Centrifugal force, which is also acting at the equator cancels out the Gravitational force to an extent. Whereas at poles, there is no such effect of centrifugal force because earth is sphere (bulged at center; flat at poles )and hence gravitational force is maximum at poles.

The other reason is distance from any place on equator to centre of earth is more than at poles. Because Earth is bulged at centre and flat at poles. Since Gravitational force is given by

F= GMm/ r^2 ; r is the distance between two bodies.

Answer:

True.

Explanation:

The mass number of an atom can be calculated using no of protons and the no of neutrons.

Mass number = no of protons + no of neutrons

We can rearrange the above formula to find the no of neutrons as follows :

no of neutrons = Mass number - no of protons

or

Neutrons = Mass - protons.

Hence, the given statement is true.

Answer: 21.5kg in grams is 21,500 grams

21.5kg in mg is 215,000,00

Explanation:

Answer:

pH = 11.60

Explanation:

When we add a base, we are increasing [OH⁻], so the pH will be totally basic.

pH of water = 7

Basic pH > 7

We are adding 2 M . 1 mL = 2 mmoles

2 mmoles of OH⁻ are contained in 501 mL of total volume.

[OH⁻] = 2 mmol / 501 mL =  3.99×10⁻³ M

- log 3.99×10⁻³ M = 2.39 → pOH

pH = 14 - pOH → 11.61

Water equilibrium

2H₂O  ⇄  H₃O⁺   +  OH⁻          Kw = 1×10⁻¹⁴

NaOH  →  Na⁺   +  OH⁻

Answer:

4 mole hydrozen and 2 mole oxyzen

Explanation:

Answer: E = 1.55 ⋅ 10 − 19 J

Explanation:  

The energy transition will be equal to  1.55 ⋅ 10 − 1 J .  

So, you know your energy levels to be n = 5 and n = 3. Rydberg's equation will allow you calculate the wavelength of the photon emitted by the electron during this transition

1 λ  = R ⋅ ( 1 n 2 final  − 1 n 2 initial  ) , where λ - the wavelength of the emitted photon; R

- Rydberg's constant -  1.0974 ⋅ 10 7 m − 1 ; n final - the final energy level - in your case equal to 3; n initial - the initial energy level - in your case equal to 5. So, you've got all you need to solve for  λ , so 1 λ  =

1.0974 ⋅10  7 m − 1 ⋅ (....     −152    

)

1

λ

=

0.07804

⋅

10

7

m

−

1

⇒

λ

=

1.28

⋅

10

−

6

m

Since  

E

=

h

c

λ

, to calculate for the energy of this transition you'll have to multiply Rydberg's equation by  

h

⋅

c

, where

h

- Planck's constant -  

6.626

⋅

10

−

34

J

⋅

s

c

- the speed of light -  

299,792,458 m/s

So, the transition energy for your particular transition (which is part of the Paschen Series) is  

E

=

6.626

⋅

10

−

34

J

⋅

s

⋅

299,792,458

m/s

1.28

⋅

10

−

6

m

E

=

1.55

⋅

10

−

19

J

Answer:

lack of snow in the mountains makes drought cycles worse because mountains are a natural part of the water cycle.

Explanation:

Mountains play a critical part In the water cycle by capturing moisture in the air and it precipitates as snow and when it does this the snow will melt in the warmer seasons and flow down stream then following the rest of the water cycle if we didn't have this then the streams would run less and it would greatly disrupt the water cycle.

Answer:

AgCl + NaNO3 would be the products of the reaction between sodium chloride and silver nitrate.

The stoichiometry of this reaction is written below, and it is because for this reaction to be fulfilled the products have to be in equilibrium with the reactants, since the mass in the reaction is conserved and must be balanced in the amount of molecules that they react to each other.

Explanation:

NaCl + AgNO3 -------------- AgCl + NaNO3

Answer:

ΔH = -470.4kJ

Explanation:

It is possible to sum 2 or more reactions to obtain the ΔH of the reaction you want to study (Hess's law). Using the reactions:

1. CaC2(s) + 2H2O(l) → C2H2(g) + Ca(OH)2(s)ΔH = −414kJ

2. 6C2H2(g) + 3CO2(g) + 4H2O(g) → 5CH2CHCO2H(g)ΔH = 132kJ

6 times the reaction 1.

6CaC2(s) + 12H2O(l) → 6C2H2(g) + 6Ca(OH)2(s)ΔH = −414kJ*6 = -2484kJ

This reaction + 2:

6CaC2(s) + 3CO2(g) + 16H2O(l) →  + 6Ca(OH)2(s) + 5CH2CHCO2H(g) ΔH = -2484kJ + 132kJ = -2352kJ

As we want to calculate the net change enthalpy in the formation of just 1 mole of acrylic acid we need to divide this last reaction in 5:

6/5CaC2(s) + 3/5CO2(g) + 16/5H2O(l) →  + 6/5Ca(OH)2(s) + CH2CHCO2H(g) ΔH = -2352kJ / 5

Given :

A 250 ml beaker weighs 13.473 g .

The same beaker plus 2.2 ml of water weighs 15.346 g.

To Find :

How much does the 2.2 ml of water, alone, weigh .

Solution :

Now, mass of water is given by :

[tex]\text{Mass of water alone = Total mass - Mass of beaker alone}\\\\Mass =15.346-13.473\ g\\\\Mass =1.873\ g[/tex]

Therefore , mass of 2.2 ml of water alone is 1.873 g .

Hence , this is the required solution .

Given :

Concentration of NaCl , [tex]c=0.85 \%[/tex] .

To Find :

Th amount of solid NaCl must be weighed out on the balance to prepare a bottle full containing 3500 ml .

Solution :

Concentration of NaCl is 0.85 % .

It means , 0.85 gm of NaCl in 100 ml of water .

So , amount of solid NaCl required to prepare 3500 ml solution is :

[tex]x=\dfrac{3500\times 0.85}{100}\ gm\\\\x=29.75\ gm[/tex]

Therefore , amount of solid NaCl required is 29.75 gm .

Hence , this is the required solution .

Answer:

COBALT

Explanation:

CO BALT COBALT

Answer:

1 gram

Explanation:

1 gram= weight of 1 cubic centimeter of pure water at temperature 4°C = 1000 milligrams = 0.001 kilogram

3 tanks of gas->32*3->96 gallons in total.

96*3.29->315.84

3 sig. figs. -> $315

Answer:

72574.8

Explanation:

Thats what google says

Answer:

Halogenation

Explanation:

Halogenation is a type of substitution reaction in which a hydrogen atom is replaced by a halogen atom in a molecule.

The molecule looses its hydrogen atom as the halogen is introduced into the molecule. This sort of reaction is very common in organic chemistry. Many hydrocarbons can be halogenated in the presence of light.

Answer:

C. -CH3

Explanation:

The pKa (acid dissociation constant) of an amino acid residue is primarily influenced by the functional groups attached to the adjacent end of the amino acid chain. The acidity of a functional group depends on how electronegative the functional group is. In the given functional groups' list, the functional group with the least influence on the pKa of the amino acid is the alkyl substituent (-CH3), because they have the least electron-withdrawing capacity.

Answer:

METHYL PENTENE or 2-METHYL PENT-2-ENE

Explanation:

The number 2 carbon carries the methyl group and the double bone is on the 2 carbon as well.

The chemical structure of the compound has been attached.

I hope this is what you were looking for.

Answer:

C→O, O→Cl, O→F, C→N, C←Li, S ←H, S→Cl

Explanation:

The general convention for indicating polarity in molecules is that of showing the direction of polarity from the positive to the negative part of the bond. This is indicated in the answer by arrows that show the direction of the dipole.

The negative end of the dipole must be the more electronegative element while the positive end of the dipole is the less electronegative element, hence the answer shown above.

The delta notation, indicating the polarity of for the presented covalent bonds are:

Polar bonds are those in which atoms have different electronegativities.

The delta notation is used to indicate the direction of the polarity.

The atom with the greater electronegativity acquires a partial negative charge (goes with the symbol δ-), while the atom with the lesser electronegativity acquires a partial positive charge (goes with the symbol δ+).

Let's consider the following elements with their electronegativities.

The delta notation for the presented bonds are:

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Answer:

Explanation:

A spontaneous chemical process is one in which product formation is favoured under the specified conditions. A spontaneous process yields the product without an external input of energy.

A spontaneous reaction will always occur when ∆H is negative and ∆S is positive. These are the signs of enthalpy and and entropy change that gives rise to a spontaneous chemical process at all temperatures. Recall that a spontaneous process is one in which ∆G<0.

Answer:

8.76M

Explanation:

Given that

Mass from the density = 1141g

According to the given situation the computation of molarity of the solution is shown below:-

we will took HCL solution which is 1000mL

HCl = 28% by mass

So,

Mass of HCl in 1-litre solution is

[tex]= \frac{28}{100} \times 1141[/tex]

Which gives the result of molar mass HCI is

= 319.48g /mol

Now,

Molarity is

[tex]= \frac{319.48}{36.45}[/tex]

Which gives results of molarity is

= 8.76M

Answer:

triple beam balance

Explanation:

The tool that can be used to measure mass is a triple beam balance. Therefore, the correct option is option B.

A graduated cylinder is used to determine a liquid's volume. A mercury thermometer is used to measure temperature. Weight is calculated on a bathroom scale and is a force rather than a mass. A typical scientific tool for calculating an object's mass is a triple beam balance.

It is composed of three beams with moveable weights that enable precise mass balancing and a pan on one end where the thing to be measured is placed. By comparing the placement of the weights on the beams to the appropriate scale, the mass of the object can be ascertained.

Therefore, the correct option is option B.

To know more about mass, here:

https://brainly.com/question/11954533

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Answer:

In chemistry, neutralization or neutralisation (see spelling differences) is a chemical reaction in which acid and a base react quantitatively with each other. In a reaction in water, neutralization results in there being no excess of hydrogen or hydroxide ions present in the solution.

Answer:

A neutralization reaction is when an acid and a base react to form water and a salt and involves the combination of H+ ions and OH- ions to generate water. The neutralization of a strong acid and strong base has a pH equal to 7

Explanation:

Answer:

H2O > CH3OH > CH3CH2NH2 > CH3OCH3 > CH3CH2CH3

Explanation:

Hydrogen bonding exists in molecules in which hydrogen is bonded to a highly electronegative element such as fluorine, chlorine, oxygen, sulphur, nitrogen etc.

Water has the highest degree of hydrogen bonding among the listed substances hence its very high boiling point, stemming from intermolecular hydrogen bonding. CH3CH2NH2 has a lesser degree of hydrogen bonding because nitrogen is less electronegative than oxygen.

Alcohols show significant hydrogen bonding in solution, the same applied to amines. However, ethers do not form hydrogen bonds with each other but they can form hydrogen bonds with other molecules such as alcohols and amines. Alkanes do not form hydrogen bonds at all.

Answer:

0.092 %

Explanation:

The equation of the reaction can be computed as :

[tex]12CO_2_{(g)} + 11H_2O_{(l)} \to C_{12}H_{22}O_{11} + 12O_{2_(g)}[/tex]

[tex]\Delta H = 5645 \ kJ[/tex]

recall that; the number of moles = [tex]\dfrac{mass}{molar \ mass}[/tex]

By applying the method of enthalpy of combustion for sucrose at the same time changing the time from hours to seconds, we can determine the total energy output.

i.e

[tex]=\dfrac{0.20g \ of \ sucrose }{m^2 \ 3600 \ s}\times \dfrac{1 \ mol}{342.34 \ g}\times 5.645 kJ/mol[/tex]

[tex]= 9.16 \times 10^{-4} \ kJ/m^2 s[/tex]

Given that the sun supplies about 1.0 kilowatt, to KJ/m² s, we have:

[tex]1.0 \dfrac{kW}{m^2 }= 1.0 \dfrac{kJ}{m^2 s}[/tex]

Finally, the percentage of sunlight used to produce sucrose :

= [tex]\dfrac{9.16 \times 10^{-4} \ kJ/m^2 \ s}{1.0 \ kJ/m^2 . s} \times 100\%[/tex]

= 0.092 %