What is the difference between a physical change and a chemical change. Give an example of each.

Answer:

[tex]4.67\times 10^{-4}[/tex]

Explanation:

Given that,

The pH of a certain orange juice is 3.33.

We need to find the +ion concentration.

We know that,

[tex]pH=-log[H^+][/tex]

So,

[tex]3.33=-log[H^+]\\\\\[H^+=10^{-3.33}\\\\=4.67\times 10^{-4}[/tex]

So, the +ion concentraion is equal to [tex]4.67\times 10^{-4}[/tex].

The answer ( 13 and 8 )

x²=5²+12²

x²=25+144

x²=169

x=13

x²=5²+6²

x²=25+36

x²=61

x=7.8

x=8

Answer:

Explanation:

An electrophilic addition reaction occurs when an electrophile attacks a substrate, with the end result being the inclusion of one or many comparatively straightforward molecules along with multiple bonds.

In the given question, the hydrogen bromide provides the electrophile while the bromide is the nucleophile. The mechanism proceeds with the attack of the electrophile on the carbon, followed by deprotonation. This process is continued with a formation of carbocation and the bromide(nucleophile) finally bonds to the carbocation to form a stable product.

The first diagram showcases the possible various starting molecules for the synthesis while the second diagram illustrates their mechanism.

Answer:

Explanation:

When an electron moves from a lower energy level to a higher energy level, energy is absorbed by the atom. When an electron moves from a higher to a lower energy level, energy is released and photon is emitted.

this emitted photon is depicted as a small wave-packet being expelled by the atom in a well-defined direction.

Answer:

physical change because the gaseous water is chemically the same as the liquid

Explanation:

Matter can be defined as anything that has mass and occupies space. Any physical object that is found on earth is typically composed of matter. Matter are known to be made up of atoms and as a result has the property of existing in states.

Generally, matter exists in three (3) distinct or classical phases and these are; solid, liquid and gas.

A physical change can be defined as a type of change that only affects the physical form of a chemical substance (matter) without having any effect on its chemical properties. Thus, a physical change would only affect the physical appearance and properties of a chemical substance (matter) but not its chemical properties.

This ultimately implies that, a physical change result in a change of matter from one form or phase (liquid, solid or gas) to another without a corresponding change in chemical composition.

Hence, the boiling of water is considered to be a physical change because the gaseous water is chemically the same as the liquid i.e there isn't any changes in chemical composition of water when boiling.

Explanation:

For preparing lyophobic sol, the substance in bulk is broken down into particles of colloidal dimensions (Dispersion) or aggregating smaller particles into particles of colloidal dimensions (condensation).

Answer:

bleh

Explanation:

Answer:

Magnesium reacts with dilute hydrochloric acid in a conical flask which is ... One student can add the magnesium ribbon to the acid and stopper the flask, ... 50 cm3 of 1M hydrochloric acid is a six-fold excess of acid.

Answer:

A 1 liter volumetric flask should be used.

Explanation:

First we convert 166.00 g of KI into moles, using its molar mass:

Molar mass of KI = Molar mass of K + Molar mass of I = 166 g/mol

Then we calculate the required volume, using the definition of molarity:

Liters = moles / molarity

Answer:

MgO

Explanation:

Answer:

Reactions involving the replacement of one atom or group of atoms. - Substitution reaction

Reactions involving removal of two atoms or groups from a molecule - Elimination reaction

Products show increased bond order between two adjacent atoms - Elimination reaction

Reactant requires presence of a π bond - Addition reaction

Product is the structural isomer of the reactant - Rearrangement reaction

Explanation:

When an atom or a group of atoms is replaced by another in a reaction, then such is a substitution reaction. A typical example is the halogenation of alkanes.

A reaction involving the removal of two atoms or groups from a molecule resulting in increased bond order of products is called an elimination reaction. A typical example of such is dehydrohalogenation of alkyl halides.

Any reaction that involves a pi bond is an addition reaction because a molecule is added across the pi bond. A typical example is hydrogenation of alkenes.

Rearrangement reactions yield isomers of a molecule. Rearrangement may involve alkyl or hydride shifts in molecules.

Reactions involving the replacement of one atom or group of atoms is substitution reaction, reactions involving removal of two atoms or groups from a molecule and products show increased bond order between two adjacent atoms is elimination reaction, reactant requires presence of a π bond in addition reaction and product is the structural isomer of the reactant is rearrangement reaction.

Chemical reactions are those reactions in which reactants undergoes through a variety of changes for the formation of new product.

Hence, classification of above points are done according to their characteristics.

To know more about chemical reactions, visit the below link:

https://brainly.com/question/26018275

Answer:

Gains

Explanation:

It gets more electrons

Answer: The mass of [tex](NH_4)_2SO_4[/tex] produced is 9910.5 g

Explanation:

Molarity is calculated by using the equation:

[tex]\text{Molarity}=\frac{\text{Moles}}{\text{Volume}}[/tex] ......(1)  

Molarity of [tex]H_2SO_4[/tex] = 3.0 M

Volume of solution = 25.0 L

Putting values in equation 1, we get:

[tex]\text{Moles of }H_2SO_4=(3.0mol/L\times 25.0L)=75mol[/tex]

The ideal gas equation is given as:

[tex]PV=nRT[/tex] .......(2)

where,

P = pressure of the gas = 0.68 atm

V = volume of gas = [tex]3.1\times 10^3L[/tex]

n = number of moles of gas = ? moles

R = Gas constant = 0.0821 L.atm/mol.K

T = temperature of the gas = 298 K

Putting values in equation 2, we get:

[tex]0.68atm\times 3.1\times 10^3L=n\times 0.0821L.atm/mol.K\times 298K\\\\n=\frac{0.68\times 3.1\times 10^3}{0.0821\times 298}=86.16mol[/tex]

For the given chemical equation:

[tex]NH_3(g)+H_2SO_4(aq)\rightarrow (NH_4)_2SO_4(aq)[/tex]

By stoichiometry of the reaction:

If 1 mole of [tex]H_2SO_4[/tex] reacts with 1 mole of [tex]NH_3[/tex]

So, 75 moles of [tex]H_2SO_4[/tex] will react with = [tex]\frac{1}{1}\times 75=75mol[/tex] of [tex]NH_3[/tex]

As the given amount of [tex]NH_3[/tex] is more than the required amount. Thus, it is present in excess and is considered as an excess reagent

Thus, [tex]H_2SO_4[/tex] is considered a limiting reagent because it limits the formation of the product.

By the stoichiometry of the reaction:

If 1 mole of [tex]H_2SO_4[/tex] produces 1 mole of [tex](NH_4)_2SO_4[/tex]

So, 75 moles of [tex]H_2SO_4[/tex] will produce = [tex]\frac{1}{1}\times 75=75mol[/tex] of [tex](NH_4)_2SO_4[/tex]

The number of moles is defined as the ratio of the mass of a substance to its molar mass. The equation used is:

[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex]

We know, molar mass of [tex](NH_4)_2SO_4[/tex] = 132.14 g/mol

Putting values in above equation, we get:

[tex]\text{Mass of }(NH_4)_2SO_4=(75mol\times 132.14g/mol)=9910.5g[/tex]

Hence, the mass of [tex](NH_4)_2SO_4[/tex] produced is 9910.5 g

Answer: The molarity of NaCl solution is 0.0489 M

Explanation:

Molarity is defined as the amount of solute expressed in the number of moles present per liter of solution. The units of molarity are mol/L. The formula used to calculate molarity:

[tex]\text{Molarity of solution}=\frac{\text{Given mass of solute}\times 1000}{\text{Molar mass of solute}\times \text{Volume of solution (mL)}}[/tex] .....(1)

We are given:

Given mass of NaCl = 0.8 g

Molar mass of NaCl = 58.44 g/mol

Volume of the solution = 280 mL

Putting values in equation 1, we get:

[tex]\text{Molarity of solution}=\frac{0.8\times 1000}{58.44\times 280}\\\\\text{Molarity of solution}=0.0489M[/tex]

Hence, the molarity of NaCl solution is 0.0489 M

Answer:

43.5

Explanation:

Hope that helps

Answer:

Yard . I hope this helped:))

Answer:

Explanation:

[H+] = 0.1x0.03x2 + 0.2x0.03 = 0.012 mol

[OH-] = 0.001x0.05x2 = 0.0001 mol

=> [H+] dư = 0.012 - 0.0001 =0.0119 mol

pH = -log[H+] = 1.92

Answer:

NaCl

Explanation:

[tex]na + cl > nacl[/tex]

This is also a salt

Answer:

See explanation.

Explanation:

Hello there!

In this case, since this problem  is about gas laws, more specifically about the Gay-Lussac's one since the volume is said to be constant, we can use the following equation for its solution for the final pressure, P2:

[tex]\frac{P_2}{T_2} = \frac{P_1}{T_1}[/tex]

[tex]P_2= \frac{P_1T_2}{T_1}\\\\P_2 =\frac{12.0atm*450K}{300K}\\\\P_2= 18.0atm[/tex]

Thus, we fill in the table as follows:

                           Initial        Final

Pressure           12.0 atm     18.0 atm

Volume                4.0 L         4.0 L

Temperature      300K         450K

Regards!

Answer:

The mole is defined as a collection of 6.022 × 1023 particles.

The atomic mass given on a periodic table that is given in grams is the mass of

one mole (6.022 × 1023 particles) of that element

Explanation:

Answer:

[tex]m=88.02g[/tex]

Explanation:

Hello there!

In this case, for this ideal gas law problem, it turns out necessary for us to remember that one mole of any gas is contained in 22.4 L at STP and therefore, we can use the following ratio to calculate the moles in 44.8 L of CO2:

[tex]\frac{1mol}{22.4L} =\frac{x}{44.8L}\\\\x= \frac{1mol*44.8L}{22.4L}=2mol[/tex]

Finally, since the molar mass of CO2 is 44.01 g/mol, we calculate the mass as follows:

[tex]m=2mol*\frac{44.01g}{1mol}\\\\m=88.02g[/tex]

Regards!

Answer:

n = 0.21 moles

Explanation:

Given that,

Volume, V = 0.84 L

Pressure, P = 4.6 atm

T = 222 K

We need to find the number of moles of Neon gas. We know that,

PV = nRT

Where

n is the number of moles

R i the gas constant, R = 0.08206 L-atm/mol-K

Put all the values,

[tex]n=\dfrac{PV}{RT}\\\\n=\dfrac{4.6\times 0.84}{0.08206 \times 222}\\\\n=0.21\ \text{moles}[/tex]

So, there are 0.21 moles of Neon gas.

The question is incomplete, the complete question is:

A 7.00 L tank at [tex]21.4^oC[/tex] is filled with 5.43 g of sulfur hexafluoride gas and 14.2 g of sulfur tetrafluoride gas. You can assume both gases behave as ideal gases under these conditions. Calculate the mole fraction and partial pressure of each gas. Round each of your answers to significant digits.

Answer: The mole fraction of sulfur hexafluoride is 0.221 and that of sulfur tetrafluoride is 0.779

Explanation:

The number of moles is defined as the ratio of the mass of a substance to its molar mass.  The equation used is:

[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] ......(1)

Given mass of sulfur hexafluoride = 5.43 g

Molar mass of sulfur hexafluoride = 146.06 g/mol

Putting values in equation 1, we get:

[tex]\text{Moles of sulfur hexafluoride}=\frac{5.43g}{146.06g/mol}=0.0372mol[/tex]

Given mass of sulfur tetrafluoride = 14.2 g

Molar mass of sulfur tetrafluoride = 108.07 g/mol

Putting values in equation 1, we get:

[tex]\text{Moles of sulfur tetrafluoride }=\frac{14.2g}{108.07g/mol}=0.1314mol[/tex]

Total moles of gas in the tank = [0.0372+ 0.1314] mol = 0.1686 mol

Mole fraction is defined as the moles of a component present in the total moles of a solution. It is given by the equation:

[tex]\chi_A=\frac{n_A}{n_A+n_B}[/tex] .....(2)

where n is the number of moles

Putting values in equation 2, we get:

[tex]\chi_{SF_6}=\frac{0.0372}{0.1686}=0.221[/tex]

[tex]\chi_{SF_4}=\frac{0.1314}{0.1686}=0.779[/tex]

Hence, the mole fraction of sulfur hexafluoride is 0.221 and that of sulfur tetrafluoride is 0.779

Answer:

climate change

Explanation:

climate change is driving force of evolution because when the climate is changed the animal and human need to adapt to it's natural change.

Answer:

33.8 g Solution

Explanation:

A chemistry student needs 15.0 g of methanol for an experiment. The concentration of ethanol in the solution is 44.4% w/w, that is, there are 44.4 g of methanol every 100 g of solution. The mass of solution that would contain 15.0 g of methanol is:

15.0 g Methanol × 100 g Solution/44.4 g Methanol = 33.8 g Solution

Since 33.8 g are required and 320. g are available, there is enough solution for the requirements.

Answer:

0.375mL of solution of nalorphine must be injected

Explanation:

A solution of 0.40% (w/v) contains 0.40g of solute (In this case, nalorphine), in 100mL of solution. To obtain 1.5mg of nalorphine = 1.5x10⁻³g of nalorphine are needed:

1.5x10⁻³g * (100mL / 0.40g) =

Answer:

The volume of the sample is 17.4L

Explanation:

The reaction that occurs requires the same amount of CO and NO. As the moles added of both reactants are the same you don't have any limiting reactant. The only thing we need is the reaction where 4 moles of gases (2mol CO + 2mol NO) produce 3 moles of gases (2mol CO2 + 1mol N2). The moles produced are:

0.1800mol + 0.1800mol reactants =

0.3600mol reactant * (3mol products / 4mol reactants) = 0.2700 moles products.

Using Avogadro's law (States the moles of a gas are directly proportional to its pressure under constant temperature and pressure) we can find the volume of the products:

V1n2 = V2n1

Where V is volume and n moles of 1, initial state and 2, final state of the gas

Replacing:

V1 = 23.2L

n2 = 0.2700 moles

V2 = ??

n1 = 0.3600 moles

23.2L*0.2700mol = V2*0.3600moles

17.4L = V2

Answer:

Mg will be the limiting reagent.

Explanation:

The balanced reaction is:

Mg + 2 HCl → MgCl₂ + H₂

By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:

Being the molar mass of each compound:

By reaction stoichiometry, the following mass quantities of each compound participate in the reaction:

0.0350 g of Mg is reacted with 10.00 mL (equal to 0.01 L) of 6 M HCl.

Molarity being the number of moles of solute that are dissolved in a certain volume, expressed as:

[tex]Molarity=\frac{number of moles of solute}{volume}[/tex]

in units [tex]\frac{moles}{liter}[/tex]

then, the number of moles of HCl that react is:

[tex]6 M=\frac{number of moles of HCl}{0.01 L}[/tex]

number of moles of HCl= 6 M*0.01 L

number of moles of HCl= 0.06 moles

Then you can apply the following rule of three: if by stoichiometry 2 moles of HCl react with 24.3 grams of Mg, 0.06 moles of HCl react with how much mass of Mg?

[tex]mass of Mg=\frac{0.06 moles of HCl* 24.3 grams of Mg}{2 moles of HCl}[/tex]

mass of Mg= 0.729 grams

But 0.729 grams of Mg are not available, 0.0350 grams are available. Since you have less mass than you need to react with 0.06 moles of HCl, Mg will be the limiting reagent.

The limiting reactant in the reaction is Magnesium (Mg)

From the question,

We are to determine the limiting reactant in the reaction.

The given balanced chemical equation for the reaction is

Mg(s) + 2HCl(aq) → MgCl₂(aq) + H₂(g)

This means

1 mole of Mg is required to react completely with 2 moles of HCl

Now, we will determine the number of moles of each reactant present

Mass = 0.0350 g

Using the formula

[tex]Number\ of\ moles = \frac{Mass}{Atomic\ mass}[/tex]

Atomic mass of Mg = 24.305 g/mol

∴ Number of moles of Mg present = [tex]\frac{0.0350}{24.305}[/tex]

Number of moles of Mg present = 0.00144 mole

Concentration = 6M

Volume = 10.00 mL = 0.01 L

Using the formula

Number of moles = Concentration × Volume

∴ Number of moles HCl present = 6 × 0.01

Number of moles HCl present = 0.06 mole

Since,

1 mole of Mg is required to react completely with 2 moles of HCl

Then

0.00144 mole of Mg is required to react completely with 2×0.00144 mole of HCl

2×0.00144 = 0.00288

∴ The number of moles of HCl required to react completely with the Mg is 0.00288 mole

Since the number of moles of HCl present is more than 0.00288 mole, then HCl is the excess reactant and Mg is the limiting reactant.

Hence, the limiting reactant in the reaction is Magnesium (Mg)

Learn more here: https://brainly.com/question/13979150

Answer: Pair 1 has Mg and Sr, Pair 2 has Kr and Ne, Pair 3 has As and P.

Explanation:

A periodic table is a group of elements presented in a tabular form where elements are arranged in a series of 7 rows and 18 columns.

The vertical columns are known as groups and horizontal rows are known as periods.

The elements having similar chemical properties are arranged in one group.

Magnesium (Mg) is the 12th element of periodic table placed at Group 2 and Period 3

Strontium (Sr) is the 38th element of periodic table placed at Group 2 and Period 5

Krypton (Kr) is the 36th element of periodic table placed at Group 18 and Period 4

Neon (Ne) is the 10th element of periodic table placed at Group 18 and Period 2

Arsenic (As) is the 33rd element of periodic table placed at Group 15 and Period 4

Phosphorus (P) is the 15th element of periodic table placed at Group 15 and Period 3

As magnesium and strontium are present in the same group, they will have similar chemical properties. Similarly, krypton and neon will form the second pair. Likewise, arsenic and phosphorus will form a pair.

Hence, Pair 1 has Mg and Sr, Pair 2 has Kr and Ne, Pair 3 has As and P.