.hlp me to solve mcq​

Answer:

blended is better than synthetic fibre. because blended fabrics have quality of synthetic and natural fibres so they are more better than fabrics. For example terrycot. Blended Fibres are considered better than individual synthetic fibres because they show the advantages of 2 or more fibres.

Answer:

[tex]\boxed{It\ will\ shift\ to\ create\ less\ of\ substance\ A}[/tex]

Explanation:

If the concentration of any substance A in a dynamic equilibrium increases, The equilibrium will be  shifted to its opposite side so that Substance A can be created less and the substance opposite to A can be created more so that a "dynamic equilibrium" can again be established.

Answer:

Reacting hydrogen and oxygen gases to make water

Explanation:

Exothermic means that energy is released into the environment, so let's go through the process of elimination.

Allowing meat to thaw after taking it out of the freezer - NO it is endothermic, and takes energy/heat from the environment to thaw.

Popsicle melting on a warm summer day - NO also endothermic, the opposite of exothermic.

Boiling water in a beaker to convert it to steam - NO because we need to add heat, so it doesn't release any energy.

Rolling a ball up a hill - NO, for a ball to roll up a hill, it needs energy from something else, so it's not exothermic.

Reacting hydrogen and oxygen gases to make water - YES this reaction makes new bonds, which releases energy, so this is exothermic.

Among the following choices reacting hydrogen and oxygen gases to make water is an exothermic reaction as it releases energy as new bonds are formed.

An exothermic reaction is defined as a chemical reaction which involves release of energy in the form of light,heat .In these reactions, energy is transferred from system to surroundings rather than taking energy from surroundings into system as in endothermic reactions.

In an exothermic reaction,change in enthalpy is negative.Therefore, it can be inferred that net amount of energy which is required to start the exothermic reaction is less than the net amount which is released by the reaction.

Examples of exothermic reactions are combustion reactions, detonation of nitroglycerin , neutralization reactions and nuclear fission.

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Answer:

69.66 g

Explanation:

We have the following from the question;

Density of the substance = 5.4 g/ml

Volume of substance = 12.9 ml

Mass of substance= the unknown

Since we have both density and volume of the substance, the question must be for us to obtain the mass of the substance, hence;

Density= mass/volume

Mass= Density × volume

Mass = 5.4 g/ml × 12.9 ml

Mass= 69.66 g

Answer:3.6 x 101 or 8.77 x 10-1

Answer:

Hi there!!!

The answer is given in picture.

In question we had 2 sodium(Na) and chlorine (cl) but after reaction nacl donot contain it. so, we need to put 2 infront of nacl to make them equal.

As balancing chemical equation refers to the process of keeping or making equal to the atoms of both product and reactant.

Hope it helps..

Answer:

170 mL

Explanation:

The total volume to be reported should be 170 mL.

According to the significant rule in mathematical operations, final answers are usually reported to reflect the accuracy of the least accurate number.

In this case, the least accurate of all the volumes has zero significant digits after the decimal, hence, the final answer after the mathematical operation should also have no significant digits after the decimal.

           18 + 128.7 + 23.45 = 170.15

Therefore, the total volume to be reported when significant digits are taken into account would be 170 mL.

Answer:

The answer to your question is given below.

Explanation:

The reaction of sulfuric acid and potassium hydroxide is called neutralisation.

Neutralisation is a reaction involving an acid and a base which produces salt and water only.

For the react between sulfuric acid, H2SO4 and potassium hydroxide, KOH, we can predict the products obtained as follow:

H2SO4 + KOH —>

In solution, H2SO4 and KOH will dissociate as follow:

H2SO4(aq) —> 2H^+(aq) + SO4^2-(aq)

KOH(aq) —> K^+(aq) + OH^-(aq)

H2SO4 + KOH —>

2H^+(aq) + SO4^2-(aq) + K^+(aq) + OH^-(aq) —> K^+(aq) + SO4^2-(aq) + 2H^+(aq) + OH^-

H2SO4 + KOH —> K2SO4 + H2O

Now, we can balance the above equation as follow:

H2SO4 + KOH —> K2SO4 + H2O

There are 2 atoms K on right side and 1 atom on the left side. It can be balance by writing 2 in front of ko as shown below:

H2SO4 + 2KOH —> K2SO4 + H2O

There are 2 atoms of H on the right side and a total of 4 atoms on the left side. It can be balance by writing 2 in front of H2O as shown below:

H2SO4 + 2KOH —> K2SO4 + 2H2O

Now,the equation is balanced.

Answer:

Given the reactants, H2SO4 and KOH, we are asked to determine the product(s) of the reaction. Since H2SO4 is an acid and KOH is a base. This is a neutralization reaction, thus, the products are salt and water.  

So, H+ from H2SO4 will react with OH- from KOH forming H2O. K+ will also react with SO4 2- forming K2SO4. Therefore, the balanced reaction will be:

H2SO4 + 2KOH ---> K2SO4 + 2H2O

Explanation:

An atom Y has atomic number 13, so the no. of electrons and protons in it is 13 and after loses it will form cation and no. of electrons will become 10.

Atomic number of an atom is equal to the number of electrons or protons present in that atom.

Number of protons and electrons in the atom before loses electron is 13, as given atomic number is 13.

Number of elctrons in the atom is 10 and number of protons is 13, as protons are present in the nucleus.

So, number of protons is always same i.e. 13 within the atom and no. of electrons after losing 3 electrons is 10.

To know more about atomic number, visit the below link:
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Answer:

The answer is "Option B"

Explanation:

Law:

In the law of the conservation of matter, states the volume of matter throughout the process remains constant. In any particular case, it is closed to the movement of matter.  It is mostly on conservation of energy means, that the total mass of the products should consider the sum of the mass, which is the reactant of the event of chemical processes.

Reaction:

[tex]2AgClO_3+ Na_2CO_3= Ag_2CO_3+Na_2ClO_3[/tex]

In the above equation when we react to [tex]2AgClO_3[/tex] from the [tex]Na_2CO_3[/tex], it will give [tex]Ag_2CO_3 \ \ \text{and} \ \ Na_2ClO_3[/tex]. that's why option b is correct.

Answer:

Ag2CO3

Explanation:

Answer:

has two double C-C bonds

Explanation:

A saturated compound is a compound having the full complement of hydrogen atoms for every carbon atom while an unsaturated compound does not contain the full complement of hydrogen atoms for every atom of carbon.

If we look at C3H4, the only possible structure of the compound is H2C=C=CH2. We can see from this arrangement that the compound contains a cumulative double bond. This is the specific structure that fits into one of the descriptions in the options, the compound contains two double bonds.

Answer:

The SI unit of volume is the cubic meter (m 3 ), which is the volume occupied by a cube that measures 1 m on each side. This very large volume is not very convenient for typical use in a chemistry laboratory. A liter (L) is the volume of a cube that measures 10 cm (1 dm) on each side.

Answer:

[tex]\large \boxed{350}[/tex]

Explanation:

In multiplication and division problems, the answer can have no more significant figures than the number with the fewest significant figures.

My calculator gives the result:

[tex]\dfrac{4568}{13} = 351.3846154[/tex]

4658 has four significant figures.

     13 has two significant figures.

You must round to two significant figures.

That is, you drop all the digits to the right of the 5 — the red line in Fig. 1 below. You are rounding to the nearest ten.

To round a number to the nearest ten, you look at the number in the ones place (1). See Fig. 2.

If the number to be dropped — the digit in the ones place — is less than 5, you drop the digit in the ones place (Fig. 3). It becomes a zero.

The number in the tens place is a trailing zero. It is not significant.

[tex]\text{The quotient of $\dfrac{4658}{13}$ is $\large \boxed{\mathbf{350}}$}[/tex]

Answer:

The answer is "all the cells are too small, which is not seen by the naked eye, that's why we use a microscope to see it".

Explanation:

In the given question the choices were missing so, we define the correct answer only.

Cells are the essential building blocks of all living entities. There will be trillions of cells within the body. They construct a body shape, absorb nutrients, transform them into energy, and conduct specialized features.  

It provides stability and guidance, encourages mitotic cell development, encourages active and passive transfer, generates energy, induces metabolic processes, and contraceptive support.

Answer:

Physical properties are defined as the properties which can be observed without changing its chemical composition.

For example: color, volume, and molecular weight.

Chemical properties are defined as the properties which can be observed only after changing chemical identity of the substance.

For example: reactivity, toxicity, and flammability.

The fundamental differences between physical and chemical properties are as follows:

Answer:

Chemical properties are related to chemical bonds of the substance while physical properties are not.

In chemical properties, chemical identity of substance changes while physical properties do not have any change.

Chemical properties predict the reaction of substance while physical properties only describe the appearance of the substance.

Explanation:

Answer:

6.05 g

Explanation:

Use the density to convert the volume to a weight.

(5.00 mL) × (1.21 g/mL) = 6.05 g liquid plant food

You will need 6.05 g liquid plant food.

Answer:Particles in plasmas collide more often.

Plasma particles have high kinetic energy (they move quickly).

Plasma particles are far apart.

The ionized particles have no fixed volume

Explanation:

Plasma is the fourth form of matter which has freely moving electrons in it. The substance can be identified as plasma if its particles collide often and are far apart.

Plasma is a type of matter other than solids, liquids, and gas. They have similar properties to that of gas. Plasma particle collides are often like gases as they move freely in space. Like gases that have no definite shape and volume.

The plasma particles have ionic charges, positive and negative resulting in high kinetic energy. This property allows them to show electromagnetism and electrical conductivity.

The ionized particles are due to the high temperature that allows them to have the property of electrical conductivity and compression.

Therefore, the particles of plasma are ionized and have high kinetic energy.

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Answer:

Warm equatorial air rises higher into the atmosphere and migrates toward the poles. This is a low-pressure system. At the same time, cooler, denser air moves over Earth's surface toward the Equator to replace the heated air. ... This happens because Earth's rotation generates what is known as the Coriolis effect

Answer:

CO32−

Explanation:

We have to consider the valencies of the polyatomic ions involved. Recall that it is only a polyatomic ion with a valency of -2 that can form a compound which requires two sodium ions.

When we look closely at the options, we will realize that among all the options, only CO32− has a valency of -2, hence it must be the required answer. In order to be double sure, we put down the ionic reaction equation as follows;

2Na^+(aq) + CO3^2-(aq) ---------> Na2CO3(aq)

Answer:

A).  CO32−

Explanation:

Answer:

a 1) XZ2

2) YZ

3) X2

b 1) Ionic bond

2) Ionic bond

3) covalent bond

c) ionic compounds has high melting and boiling point

ionic compounds can conduct electicity in aqueous form

covalent compounds have electrons shared between the atoms

covalent compounds have lower melting point compared to ionic compound

Answer:

(i) XZ = Potassium Sulfide [K2SO4]

(ii) YZ = Potassium Chloride [KCI]

(iii) X = Sulfur [S]

b) (i) Ionic Bond. (ii) Ionic Bond. (iii) Covalent Bond.

c) (i) Ionic compounds have high melting and boiling points.

(ii) Ionic compounds can conduct electricity in a molten state or a solution as they have ions that can move and carry charge.

(iii) Covalent compounds have low melting and boiling points.

(iv) Covalent compounds can not conduct electricity as all electrons are involved in bonding so there are no free electrons or ions to carry the charge.

Hope this is OK :))

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Answer:

Here is it....

Explanation:

Answer: 0.01 moles (I am guessing)

Explanation:

Firstly, cm3 and ml are equal to one another, therefore 250cm3 can also be written as 250 ml. I Googled and found that ideally, one mole of gas will occupy a volume of 22.4 L (22,400 ml) at s.t.p. 250 ml out of 22,400 ml is 0.01 rounded, therefore I assume that is the answer. About 0.01 mole occupies 250 cm3 at s.t.p.

Answer:

1. 0.97 V

2. [tex]Al_(_s_)/Al^+^3~_(_a_q_)~//~Ag^+~_(_a_q_)/Ag_(_s_)[/tex]

Explanation:

In this case, we can start with the half-reactions:

[tex]Ag^+~_(_a_q_)->~Ag_(_s_)[/tex]

[tex]Al_(_s_)~->~Al^+^3~_(_a_q_)[/tex]

With this in mind we can add the electrons:

[tex]Ag^+~_(_a_q_)+~e^-~->~Ag_(_s_)[/tex]  Reduction

[tex]Al_(_s_)~->~Al^+^3~_(_a_q_)+~3e^-~[/tex] Oxidation

The reduction potential values for each half-reaction are:

[tex]Ag_2S~+~e^-~->~Ag_(_s_)~+~S^-^2~_(_a_q_)[/tex] - 0.69 V

[tex]Al^+^3~_(_a_q_)+~2e^-~->~Al_(_s_)[/tex] -1.66 V

In the aluminum half-reaction, we have an oxidation reaction, therefore we have to flip the reduction potential value:

[tex]Al_(_s_)~->~Al^+^3~+~2e^-~[/tex] +1.66 V

Finally, to calculate the overall potential we have to add the two values:

1.66 V - 0.69 V = 0.97 V

For the second question, we have to keep in mind that in the cell notation we put the anode (the oxidation half-reaction) in the left and the cathode (the reduction half-reaction) in the right. Additionally, we have to use "//" for the salt bridge, therefore:

[tex]Al_(_s_)/Al^+^3~_(_a_q_)~//~Ag^+~_(_a_q_)/~Ag_(_s_)[/tex]

I hope it helps!

Answer:

The term supernatural literally means, Science does not deal with the supernatural because within nature, not within it

Answer:

the atomic number of a neon is 10

Answer:

here u go! ................

Answer:

Hope this is ok :))

Explanation:

Answer:

Here are some examples

Explanation:

NaCl

Cation = Na⁺, Anion = Cl⁻; ΔEN = |0.93 - 3.16| = 2.23

MgS

Cation = Mg²⁺, Anion = O²⁻; ΔEN = |1.31 - 3.44| = 2.53

KBr

Cation = K⁺, Anion = Br⁻; ΔEN = |0.82 - 2.96| =  2.14

CaF₂

Cation = Ca²⁺, Anion = F⁻; ΔEN = |1.00 - 3.98| = 2.98

In each case, ΔEN > 1.6, so the compound is ionic.