chemistry

100問 • 1年前

問題一覧

The electronic configuration of cu2+ ion is :The electronic configuration of cu2+ ion is :

3d9 4s0

Which is the correct order for the listed atoms with increase of the atomic radius :Which is the correct order for the listed atoms with increase of the atomic radius :

B , Be , Li , Na

A π-bond is the result of :A π-bond is the result of :

overlap of two p-orbitals

What is the ground electronic state of Mn 2+

1s2 2s2 2p6 3s2 3p6 3d5

The capability of alcohols to form intermolecular hydrogen bonds leads to:

decreased vapor pressure

Which is the correct order of halogen ions with decrease of reductive properties?

I- , Br-, Cl- , F-

The the element X has an atomic number of 8 and a mass number of 17. The atoms of this element contain :

9 neutrons

Which of the following elements exists as a monoatomic gas under standard conditions?

neon

Hydrogen may NOT be obtained by

interaction of cooper and nitric acid

The industrial process of production of sulphuric acid includes the following stages

production of SO2 , catalytic oxidation to SO3 and interaction of SO3 with water

Mark the line which includes only salts, whose water solutions are basic:

Sodium carbonate, potassium sulphide, potassium phosphate

Chlorine CANNOT be obtained

By interaction of sodium chloride with concentrated sulphuric acid

Increasing the pressure in an equilibrium system containing gas molecules leads to the withdrawal of the chemical equilibrium in the direction of the reaction

Flowing with decrease in the gas molecules number

At two fold increase of the pressure the rates of the straight and the reverse reaction of the system A(g) + 2B(g) = AB2(g) are changed accordingly

Straight -increased 8 times, reverse-increased 2 times

10 moles of benzene contain

6.02*10 *24 benzene molecules

In oxidative -reduction processes the reducer

Increases its oxidation number

In oxidative-reductive processes the oxidising agent

Decreases its oxidation number

Oxidative reductive processes could be

All answers are correct

The oxidation number for hydrogen in NaH is

-1

When nonspontaneous redox reactions occure by use of a direct electric current, the process is called

Electrolysis

The hydroxonium ion is represented as

H3O+

The chemical elements presented are arranged in order of decrease in their reactivity according to the activity series of metals. Ca , Na , Mg , Zn , Fe , H , Cu , Hg , Ag , Au Which is the best reducing agent ,which is oxidised the easiest?

The cathode in an electrochemical cell is the electrode that is

The electrode where reduction takes place

With addition of a catalyst to a system at equilibrium

The forward and reverse reactions rates are increased equally

The chemical reaction 2Cl2 + H2O —><—O2 + 4HCl is in chemical equilibrium. The rate of the forward reaction is

Equal to the rate of the reverse reaction

Hydrogen peroxide is easily decomposed to water and oxygen according to the reaction 2H2O2–> 2H2O + O2 . It’s ability is increased in the presence of H3PO4

H3PO4 negative Catalyst and the catalysis is homogenous

How many times the rate of the reaction 2NO + O2 —> 2NO2 will increase if the concentration of all substances is increased two times

8 times

The reaction rate of a multistage reaction is determined by

The rate of the slowest stage

The chemical elements of group IB have

1 electron in their outermost electronic shell

The isotopes

Occupy one and the same location in the periodic table of elements

The principal quantum number

All answers are correct

There azimuthal quantum number

All answers are correct

Finding the permitted states of electrons

Is done with the help of Pauli’s principal

Which statement for an equilibrium system is true?

The rate of the straight and reverse reaction are equal

The equilibrium constant of a given reaction depends on

The nature of the reactants and the temperature

Henry’s law is Is followed when

There is no chemical interaction between the dissolving gas and the solvent

The Tyndall effect is due to

Dispersion of the light

Indicate the wrong statement

The equilibrium constant depends on the presence of catalysts

How the degree of electrolyte dissociation(a) and the dissociation constant (KD)of solution of HCN will change upon increasing its concentration

a decreases, KD is not changed

The foam is a system of

Gas dispersed in liquid

If to an aqueous solution of HCN is added NaOH the degree of electrolyte dissociation (a) for HCN

Increases

What is the pH value of 0.01M solution of HCl

An aqueous solution of a salt has pH 9. Thus it follows that this is a salt of :

Weak acid and strong base

The maximal oxidation state of the atoms of chemical elements is equal to

The number of the group in which is the element in the periodic table

A colloid of Al(OH)3 with positively charged granules coagulates with the addition of a certain amount of electrolyte. Which of the listed electrolytes, on equal terms( concentration ,volume) will cause the fastest coagulation?

Al2(SO4)3

Which of the presented reactions is NOT oxidative-reductive ?

Interaction of calcium hydroxide with sulphuric acid

For manufacture of nitric acid two oxides are used :

NO and NO2

On combustion of ammonia, the nitrogen is converted to:

free N2

Which statement about the four quantum numbers which describe electrons in atoms is INCORRECT?

l= subsidiary (or azimuthal) quantum number, l=1,2,3,…,(n+1)

In reaction A has an activation energy of 250 kJ And reaction Bhas an activation energy of 100 kJ which of the following statements MUST be correct?

At the same temperature the rate of reaction B is greater than the rate of reaction A.

In which row against the type of the chemical bond is a suitable listed example?

Covalent polar, simple bond-H2O

The crystalline substance X is very soluble in water, it melts when heated, and its (aqueous solution does NOT conduct electricity. Substance X can be:

Glucose

In which pair of substances is the oxidation number of carbon -4 and +4, respectively?

CH4, CaCO3

Which of the following substances is the electrolyte?

CH3COOH

At constant temperature an aqueous solution of glucose with concentration of 1mol/L compared to water has

Higher osmotic pressure

In which of the indicated pairs there is NO correspondence between the chemical formula and the name of the substance?

Na2O2-disodium oxide

Interaction does NOT occur between aqueous solutions of

CuSO4 and NaCl

The maximum number of electrons in the third electron shell of atoms is

The rate of a chemical reaction Fe(s) + H2SO4(l) —>FeSO4(l) + H2(g) does NOTdepend on

The pressure

From the fact that two aqueous solutions of glucose and sucrose have the same osmotic pressure, it can be concluded that the solutions are

Isotonic

The mass of the solute and the mass of water in 150 g of an aqueous solution of potash (K2CO3) with a mass fraction of 5% are, respectively

7,5g K2CO3 and 142,5g H2O

Two fructose solutions (1) and (2) have concentrations c1 and c2 such that of c1<c2. The boiling points(Tk1 and Tk2) of the solutions can be said that

Tk1<Tk2

When AgNO3(l) is added to an aqueous solution, a white precipitate is obtained. This indicates the possible presence of.

Cl- ions

Hydrogen is released during which reaction?

Na(s) + HCl(l)

The kinetic equation of the reaction 2CO(g) + O2(g) —> 2CO2(g) + Q is

v= k*c(CO)*c(O2)

During the hydrolysis of salts, heat is absorbed, which means that the process is

Endothermic and the heat effect is denoted by -Q

If the pressure in the equilibrium system is lowered :CO2(g)+ C(s) —><— 2CO(g) -Q then

c(CO)increases

If a salt crystal is placed in a glass of an aqueous salt solution and the size of the crystal does not change over time it can be concluded that the solution is

Saturated

What is substance X in the transition Ca(HCO3)2–>X—>CaO?

CaCO3

When the concentration of carbon monoxide doubles the rate of the chemical reaction 2CO(g)+ O2(g) —> 2CO2(g) +!Q

Decreases

In which of the transitions is there a conversation that is NOT possible

Cu—>CuO—>Cu(OH)2—>CuSO4

Solutions of sulphuric acid and dipotassium sulphate can be distinguished by

The colour change of the litmus

Nitrogen is NOT characterised by interaction with

Water

The simple substances of which of the listed chemical elements: A-Cooper, B-iron, C-silver D-aluminium, E-chrome, can react with concentrated sulphuric and nitric acid when heated?

A and C

Which electron subshell in the lanthanides is NOT completely filled

Which of the following oxides is the only anhydride of nitric acid?

N2O5

The basic salts are obtained after

Incomplete neutralisation of multivalent bases

The acidic salts are obtained after

Incomplete neutralisation of polybasic acids

In what container can an aqueous solution of nickel sulphate be stored

Cooper

What is the reaction of the medium of the aqueous solution of the salt NH4Cl:

Acidic

Specify the colour of the flame of potassium salt

Violet

The hydrolysis constant (Kb) depends on:

The temperature

Which of the numbers shown below has a value closest to the pH of a sodium base solution with a concentration of 10*-4 mol/l

10.2

Which answer consists of salts whose aqueous solutions have a pH close to neutral?

(NH4)2CO3, CH3COONH4

In the reaction: A+B+Q—><—C+D the formation of the products is accompanied by:

Increase in temperature in the system

In the equilibrium system: N2(g)+3H2(g)—><—2NH3(g) at constant temperature

c(N2), c(H2) and c(NH3) are permanent

At a given temperature a saturated solution can become unsaturated when:

Solvent is added

In the reaction: SO2(g)+ 2H2S(g)—>3S(s)+2H2O(l) the oxidising agent is

SO2

Which of the following interactions does NOT occur?

Magnesium and caustic soda

The process of dissolving concentrated H2SO4 in water is:

Exothermic- heat is released

The speed of a homogeneous catalytic process depends on:

the concentration of the starting substances and of the catalyst

Which of the statements is false:

According to the Bronsted-Lowry theory, bases contain hydroxide groups

What is the electric charge of the pellet?

Coincides with the charge of the ions absorbed on the nucleus

Which of the reactions will not produce hydroxide:

CuO + H2O —>

Which of the following statements is not true about catalysts:

They change the heat effect of the reaction

The reaction products of an endothermic process:

Are more unstable than the starting substances

In the presence of a catalyst, the chemical equilibrium shifts

Does not shift

How can the value of the degree of electrolyte dissociation (a) be increased for a solution of the weak electrolyte CH3COONa:

By adding water

The rate constant depends on:

all of the above factors

100

Which of the following statements is not true?

catalysts speed up chemical reactions only at high temperature

chemistry 2

chemistry 2

organic

organic

問題一覧

The electronic configuration of cu2+ ion is :The electronic configuration of cu2+ ion is :

3d9 4s0

Which is the correct order for the listed atoms with increase of the atomic radius :Which is the correct order for the listed atoms with increase of the atomic radius :

B , Be , Li , Na

A π-bond is the result of :A π-bond is the result of :

overlap of two p-orbitals

What is the ground electronic state of Mn 2+

1s2 2s2 2p6 3s2 3p6 3d5

The capability of alcohols to form intermolecular hydrogen bonds leads to:

decreased vapor pressure

Which is the correct order of halogen ions with decrease of reductive properties?

I- , Br-, Cl- , F-

The the element X has an atomic number of 8 and a mass number of 17. The atoms of this element contain :

9 neutrons

Which of the following elements exists as a monoatomic gas under standard conditions?

neon

Hydrogen may NOT be obtained by

interaction of cooper and nitric acid

The industrial process of production of sulphuric acid includes the following stages

production of SO2 , catalytic oxidation to SO3 and interaction of SO3 with water

Mark the line which includes only salts, whose water solutions are basic:

Sodium carbonate, potassium sulphide, potassium phosphate

Chlorine CANNOT be obtained

By interaction of sodium chloride with concentrated sulphuric acid

Increasing the pressure in an equilibrium system containing gas molecules leads to the withdrawal of the chemical equilibrium in the direction of the reaction

Flowing with decrease in the gas molecules number

At two fold increase of the pressure the rates of the straight and the reverse reaction of the system A(g) + 2B(g) = AB2(g) are changed accordingly

Straight -increased 8 times, reverse-increased 2 times

10 moles of benzene contain

6.02*10 *24 benzene molecules

In oxidative -reduction processes the reducer

Increases its oxidation number

In oxidative-reductive processes the oxidising agent

Decreases its oxidation number

Oxidative reductive processes could be

All answers are correct

The oxidation number for hydrogen in NaH is

-1

When nonspontaneous redox reactions occure by use of a direct electric current, the process is called

Electrolysis

The hydroxonium ion is represented as

H3O+

The cathode in an electrochemical cell is the electrode that is

The electrode where reduction takes place

With addition of a catalyst to a system at equilibrium

The forward and reverse reactions rates are increased equally

The chemical reaction 2Cl2 + H2O —><—O2 + 4HCl is in chemical equilibrium. The rate of the forward reaction is

Equal to the rate of the reverse reaction

Hydrogen peroxide is easily decomposed to water and oxygen according to the reaction 2H2O2–> 2H2O + O2 . It’s ability is increased in the presence of H3PO4

H3PO4 negative Catalyst and the catalysis is homogenous

How many times the rate of the reaction 2NO + O2 —> 2NO2 will increase if the concentration of all substances is increased two times

8 times

The reaction rate of a multistage reaction is determined by

The rate of the slowest stage

The chemical elements of group IB have

1 electron in their outermost electronic shell

The isotopes

Occupy one and the same location in the periodic table of elements

The principal quantum number

All answers are correct

There azimuthal quantum number

All answers are correct

Finding the permitted states of electrons

Is done with the help of Pauli’s principal

Which statement for an equilibrium system is true?

The rate of the straight and reverse reaction are equal

The equilibrium constant of a given reaction depends on

The nature of the reactants and the temperature

Henry’s law is Is followed when

There is no chemical interaction between the dissolving gas and the solvent

The Tyndall effect is due to

Dispersion of the light

Indicate the wrong statement

The equilibrium constant depends on the presence of catalysts

How the degree of electrolyte dissociation(a) and the dissociation constant (KD)of solution of HCN will change upon increasing its concentration

a decreases, KD is not changed

The foam is a system of

Gas dispersed in liquid

If to an aqueous solution of HCN is added NaOH the degree of electrolyte dissociation (a) for HCN

Increases

What is the pH value of 0.01M solution of HCl

An aqueous solution of a salt has pH 9. Thus it follows that this is a salt of :

Weak acid and strong base

The maximal oxidation state of the atoms of chemical elements is equal to

The number of the group in which is the element in the periodic table

Al2(SO4)3

Which of the presented reactions is NOT oxidative-reductive ?

Interaction of calcium hydroxide with sulphuric acid

For manufacture of nitric acid two oxides are used :

NO and NO2

On combustion of ammonia, the nitrogen is converted to:

free N2

Which statement about the four quantum numbers which describe electrons in atoms is INCORRECT?

l= subsidiary (or azimuthal) quantum number, l=1,2,3,…,(n+1)

In reaction A has an activation energy of 250 kJ And reaction Bhas an activation energy of 100 kJ which of the following statements MUST be correct?

At the same temperature the rate of reaction B is greater than the rate of reaction A.

In which row against the type of the chemical bond is a suitable listed example?

Covalent polar, simple bond-H2O

The crystalline substance X is very soluble in water, it melts when heated, and its (aqueous solution does NOT conduct electricity. Substance X can be:

Glucose

In which pair of substances is the oxidation number of carbon -4 and +4, respectively?

CH4, CaCO3

Which of the following substances is the electrolyte?

CH3COOH

At constant temperature an aqueous solution of glucose with concentration of 1mol/L compared to water has

Higher osmotic pressure

In which of the indicated pairs there is NO correspondence between the chemical formula and the name of the substance?

Na2O2-disodium oxide

Interaction does NOT occur between aqueous solutions of

CuSO4 and NaCl

The maximum number of electrons in the third electron shell of atoms is

The rate of a chemical reaction Fe(s) + H2SO4(l) —>FeSO4(l) + H2(g) does NOTdepend on

The pressure

From the fact that two aqueous solutions of glucose and sucrose have the same osmotic pressure, it can be concluded that the solutions are

Isotonic

The mass of the solute and the mass of water in 150 g of an aqueous solution of potash (K2CO3) with a mass fraction of 5% are, respectively

7,5g K2CO3 and 142,5g H2O

Two fructose solutions (1) and (2) have concentrations c1 and c2 such that of c1<c2. The boiling points(Tk1 and Tk2) of the solutions can be said that

Tk1<Tk2

When AgNO3(l) is added to an aqueous solution, a white precipitate is obtained. This indicates the possible presence of.

Cl- ions

Hydrogen is released during which reaction?

Na(s) + HCl(l)

The kinetic equation of the reaction 2CO(g) + O2(g) —> 2CO2(g) + Q is

v= k*c(CO)*c(O2)

During the hydrolysis of salts, heat is absorbed, which means that the process is

Endothermic and the heat effect is denoted by -Q

If the pressure in the equilibrium system is lowered :CO2(g)+ C(s) —><— 2CO(g) -Q then

c(CO)increases

If a salt crystal is placed in a glass of an aqueous salt solution and the size of the crystal does not change over time it can be concluded that the solution is

Saturated

What is substance X in the transition Ca(HCO3)2–>X—>CaO?

CaCO3

When the concentration of carbon monoxide doubles the rate of the chemical reaction 2CO(g)+ O2(g) —> 2CO2(g) +!Q

Decreases

In which of the transitions is there a conversation that is NOT possible

Cu—>CuO—>Cu(OH)2—>CuSO4

Solutions of sulphuric acid and dipotassium sulphate can be distinguished by

The colour change of the litmus

Nitrogen is NOT characterised by interaction with

Water

The simple substances of which of the listed chemical elements: A-Cooper, B-iron, C-silver D-aluminium, E-chrome, can react with concentrated sulphuric and nitric acid when heated?

A and C

Which electron subshell in the lanthanides is NOT completely filled

Which of the following oxides is the only anhydride of nitric acid?

N2O5

The basic salts are obtained after

Incomplete neutralisation of multivalent bases

The acidic salts are obtained after

Incomplete neutralisation of polybasic acids

In what container can an aqueous solution of nickel sulphate be stored

Cooper

What is the reaction of the medium of the aqueous solution of the salt NH4Cl:

Acidic

Specify the colour of the flame of potassium salt

Violet

The hydrolysis constant (Kb) depends on:

The temperature

Which of the numbers shown below has a value closest to the pH of a sodium base solution with a concentration of 10*-4 mol/l

10.2

Which answer consists of salts whose aqueous solutions have a pH close to neutral?

(NH4)2CO3, CH3COONH4

In the reaction: A+B+Q—><—C+D the formation of the products is accompanied by:

Increase in temperature in the system

In the equilibrium system: N2(g)+3H2(g)—><—2NH3(g) at constant temperature

c(N2), c(H2) and c(NH3) are permanent

At a given temperature a saturated solution can become unsaturated when:

Solvent is added

In the reaction: SO2(g)+ 2H2S(g)—>3S(s)+2H2O(l) the oxidising agent is

SO2

Which of the following interactions does NOT occur?

Magnesium and caustic soda

The process of dissolving concentrated H2SO4 in water is:

Exothermic- heat is released

The speed of a homogeneous catalytic process depends on:

the concentration of the starting substances and of the catalyst

Which of the statements is false:

According to the Bronsted-Lowry theory, bases contain hydroxide groups

What is the electric charge of the pellet?

Coincides with the charge of the ions absorbed on the nucleus

Which of the reactions will not produce hydroxide:

CuO + H2O —>

Which of the following statements is not true about catalysts:

They change the heat effect of the reaction

The reaction products of an endothermic process:

Are more unstable than the starting substances

In the presence of a catalyst, the chemical equilibrium shifts

Does not shift

How can the value of the degree of electrolyte dissociation (a) be increased for a solution of the weak electrolyte CH3COONa:

By adding water

The rate constant depends on:

all of the above factors

100

Which of the following statements is not true?

catalysts speed up chemical reactions only at high temperature