CSCA Chemistry Practice Test — Папа в Китае

Вопрос 1

Which of the following is a chemical change?

Activated carbon adsorbing pigments Ice melting into water Iron rusting Hydrochloric acid volatilization

Вопрос 2

The correctly named compound is ( ).

CO — Carbon dioxide Na₂CO₃ — Baking soda FeCO₃ — Iron(II) carbonate CuCl — Copper(II) chloride

Вопрос 3

The incorrectly named compound is ( ).

CH₃CH₂OH — Ethanal CH₂=CH₂ — Ethene HC≡CH — Ethyne CH₃–CH₃ — Ethane

Вопрос 4

The correct chemical notation is ( ).

2 hydrogen molecules: 2H₂ 3 oxygen atoms: 3O 4 water molecules: 4H₂O 5 sodium ions: 5Na⁺

Вопрос 5

Which substance is pure?

Hydrochloric acid Air Saturated brine Ice-water mixture

Вопрос 6

A pair of allotropes is ( ).

Water and hydrogen peroxide Oxygen and liquid oxygen White phosphorus and red phosphorus Ice and dry ice

Вопрос 7

The oxidation states of N in NH₄NO₃ are ( ).

+1, +5 −3, +5 +1, −1 −3, +3

Вопрос 8

Which is a solution?

Saline Peanut oil Distilled water Cement slurry

Вопрос 9

The flame color of sodium chloride in a flame test is ( ).

Pale white Pale blue Yellow Green

Вопрос 10

Which of the following is a non-electrolyte?

Sodium carbonate Sulfuric acid Sucrose Sodium hydroxide

Вопрос 11

Which of the following substances belongs to electrolyte?

Metal aluminum NaCl Sucrose Carbon dioxide

Вопрос 12

Which of the following reactions is a redox reaction?

HCl + NaOH = NaCl + H₂O CO₂ + H₂O = H₂CO₃ Fe + CuSO₄ = FeSO₄ + Cu CaCO₃ → CaO + CO₂↑

Вопрос 13

Which of the following is commonly used as oxidizing agent?

Potassium permanganate Sodium Carbon monoxide Hydrogen gas

Вопрос 14

Which of the following groups consists of allotropes of the same element?

¹²C and ¹⁴C CO and CO₂ Diamond and graphite CH₄ and C₃H₈

Вопрос 15

Which compound's aqueous solution is acidic?

NaCl NaOH Na₂CO₃ NH₄Cl

Вопрос 16

When phenolphthalein is added to a solution and it turns red, the solution is?

Neutral Acidic Basic Unable to determine

Вопрос 17

Which gas can be collected by both water displacement and upward air displacement methods?

Hydrogen Ammonia Oxygen Carbon dioxide

Вопрос 18

Take 10 mL of NaOH solution from 1 L of 1 mol·L⁻¹ NaOH solution. The molar concentration of this 10 mL NaOH solution is ( ).

0.2 mol·L⁻¹ 2 mol·L⁻¹ 1 mol·L⁻¹ 0.02 mol·L⁻¹

Вопрос 19

Which of the following statements is incorrect about substance applications?

75% ethanol can be used for disinfection Carbon can be used as fuel CO can be used for fire suppression O₂ supports combustion

Вопрос 20

The position of sulfur ₁₆S in the periodic table is ( ).

Period 3, Group IVA Period 2, Group VA Period 3, Group VIA Period 2, Group IVA

Вопрос 21

When concentrated sulfuric acid is left exposed to air, what changes occur?

Solution mass decreases Solute mass increases Solvent mass decreases Solution mass increases

Вопрос 22

Which pair of compounds are homologs?

CH₃CH₃ and HC≡CH CH₃CH=CHCH₃ and CH₃C≡CCH₃ CH₃CH₃ and CH₃CH₂CH₃ CH₃CH=CH₂ and CH₃CH₃

Вопрос 23

Which of the following reaction classifications is correct?

Fe₂O₃ + 3CO → 2Fe + 3CO₂ — Single displacement MnO₂ + 4HCl(conc.) → MnCl₂ + Cl₂↑ + 2H₂O — Combination HClO + NaOH = NaClO + H₂O — Double displacement 3Fe + 2O₂ = Fe₃O₄ — Decomposition

Вопрос 24

When the reaction reaches equilibrium, what is always equal in the reaction system?

Forward reaction rate and reverse reaction rate Mass of reactants and products Concentration of reactants and products The time atoms exist in reactant and product molecules

Вопрос 25

Which of the following substances is classified as an oxide?

NaOH O₂ H₂O KClO₃

Вопрос 26

Which of the following statements about catalysts is incorrect?

Catalysts can alter reaction rates A catalyst's mass changes after reaction Some reactions can use different catalysts The chemical properties of a catalyst remain unchanged after reaction

Вопрос 27

Which pair of substances share identical chemical bond types?

O₂ and H₂ NaOH and KCl NaCl and HCl HNO₃ and NH₄NO₃

Вопрос 28

Which of the following glassware is called beaker? (The one with graduations and a spout)

Erlenmeyer flask (conical) Round-bottom flask Funnel with stand Beaker (cylindrical with graduations)

Вопрос 29

When BaCl₂ solution is added to an unknown solution, a white precipitate forms that doesn't dissolve in nitric acid. Which statement is correct?

The solution must contain Ag⁺ The solution may contain CO₃²⁻ The solution may contain SO₄²⁻ or Ag⁺ The solution must contain SO₄²⁻

Вопрос 30

The reaction between hydrochloric acid and sodium hydroxide belongs to ( ).

Neutralization reaction Combination reaction Decomposition reaction Displacement reaction

Вопрос 31

Which elements belong to the same group in the periodic table?

Hydrogen, Lithium, Sodium Carbon, Oxygen, Sulfur Sodium, Magnesium, Aluminum Hydrogen, Carbon, Oxygen

Вопрос 32

The correct order of increasing atomic radius is ( ).

Al < B < Na < Mg Al < B < Mg < Na B < Al < Mg < Na B < Al < Na < Mg

Вопрос 33

The correct electron configuration diagram for sodium (Na) is ( ). Format: +protons electrons

+13: 2, 8, 3 +11: 2, 8, 1 +14: 2, 8, 4 +12: 2, 8, 2

Вопрос 34

At 25°C, after evaporating water from 100 mL of a 0.05 mol·L⁻¹ H₂SO₄ solution and concentrating it to 10 mL, the pH of the resulting solution is ( ).

14 2 1 0

Вопрос 35

For the reaction 2SO₂(g) + O₂(g) → 2SO₃(g) in a 2 L closed container, SO₂ decreases from 1.0 mol to 0.6 mol in 10 seconds. The reaction rate for O₂ is ( ).

0.04 mol·L⁻¹·s⁻¹ 0.02 mol·L⁻¹·s⁻¹ 0.2 mol·L⁻¹·s⁻¹ 0.01 mol·L⁻¹·s⁻¹

Вопрос 36

What reagents can be used to detect Cl⁻ ions?

AgNO₃ and dilute nitric acid BaCl₂ and dilute hydrochloric acid AgNO₃ and dilute sulfuric acid Ba(NO₃)₂ and dilute nitric acid

Вопрос 37

Which equilibrium system will shift toward product formation when either pressure is decreased OR temperature is increased?

C(s) + CO₂(g) ⇌ 2CO(g) (forward is endothermic) N₂(g) + 3H₂(g) ⇌ 2NH₃(g) (forward is exothermic) 2NO₂(g) ⇌ N₂O₄(g) (forward is exothermic) 3O₂(g) ⇌ 2O₃(g) (forward is endothermic)

Вопрос 38

Which of the following is a substitution reaction?

Ethene with hydrogen chloride Benzene with hydrogen Methane with chlorine Ethene with water

Вопрос 39

The correct statement about organic compounds is ( ).

Carbon-containing compounds may be organic or inorganic All exhibit isomerism They contain only carbon and hydrogen They cannot be synthesized artificially

Вопрос 40

When 0.02 mol of water undergoes photolysis to produce hydrogen, which statement is correct?

Produces 0.02 g of H₂ Produces 0.01 mol of H₂ Produces 0.224 L of H₂ (at STP) Produces 0.02 mol of H₂

Вопрос 41

Which solution has a concentration of 0.5 mol/L?

1 L solution containing 40 g NaOH 1 L solution containing 1 mol K⁺ from K₂SO₄ 11.2 L HCl (STP) dissolved in water to make 1 L solution 20 g NaOH dissolved in 1 L of water

Вопрос 42

For the endothermic reaction C(s) + H₂O(g) ⇌ CO(g) + H₂(g), what can cause the equilibrium to shift in the opposite direction (toward reactants)?

Increase temperature, decrease pressure Increase temperature, increase pressure Decrease temperature, increase pressure Decrease temperature, decrease pressure

Вопрос 43

The liquid that, together with fresh Cu(OH)₂, forms a red Cu₂O precipitate is ( ).

CH₃COOCH₂CH₃ (ethyl acetate) CH₃CHO (acetaldehyde) CH₃COOH (acetic acid) CH₃CH₂OH (ethanol)

Вопрос 44

Which ions can coexist in large amounts in solution?

Acidic solution: Fe³⁺, SO₄²⁻, NO₃⁻, Mg²⁺ Acidic solution: Na⁺, Ag⁺, Cl⁻, NO₃⁻ Basic solution: Al³⁺, NO₃⁻, Cl⁻, HCO₃⁻ Basic solution: Ba²⁺, Na⁺, CO₃²⁻, Cl⁻

Вопрос 45

A 23.4 g mixture of Cu and CuO yields 20.2 g pure Cu after reduction with CO. The original CuO mass was ( ).

40 g 32 g 16 g 20 g

Вопрос 46

In a chemistry experiment, which operation achieves its target? (4) Bubble CO₂ through C₆H₅ONa solution → solution becomes cloudy → Compare acidity of carbonic acid to phenol

Operation 1: Add excess NaOH to ZnCl₂ to produce Zn(OH)₂ Operation 2: Evaporate AlCl₃ solution to produce anhydrous AlCl₃ Operations 1 and 2 Operation 4: CO₂ through phenolate to compare acidity

Вопрос 47

A white powder is tested: (1) Partly dissolves in water; adding HCl produces bubbles and fully dissolves. (2) Adding H₂SO₄ produces bubbles but solid remains. The powder may be ( ).

NaOH, CuSO₄ CaCO₃, BaCO₃ AgNO₃, Na₂CO₃ Na₂CO₃, BaCO₃

Вопрос 48

A Na–O₂ secondary battery uses NaClO₄ in organic solvent as electrolyte. Total reaction: O₂ + 2Na ⇌ Na₂O₂. Which statement is correct?

When discharged, ClO₄⁻ moves to cathode Anode reaction when discharging: Na⁺ + e⁻ → Na O₂ is released when discharging, O₂ is absorbed when charging Cathode reaction when charging: Na₂O₂ – 2e⁻ → 2Na⁺ + O₂