CSCA Chemistry Test - Jan 2026 — Папа в Китае

Вопрос 1

Which of the following is a chemical property of a substance?

Iron nails easily rust in a humid environment The density of copper is 8.9 g·cm$^{-3}$ Platinum wire turns red when heated Aluminum is a silver-white metal

Вопрос 2

Which of the following instruments is used for accurately measuring liquid volume?

Measuring cylinder Beaker Balance Gas collection bottle

Вопрос 3

In the laboratory, hydrogen is prepared using:

Iron and concentrated sulfuric acid Magnesium and concentrated nitric acid Copper and dilute sulfuric acid Zinc and dilute sulfuric acid

Вопрос 4

The structural formula of acetic acid is:

$\text{CH}_3\text{CH}_2\text{OH}$ $\text{CH}_3\text{OCH}_3$ $\text{CH}_3\text{COOH}$ $\text{CH}_3\text{CHO}$

Вопрос 5

Which of the following statements about $^{13}\text{C}$ is incorrect?

$^{13}\text{C}$ and $^{12}\text{C}$ have the same number of electrons $^{13}\text{C}$ and $^{12}\text{C}$ have the same number of protons $^{13}\text{C}$ and $^{12}\text{C}$ have the same number of neutrons $^{13}\text{C}$ is an isotope of $^{12}\text{C}$

Вопрос 6

At 25°C, which of the following solutions has a pH of 1?

0.1 mol·L$^{-1}$ hydrochloric acid solution 0.1 mol·L$^{-1}$ sulfuric acid solution 0.1 mol·L$^{-1}$ sodium hydroxide solution 0.1 mol·L$^{-1}$ acetic acid solution

Вопрос 7

When observing the flame test for potassium, blue cobalt glass is used to:

Filter out the yellow light of sodium Protect the eyes from burns Enhance the purple light of potassium Increase the observation temperature

Вопрос 8

Which of the following groups of substances can form a solution with water?

Ethyl acetate Ethanol Benzene Calcium carbonate

Вопрос 9

Which of the following substances is a pure substance?

Medical alcohol Concrete Copper Saline solution

Вопрос 10

Which of the following substances is a homolog of $\text{C}_9\text{H}_{16}$?

$\text{C}_4\text{H}_8$ $\text{C}_4\text{H}_{10}$ $\text{C}_5\text{H}_8$ $\text{C}_8\text{H}_{10}$

Вопрос 11

In which of the following reactions does sulfuric acid act as an oxidizing agent?

$2\text{NaCl} + \text{H}_2\text{SO}_4 \to \text{Na}_2\text{SO}_4 + 2\text{HCl}$ $\text{H}_2\text{SO}_4 + \text{Ba(NO}_3)_2 \to 2\text{HNO}_3 + \text{BaSO}_4 \downarrow$ $\text{S} + 2\text{H}_2\text{SO}_4 \to 3\text{SO}_2 + 2\text{H}_2\text{O}$ $2\text{KOH} + \text{H}_2\text{SO}_4 \to \text{K}_2\text{SO}_4 + 2\text{H}_2\text{O}$

Вопрос 12

Which of the following substances belongs to electrolyte?

Sucrose Carbon dioxide Metal aluminum NaCl

Вопрос 13

When 1 mole of hydrogen burns completely in oxygen, the mass of water produced is:

4.5 g 9 g 27 g 18 g

Вопрос 14

Which of the following substances is an electrolyte?

Magnesium Sodium chloride Toluene Helium

Вопрос 15

Which of the following atoms is most likely to lose electrons and form a cation?

Na Mg Cl F

Вопрос 16

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

$\text{CH}_4$ and $\text{C}_3\text{H}_8$ $^{12}\text{C}$ and $^{14}\text{C}$ $\text{CO}$ and $\text{CO}_2$ Diamond and graphite

Вопрос 17

In which of the following substances is the oxidation number of Cl +5?

$\text{NaClO}_3$ $\text{NaClO}_4$ $\text{CaCl}_2$ $\text{NaClO}$

Вопрос 18

Which of the following represents the electron configuration diagram of an argon atom?

Option A Option B Option C Option D

Вопрос 19

Which of the following gases can be collected using both downward displacement of air and water displacement?

$\text{CO}_2$ $\text{N}_2$ $\text{H}_2$ $\text{NH}_3$

Вопрос 20

Take 50 mL of NaOH solution from 1 L of 1 mol·L$^{-1}$ NaOH solution. The molar concentration of this 50 mL NaOH solution is:

0.02 mol·L$^{-1}$ 1 mol·L$^{-1}$ 2 mol·L$^{-1}$ 0.2 mol·L$^{-1}$

Вопрос 21

Which of the following substances can oxidize $\text{Fe}^{2+}$ to $\text{Fe}^{3+}$?

$\text{Cl}_2$ Fe Zn NaOH

Вопрос 22

At 25°C, which of the following substances can react with both HCl and NaOH?

$\text{NaHCO}_3$ $\text{Ca(OH)}_2$ $\text{CH}_3\text{COOH}$ NaCl

Вопрос 23

Which of the following elements has the smallest atomic radius?

O C Na F

Вопрос 24

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

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

Вопрос 25

If 4.0g of copper(II) oxide is completely reduced by $\text{H}_2$, the volume of $\text{H}_2$ consumed under standard conditions is:

11.2L 22.4L 2.24L 1.12L

Вопрос 26

The English name for $\text{NaNO}_2$ is:

Ammonium nitrate Sodium nitride Sodium nitrite Sodium nitrate

Вопрос 27

Which of the following substances, when dissolved in water, produces the solution with the highest pH?

NaCl $\text{HNO}_3$ $\text{H}_2\text{S}$ $\text{NH}_3$

Вопрос 28

The reaction between hydrochloric acid and sodium hydroxide belongs to:

decomposition reaction displacement reaction combination reaction neutralization reaction

Вопрос 29

Which of the following substances contains both ionic and covalent bonds?

$\text{Na}_2\text{O}_2$ $\text{CO}_2$ $\text{H}_2\text{O}$ KCl

Вопрос 30

Which of the following is a displacement reaction?

$2\text{NaHCO}_3 \to \text{Na}_2\text{CO}_3 + \text{H}_2\text{O} + \text{CO}_2 \uparrow$ $\text{Fe} + \text{CuSO}_4 \to \text{FeSO}_4 + \text{Cu}$ $2\text{H}_2 + \text{O}_2 = 2\text{H}_2\text{O}$ $\text{CH}_4 + 2\text{O}_2 = \text{CO}_2 + 2\text{H}_2\text{O}$

Вопрос 31

In the laboratory preparation of oxygen from $\text{H}_2\text{O}_2$, the commonly used catalyst is:

Manganese dioxide Potassium chloride Sodium hydroxide Potassium chlorate

Вопрос 32

Which of the following substances has bleaching properties?

$\text{KClO}_3$ Dry $\text{Cl}_2$ NaCl HClO

Вопрос 33

In the periodic table, the element located in the second period and Group VIIA is:

Oxygen Nitrogen Fluorine Chlorine

Вопрос 34

Which of the following ions can coexist in large quantities in an aqueous solution?

$\text{Mg}^{2+}$, $\text{Cl}^-$, $\text{NH}_4^+$, $\text{SO}_4^{2-}$ $\text{Ca}^{2+}$, $\text{SO}_4^{2-}$, $\text{CO}_3^{2-}$, $\text{Na}^+$ $\text{CO}_3^{2-}$, $\text{Na}^+$, $\text{SO}_4^{2-}$, $\text{H}^+$ $\text{OH}^-$, $\text{Ca}^{2+}$, $\text{Mg}^{2+}$, $\text{NO}_3^-$

Вопрос 35

In a beaker containing 50 mL of saturated potassium nitrate solution, the method to change the mass fraction of the solute is:

Evaporate some solvent at constant temperature Increase the solution temperature Decrease the solution temperature Add potassium nitrate solid

Вопрос 36

What reagents can be used to detect $\text{Cl}^-$ ions?

$\text{Ba(NO}_3)_2$ and dilute nitric acid $\text{AgNO}_3$ and dilute sulfuric acid $\text{BaCl}_2$ and dilute hydrochloric acid $\text{AgNO}_3$ and dilute nitric acid

Вопрос 37

Which of the following substances contains the largest number of atoms?

11.2 L of $\text{CH}_4$ under standard conditions 2 g He $3.01 \times 10^{23}$ Al atoms 1 mol HF

Вопрос 38

For the endothermic reaction $\text{C(s)} + \text{H}_2\text{O(g)} \rightleftharpoons \text{CO(g)} + \text{H}_2\text{(g)}$, what can cause the equilibrium to shift in the opposite direction?

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

Вопрос 39

$\text{H}_2$ is mixed with small amounts of $\text{CO}_2$ and $\text{NH}_3$. To purify $\text{H}_2$, the mixed gas should be passed through ( ) in sequence.

Concentrated $\text{H}_2\text{SO}_4$, NaOH(aq) CaO, NaOH(aq) NaOH(aq), CaO NaOH(aq), concentrated $\text{H}_2\text{SO}_4$

Вопрос 40

When 12g of carbon powder burns in 0.8 mol of oxygen, and all the carbon is consumed, the resulting gas contains:

Possibly both CO and $\text{CO}_2$ Only CO $\text{CO}_2$ and $\text{O}_2$ Only $\text{CO}_2$

Вопрос 41

The method to remove a small amount of $\text{NaHCO}_3$ from $\text{Na}_2\text{CO}_3$ solid is to:

Introduce carbon dioxide Add sodium hydroxide Heat Add dilute hydrochloric acid

Вопрос 42

For the reaction $2\text{HI(g)} \rightleftharpoons \text{H}_2\text{(g)} + \text{I}_2\text{(g)}$ (forward reaction is exothermic), which of the following will shift the equilibrium to the right?

Raise the temperature Add a catalyst Increase the system pressure Remove $\text{H}_2$

Вопрос 43

Regarding the reaction $\text{CH}_3\text{COOH} + \text{C}_2\text{H}_5\text{OH} \xrightarrow[\Delta]{\text{H}_2\text{SO}_4} \text{CH}_3\text{COOC}_2\text{H}_5 + \text{H}_2\text{O}$ (where concentrated sulfuric acid is added), which of the following statements is incorrect?

Concentrated sulfuric acid can absorb the produced water, facilitating the reaction Concentrated sulfuric acid acts as a catalyst in the reaction This reaction can be controlled to completely convert reactants into products This reaction is an esterification reaction

Вопрос 44

When 0.1 mol of Na reacts with 37.8 g of water, the mass fraction of the resulting NaOH solution is:

15% 10% 25% 20%

Вопрос 45

The electron configuration of a ground-state potassium atom is:

$1s^22s^22p^73s^23p^6$ $1s^22s^22p^63s^23p^64s^1$ $1s^22s^22p^63s^23p^63s^24p^1$ $1s^22s^12p^43s^23p^64s^2$

Вопрос 46

A certain white powder is composed of two substances, and the following experiments are conducted to identify its composition: 1) Take a small amount of sample and add sufficient water, the solid partly dissolves. Then add a sufficient amount of dilute hydrochloric acid, bubbles are formed, and the solid completely dissolves. 2) Take a small amount of sample and add sufficient dilute sulfuric acid, bubbles are produced. After shaking, there is still solid present. The white powder may be:

$\text{CaCO}_3$, $\text{BaCO}_3$ $\text{AgNO}_3$, $\text{Na}_2\text{CO}_3$ NaOH, $\text{CuSO}_4$ $\text{Na}_2\text{CO}_3$, $\text{BaCO}_3$

Вопрос 47

Scientists studied a new material containing three short-period elements X, Y, and Z with increasing nuclear charges. The outermost electron number of X is twice that of its sub-outer layer. The M-shell electron number of Y is half of its L-shell electron number. The sub-outer electron number of Z is one more than its outermost electron number. Which of the following statements is incorrect?

The compound of X and Z is insoluble in water All three elements are nonmetals X and Y belong to the same group The atomic radius of Y is smaller than that of Z

Вопрос 48

The laboratory electrolysis of brine is shown in the diagram. Which of the following statements is correct?

After adding phenolphthalein to the U-tube, the solution near port a turns red over time The gas released at port a turns moist litmus paper red The gas released at port b burns with a blue flame For every 1 mole of electrons transferred in the circuit, the volume of gas released at port b is 22.4 L (standard conditions)