คำถามทบทวนความรู้

เคลวิน

• At fixed amount and volume, pressure is proportional to kelvin temperature. At fixed temperature and amount, pressure is inversely proportional to volume. State which quantities are fixed before choosing a relationship.

140 kPa

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

ไอออนของมันสามารถเคลื่อนที่ได้

• To explain a bulk property, name the structure, particles, forces and mobile charge carriers. Simple molecular substances can have strong covalent bonds inside molecules but weak attractions between molecules.

18

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

ใช้สมการที่สมดุลและแปลงมวลเป็นปริมาณ

• Calculate the amount available for each reactant and divide by its coefficient. The smaller ratio limits the reaction. Use that reactant to calculate the maximum product before comparing actual yield.

0.05 โมล

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

ยาวสองคาร์บอนเท่าเดิม

• Distinguish addition, substitution, oxidation and polymerization by tracing bonds before and after reaction. Conditions and reagents belong to the reaction arrow; they are not interchangeable labels.

0.15 mol

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

การสลายพันธะโคเวเลนต์

• Use energy transferred = mass × specific heat capacity × temperature change. Convert joules to kilojoules before dividing by reaction amount. An exothermic molar enthalpy change has a negative sign.

840 J

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

ปริมาณเท่าเดิมที่ส่งไปเท่าจำนวนครั้ง

• Define the functional unit before comparing products. The same delivered service, such as carrying one litre of water a hundred times, is fairer than comparing one object with another regardless of lifetime.

20 ครั้ง

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

เพื่อหลีกเลี่ยงการเจือจางจากน้ำตกค้าง

• Calculate the known amount first, apply the stoichiometric ratio, then divide by the unknown solution volume in cubic decimetres. Use concordant titres as required by the school method and report the accepted values.

22.25 cm³

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

อัตราของปฏิกิริยา

• A product-time graph has a steeper gradient where rate is larger. A tangent estimates instantaneous rate; a secant gives average rate over an interval. The final plateau reflects the total collected product under the stated conditions.

0.6 cm³/s

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

อัตราปฏิกิริยาไปข้างหน้าและย้อนกลับ

• A concentration or pressure change disturbs the balance. The system responds toward a new equilibrium. Temperature changes can also change the equilibrium constant; a catalyst changes how quickly equilibrium is reached.

4

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

มันรับอิเล็กตรอน

• Predict products using the specified electrolyte and electrode material. In an aqueous solution, hydrogen or oxygen may form because water-related species compete. Molten salts contain only the ions of the salt.

0.4 mol

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

เครื่องชั่งอ่านค่า 0.20 g เมื่อว่างเปล่า

• For a product or quotient, adding fractional uncertainties is a common maximum-uncertainty approximation. For a difference, add absolute uncertainties. A nonzero intercept can reveal an offset or an incomplete model.

2.5 %

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.