أسئلة المراجعة

الكلفن

• 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.

أيونه يمكن أن تتحرك

• 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.

استخدم معادلة موزونة وحول الكتلة إلى كمية

• 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 مول

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

يبقى طوله ذرتي كربون

• 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 مول

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

كسر رابطة تساهمية

• 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.

نفس الحجم الذي يتم تسليمه نفس العدد من المرات

• 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 استخدام

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

سرعة التفاعل

• Use ΔG = ΔH - TΔS with consistent energy units. A negative Gibbs energy change indicates thermodynamic favourability for the stated conditions, not a fast rate. An activation barrier can make a favourable process slow.

-10 كيلو جول/مول

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

لتجنب التخفيف بسبب الماء المتبقي

• 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 سم³

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

معدلاتهما

• 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 سم³/ثانية

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

معدلات التفاعل الأمامي والعكسي

• 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.

يكتسب إلكترونات

• 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 مول

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

ميزان يقرأ 0.20 غرام وهو فارغ

• 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.