Kadar Tindak Balas Kimia

Apakah maksud kadar tindak balas untuk tindak balas antara magnesium dan asid hidroklorik?

• Pengurangan jisim magnesium

• Pengurangan jisim magnesium dari semasa ke semasa

• Pengurangan isipadu gas hidrogen

• Pengurangan isipadu gas hidrogen dari semasa ke semasa

The graph shows the volume of gas collected against time. What is the average rate of reaction for that reaction?

• 1.0 cm3 s-1

• 1.5 cm3 s-1

• 2.0 cm3 s-1

• 3.0 cm3 s-1

0.1 mol of magnesium powder reacts with excess dilute sulfuric acid. After 1 minute, 0.04 mol of magnesium is left as residue. What is the average rate of that reaction?

• 1.0 x 10-3 mol s-1

• 1.7 x 10-3 mol s-1

• 4.0 x 10-3 mol s-1

• 6.7 x 10-4 mol s-1

2 g of marble takes 20 seconds to dissolve in excess hydrochloric acid. What is the rate of reaction in this experiment?

• 0.1 g s-1

• 0.2 g s-1

• 10 g s-1

The table shows the total volume of carbon dioxide gas collected at intervals of every 30 seconds for the reaction of marble with dilute hydrochloric acid. Which of the following gives the average rate of reaction in the second minute?

• 0.2 cm3 s-1

• 0.4 cm3 s-1

• 0.6 cm3 s-1

• 1.0 cm3 s-1

The reaction between magnesium and hydrochloric acid is represented by the following equation: Mg + 2HCl → MgCl2 + H2. This reaction slows down because: I. The volume of hydrogen gas increases II. The mass of magnesium decreases III. The concentration of hydrochloric acid decreases IV. The concentration of magnesium chloride increases. Which of the following is correct?

• I, IV only

• II, III only

• II, III, IV only

• I, II, III and IV

The equation shows the reaction between calcium carbonate and hydrochloric acid. 2HCl + CaCO3 → CaCl2 + CO2 + H2O. Among the following changes in the quantity of chemicals, which is suitable for determining the rate of the above reaction?

• Mass of calcium carbonate

• Volume of carbon dioxide gas

• Concentration of hydrochloric acid

• Concentration of calcium chloride

Copper(II) oxide reacts with sulfuric acid to produce copper(II) sulfate and water. Which acid solution will produce the highest initial rate of reaction?

• 100 g H2SO4 in 1000 cm3 of water.

• 50 g H2SO4 in 500 cm3 of water.

• 20 g H2SO4 in 100 cm3 of water.

• 100 g H2SO4 in 50 cm3 of water.

Experiment I uses excess zinc pieces and 50 cm3 of 1.0 mol dm-3 nitric acid. What was used in Experiment II?