RATE OF REACTION

Which of the following reactions occurs at the highest rate?

• Photosynthesis

• Rusting of iron

• Combustion of hydrogen in oxygen

• Combustion of magnesium in oxygen

The following equation shows the reaction between calcium carbonate, CaCO₃ and hydrochloric acid, HCl:

CaCO_3(aq) + 2HCl_(aq) → CaCl_2(aq) + CO_{2 (g)­­} + H₂O_(l)

Which of the following is the suitable method to determine the rate of reaction?

• Change in the temperature of the solution with time

• Change in the volume of carbon dioxide gas with time

• Change in the mass of water with time

• Change in the concentration of hydrochloric acid with time

Table 4 shows the total volume of gas evolved at different intervals for the dissociation of hydrogen peroxide.

What is the average rate of reaction in the second minute?

• 14.0 cm³ min^-1

• 16.0 cm³ min^-1

• 18.0 cm³ min^-1

• 28.0 cm³ min^-1

Tags

NGSS.HS-PS1-5

An experiment is carried out to study the effect of concentration on the rate of reaction between sodium thiosulphate and hydrochloric acid.

Graph of the concentration of sodium thiosulphate against 1/time is as shown.

Based on the graph, what is the value of t if the experiment is repeated using sodium

thiosulphate solution 0.025 mol dm^-3.

• 32.3 s

• 50.0 s

• 0.020 s

• 0.031s

Diagram 4 shows the graph of volume of carbon dioxide gas against time when 5 g of marble chips is added to

50 cm³ of 0.2 mol dm^-3 hydrochloric acid.

At what time the rate of reaction the highest?

• t1

• t2

• t3

• t4

Diagram 7 shows a graph of the volume of gas produced against time for the reaction between zinc granules and hydrochloric acid.

The gradient of the graph decreases with time because

• catalyst is not used

• volume of mixture decreases

• temperature of reaction decreases

• concentration of hydrochloric acid decreases

Tags

NGSS.HS-PS1-5

The equation represents the reaction between sodium carbonate and hydrochloric acid.

Na₂CO₃ + 2 HCl → 2 NaCl + H₂O + CO₂

The mass of the beaker and its contents is plotted against time.

Which graph represents what happens when sodium carbonate reacts with an excess of dilute hydrochloric acid?

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Tags

NGSS.HS-PS1-5

Table 9 shows the experiments carried out to study the rate of reaction between zinc carbonate and nitric acid.

Which of the following graph represents the two experiments?

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Figure 12 shows the apparatus set-up to determine the rate of reaction between calcium carbonate and hydrochloric acid.

Which of the following is not correct in the apparatus set-up for this experiment?

• Fixing of cork

• Position of thistle funnel

• Position of the delivery tube in the basin.

• Position of the delivery tube in the conical flask.

Magnesium reacts with acid to produce hydrogen gas, H₂.Which solution would give the highest initial rate of reaction?

• 100 cm³ of 1.0 mol dm^-3 of nitric acid, HNO₃

• 100 cm³ of 1.0 mol dm^-3 of hydrochloric acid, HCl

• 100 cm³ of 1.0 mol dm^-3 of sulphuric acid, H₂SO₄

• 100 cm³ of 1.0 mol dm^-3 of ethanoic acid, CH₃COOH