Calculate the amount of solid NaOH in the initial 0.1 M NaOH solution portion that was diluted.

$$\text{Moles} = \text{Molarity} \times \text{Volume (in L)}$$ $$\text{Moles of NaOH} = 0.1 \text{ mol/L} \times 0.005 \text{ L}$$ $$\text{Moles of NaOH} = 0.0005 \text{ mol}$$

$$\text{Molar mass of NaOH} = \text{Na} + \text{O} + \text{H}$$ $$\text{Molar mass of NaOH} = 23 + 16 + 1 = 40 \text{ g/mol}$$

$$\text{Mass} = \text{Moles} \times \text{Molar mass}$$ $$\text{Mass of NaOH} = 0.0005 \text{ mol} \times 40 \text{ g/mol}$$ $$\text{Mass of NaOH} = \boxed{0.02 \text{ g}}$$

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Question 4: Study the diagrams below carefully

a) Identify the types of crops illustrated in A, B and C.

• A: Cocoyam
• B: Cassava
• C: Sweet potato

b) What type of storage organ does each of the crops A, B and C represent?

• A: Corm (modified stem)
• B: Tuberous root (modified adventitious root)
• C: Tuberous root (modified adventitious root)

c) Name the parts labeled I, II, III, IV, V and VI.

• I: Scaly leaves (or leaf scars)
• II: Cormel (or sucker)
• III: Main corm
• IV: Fibrous roots
• V: Tuberous root (or storage root)
• VI: Adventitious roots (or root hairs)

d) Tabulate three structural differences between the crops A and C.

Feature	Crop A (Cocoyam)	Crop C (Sweet potato)
Type of organ	Modified stem (corm)	Modified root (tuberous root)
External features	Has scaly leaves/leaf scars and buds ("eyes")	Has adventitious roots/root hairs; lacks scaly leaves
Growth pattern	Grows as a compact, often rounded, underground stem	Grows as an elongated, irregular swollen root

e) State the usual methods of propagation of each of the crops in B and C.

• B (Cassava): Stem cuttings
• C (Sweet potato): Stem cuttings (slips) or sprouts from the tuberous roots