Correct Answer: A. alkenes

Explanation

(a) Avogadro's law states that equal volumes of all gases at the same temperature and pressure contain the same number of molecules.

(b)(i) Gaseous state (ii) Solid state (iii) Gaseous state.

Explanation

R = \(U\sqrt{\frac{2H}{g}}\)

H = \(\frac{gR^2}{2U^2} = \frac{10 \times 45^2}{2 \times 15^2}\)

Correct Answer: D. anxiety

Correct Answer: D. lyric

Correct Answer: B. 55

Explanation

To find the octane number of the fuel:

The octane number is defined as the percentage by volume of 2,2,4-trimethylpentane (isooctane) in a mixture of isooctane and n-heptane that has the same anti-knocking characteristics as the fuel under test:

• Isooctane has an octane rating of 100.

• n-Heptane has an octane rating of 0.

Since the densities of 2,2,4-trimethylpentane (\approx 0.692 g/cm^3) and n-heptane (\approx 0.684 g/cm^3) are nearly identical, the mass ratio closely approximates the volume ratio:

Octane Number \approx \frac{Mass of isooctane}{Total mass} \times 100 = \frac{55 g}{55 g + 45 g} \times 100 = 55

Therefore, the octane number of the fuel is 55.

Correct Answer: B. 55

Correct Answer: A. illustrations

Explanation

The definition of an illustration is a picture or a drawing or the act of creating the drawing, or is an example used to explain or prove something.

Explanation

(a) Discussion on the cultivation of Citrus spp

(i) Method of propagation- Seed - Budding- Grafting

(ii) Spacing in the field-7.Om x7.0m - 8.0m x 8.0m

(iii) Nursery practices- Weeding - Watering - Shading - Budding/Grafting of seedlings

(iv) Pests- Thrips - Scale insects -Red mites - Mealy bugs - Capsid bugs - Fruit borer - Caterpillar Aphids - Coreid bugs - citrus moths

(v) Diseases- Tristeza/dieback - Gummos scab - Root-rot- Damping-off - Black spot

(b) Definition of terms

(i) Surface irrigation This is the artificial application of water to the surface of the soil for utilization by crops

(ii) Surface drainage This is the superficial removal of excess water from the soil surface.

(c) Advantages of terms

(i) Surface irrigation

- Washes out and dilutes excess salts in the soil

- Cheap to construct/low cost

- Low labour requirement

- Easy to construct

- Used in sloppy land

- Easy to manage/practice

- Effective use of rainwater at nature friendly.

(ii) Surface drainage

- Easy to practice

- Cheap to practice

- Cheap to maintain

- Enhances seed germination

- Enhances microbial activities in the soil

- Regulates o soil pH

- Facilitates early planting

- Protects soil from water logging

- Improves soil aeration

- Improves/ increases soil temperatüre

- Easy tillage operation

- Reclaims land for agriculture

- Removes excess salt

- prevents toxicity of plants.

Correct Answer: D. there is no precipitate

Explanation

Sucrose is a disaccharide composed of glucose and fructose. In sucrose, the anomeric carbons of both glucose and fructose are involved in the glycosidic bond, which means there are no free anomeric carbons that can open to form an aldehyde group (or a ketone group that can isomerize to an aldehyde in alkaline conditions). Because of this structural feature, sucrose is classified as a non-reducing sugar.

Fehling's solution is a reagent used to test for the presence of reducing sugars (or aldehydes). It contains copper(II) ions (Cu²⁺), which are blue.

• If a reducing sugar is present, it will be oxidized, and the copper(II) ions will be reduced to copper(I) oxide (Cu₂O), which is a brick-red precipitate.

• If a non-reducing sugar (like sucrose) is present, it will not react with Fehling's solution, and the blue color of the solution will persist, with no precipitate being formed.

Therefore, when sucrose is warmed with Fehling's solution, there will be no reaction, and no precipitate will be formed.

Let's evaluate the options:

A. a silver mirror is produced: This is characteristic of Tollen's reagent, not Fehling's solution.

B. the solution turns milky: This is not a typical observation for this test.

C. a brick-red precipitate is formed: This would happen if sucrose were a reducing sugar, but it is not.

D. there is no precipitate: This is the correct outcome for a non-reducing sugar like sucrose with Fehling's solution.

The final answer is D

Correct Answer: B) fragmentation

Explanation

Spirogyra is a type of green algae that can reproduce in different ways. One of the ways it reproduces vegetatively is by fragmentation. This means that a part of the Spirogyra plant can break off and grow into a new plant. This is different from spore production, multiple fission, binary fission, and division which are other methods of reproduction used by different organisms. Fragmentation is the process of breaking off a part of the plant, which can then grow into a new plant. This is a relatively simple and effective way for Spirogyra to reproduce. It allows the plant to quickly create new individuals without having to go through the more complex process of sexual reproduction. It's important to note that fragmentation is just one of the ways that Spirogyra can reproduce vegetatively. Other organisms may use different methods depending on their characteristics and environment. For more information on Spirogyra and other types of algae, you can consult your Biology textbook.