Soil Science - Study Mode

[#586] Most common method of determining soluble B in soil is
Correct Answer

(A) Colorimetric

Explanation

Solution: Colorimetric is the most common method of determining soluble B in soil. The colorimetric analysis is a method of determining the concentration of a chemical element or chemical compound in a solution with the aid of a colour reagent. Colorimetric assays are the simplest and cheapest methods to determine boron concentration in soil.

[#587] Vertical section of a soil is known as
Correct Answer

(C) Profile

Explanation

Solution: The vertical section of the soil that depicts all of its horizons is known as the Soil Profile . The soil profile extends from the soil surface to the parent rock material. It allows for examining the structure of the soil. A soil profile is divided into layers which are termed Soil horizons. The main soil horizons are A, B, C, D, E and O.

[#588] 50% of atmospheric mass lies within
Correct Answer

(B) 5.6 km

Explanation

Solution: The total mean mass of the atmosphere is 5.1480 × 1018 kg with an annual range due to water vapour of 1.2 or 1.5 × 1015 kg depending on whether surface pressure or water vapour data. 50% of the atmospheric mass lies within 5.6 km from the earth’s surface. About 80% of the total mass lies in the troposphere which is the lowest layer of our atmosphere.

[#589] Example of extrusive/volcanic rock is
Correct Answer

(D) All of the above

Explanation

Solution: Ingenious rocks which are formed on the surface of the Earth by the crystallization of magma are called Extrusive rocks . These are fine-grained textures because their rapid cooling at or near the surface did not provide enough time for large crystals to grow. Some examples of extrusive rocks are Basalt, Rhyolite and Andesite.

[#590] CEC of which of clay mineral is highest (120 - 150 cmol/kg)
Correct Answer

(B) Vermiculite

Explanation

Solution: CEC of Vermiculite is the highest of the given options and it is about 120 - 150 cmol/kg. CEC (cation exchange capacity) is the measure of its ability to absorb cations from the solution. It has been defined as the number of cations that are available at a given pH for exchange with other cations. Vermiculite is the name of a group of hydrated laminar minerals (aluminum-iron magnesium silicates) that look like mica. It is a hydrous phyllosilicate mineral that undergoes significant expansion when heated.