NEET Test 157

Formic acid and acetic acid can be distinguished using 2,4-dinitrophenylhydrazine. 

Formic acid is having aldehyde group, so it answers the above test. Forming yellow colour precipitate of 2,4-dinirto phenyl hydrazone. Whereas acetic acid does not.

The bicuspid or multicellular, the eukaryotic ovary has virtual axile (column) or axis on which spores remain. The number of cells in them is equal to the number of eggs. But sometimes the number of cells can be more due to the formation of the code board.  Argemone and marigold belong to the family Asteraceae which is characterized by basal placentation. In lemon, axile placentation is found. Dianthus belongs to Caryophyllaceae.

The covalent character in ionic compounds is governed by Fazanís Rule.

1. Larger the charge on the ions.

2. Smaller the size of anions.

3. Larger the size of the anion.

4. Larger the polarizing power larger the covalent character

𝐴𝑙𝐶𝑙₃ will show Maximum covalent character on account of the higher polarising power of 𝐴𝑙𝐶𝑙⁺³ because of its having a higher positive charge and smaller size.

BeH₂, MgH₂  is the pairs of hydrides that are polymeric in nature. Dihydrogen will combine with almost all elements, except Noble gases under certain reaction conditions forming binary compounds that are popularly called hydrides and these hydrides can be expressed as EHx (e.g., CaH₂) or EmHn (e.g.,B₂H₆) where ‘E’ is the symbol of the element.

The levels of estrogen and the progesterone hormone rise, which in turn inhibit the secretion of Follicle stimulating hormone (FSH) and Luteinizing hormone (LH). The birth control pill contains hormones that work with the body's natural hormones to prevent pregnancy by putting a stop to ovulation.

Let the maximum concentration of each solution be 𝑥 mol/L. After mixing, the volume of the concentrations of each solution will be reduced to half i.e 𝑥/2

Melting point is defined as the temperature at which a solid start to convert into a liquid state.

It is known that copper, silver, and gold all are transition metals. Their melting points are listed as follows.

Copper- 1984^oF or 1085⁰C

Gold- 1948⁰F or 1064⁰C

Silver- 1763⁰F or 961.8⁰C

Thus, the decreasing order of the melting point of the given elements is as follows.

Cu > Au > Ag

In an adult, at rest, the resting heart rate ranges from 60-100 beats/minute. The vigorous regular exercises which an athlete does helps the heart to function better and pump more blood at a lower rate as compared to the normal sedentary person. The aerobic exercises done by the athletes helps to strengthen the heart muscle and thus reducing the heart rate at rest which otherwise would be higher in a normal adult.