Chemistry Questions

Carbohydrates are also called as saccharides are molecular compounds made from just three elements:

carbon, hydrogen and oxygen.

Carbohydrates are:

* a source of energy for the body e.g. glucose and a store of energy, e.g. starch in plants

* building blocks for polysaccharides (giant carbohydrates), e.g. cellulose in plants and glycogen in the human body

* components of other molecules eg DNA, RNA, glycolipids, glycoproteins, ATP

Types:

1. Monosaccharides (e.g. glucose) and

2. Disaccharides (e.g. sucrose) are relatively small molecules. They are often called sugars.

3. Other carbohydrate molecules are very large called Polysaccharides such as starch and cellulose.

Molecular compounds are those with covalent bonds between the elements and those elements are typically non metals.

Here in the given options, Ar is an element. NaI has an ionic bond. Hence, N2O4 has a covalent bond between the two non metals and is a molecular compound.

Hydrophilic molecules readily associate with water molecules and water like molecules such as alcohols.

Oxygen is the final electron acceptor of cellular respiration.

Osmosis is the process in which water molecules move from a region of higher water potential to a region of lower potential down a water potential gradient across a partially permeable membrane. It doen't requires any additional energy to do this work. 

So, Osmosis is a Passive.

Active and passive transport processes are two ways molecules and other materials move in and out of cells and cross intracellular membranes.

1. Active transport is the movement of molecules or ions against a concentration gradient (from an area of lower to higher concentration), which does not ordinarily occur, so enzymes and energy are required.

2. Passive transport is the movement of molecules or ions from an area of higher to lower concentration. Passive transport occurs because of the entropy of the system, so additional energy isn't required for it to occur.

3. Active transport requires energy to proceed, while passive transport does not require the input of extra energy to occur.

Acute diabetes results in the formation of acetone in the body. Hence such patients smell of acetone.

Rust forms when oxygen reacts with chemicals in rocks, and that is often the case with many other elements in general. Like a copper nail being exposed to the air will rust.