Chemistry Test - 17

The acidic nature of acetylene is due to the greater sigma electron density of the C-H bond of acetylene towards carbon, which is sp hybridized and has 50% of s-character.

So, the electron pair of the C-H bond gets displaced towards the carbon atom; and as a result, abstraction of the H+ ion becomes easier.

For isotonic solutions, osmotic pressure should be the same or equal.

For \(0.1 M~ Ca \left( N O _{3}\right)_{2}\) and \(0.1 M~ Na _{2} SO _{4},\) osmotic pressure of both the solutions are the same.

As for \(Ca \left( NO _{3}\right)_{2} \Rightarrow i =3\)

As for \(N a _{2} S O _{4} \Rightarrow i = 3\)

Osmotic pressure of \(Ca \left( NO _{3}\right)_{2}= i \times CRT =3 \times CRT\)

Osmotic pressure of \(N a _{2} S O _{4}= i \times C R T = 3 \times C R T\)

As osmotic pressure are equal, so they are isotonic.

In metals moving down the group metallic character increases, so basic nature increases hence most acidic will be \(BeO\) as \(Be\) is least metallic in group 2 elements.

\(BeO\) is most acidic in nature as the acidity of oxides decreases with increases in the electropositive character of the central atom.

Sucroseis not a monosaccharide.Sugars are categorized into monosaccharides or disaccharides.

Monosaccharides are made up of one single unit of sugar and thus cannot be hydrolyzed further into simpler compounds. Examples:- galactose, glucose, and fructose.These are the building blocks of other carbohydrates like disaccharides and polysaccharides.

Disaccharides are made up of two monosaccharides linked by glycosidic linkage and will be again broken back down into the latter during digestionSucrose is the scientific name for table sugar and is a disaccharide.

Every chemical reaction whether exothermic or endothermic has an energy barrier that has to be overcome before reactants can be transformed into products. If the reactant molecules have sufficient energy, they can reach the peak of the energy barrier after the collision and then they can go to the right side of the slope and consequently, change into products.

If the activation energy for a reaction is low, the fraction of effective collisions will be large and the reaction will be fast. On the other hand, if the activation energy is high, then the fraction of effective collisions will be small and the reaction will be slow.

When the temperature is increased, the number of active molecules increases, i.e., the number of effective collisions will increase and the rate of reaction will increase.

The powdered ore is agitated with water or washed with running stream of water. The heavy ore particles and lighter impurities are separated. This method of concentration is known as Gravity separation.

Gravity separation is an industrial method of separating two components, either a suspension, or dry granular mixture where separating the components with gravity is sufficiently practical: i.e., the components of the mixture have different specific weight.

The \(q\) ispositivewhen heat is transferred from the surroundings to the system and \(q\) isnegativewhen heat is transferred from the system to the surroundings.

The sign of \(q\) in this equation tells us whether the difference of energy in the initial system and the final system is endothermic or exothermic. If \(q\) is negative, then energy has been released from the system to its surroundings, if \(q\) is positive, then energy has been drawn in from the surroundings to the system.

Boron form bonds with other elements by sharing 3 electrons.

Boron is a chemical element with the symbol B and atomic number 5. In its crystalline form it is a brittle, dark, lustrous metalloid; in its amorphous form it is a brown powder. As the lightest element of the boron group it has three valence electrons for forming covalent bonds, resulting many compounds such as boric acid, the mineral borax, and the ultra-hard crystal boron carbide.

1. The atoms of an element having the same atomic number but a different mass number are called isotopes.

2. The nuclei which have the same mass number but a different atomic number are called isobars.

Isotopes:

• Isotopes are those elements that have the same atomic no. but different mass no.
• The mass number is the sum total of protons and neutrons.
• For example, \({}_6^{12} \mathrm{C}, {}_6^{13} \mathrm{C}, {}_6^{14} \mathrm{C}\)
• Other examples are Hydrogen isotopes named Protium, deuterium, and tritium having mass numbers 1,2,3 respectively.
• In order to identify isotopes, one must use methods to determine the mass number.

Isobars:

• The nuclei which have the same mass number (A) but a different atomic number (Z) are called isobars.
• Examples of Isobars are \({ }^{14} \mathrm{C}_{6},{ }^{14} \mathrm{~N}_{7}\)
• From above it is clear that the nuclei which have the same mass number (A) but a different atomic number (Z) are called isobars.
• Isobars occupy different positions in the periodic table so all isobars have different chemical properties, but the same physical properties.

This reaction is an example of \(\beta\)-elimination. Hydrogen is removed from \(\beta\) carbon and halogen from \(\alpha\)-carbon, hence dehydrohalogenation reaction.

Pent-2-ene is major product known as Saytzeff's product and it is more stable alkene than Pent-1-ene.

Generally, in \(\mathrm{E}_{2}\) reaction Zaitsev alkene is formed as a major product (more stable alkene).